199 performance build
Printed From: TheAMCForum.com
Category: The Garage
Forum Name: AMC 6 Cylinder Engine Repair and Modifications
Forum Description: AMC-made I-6 engine mechanical, ignition and fuel from basic repair to high-perf modifications
URL: https://theamcforum.com/forum/forum_posts.asp?TID=44190
Printed Date: Apr/19/2024 at 10:59am
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Topic: 199 performance build
Posted By: HHaase
Subject: 199 performance build
Date Posted: Oct/18/2012 at 5:54pm
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This is a bit of a continuation from a post I made in the 'racing' section. Short version. Want to race an SX4 is rally-america, but am limited to 3358ci displacement in the 'rookie' classses. Original plan was a built AMC 2.5 but it was suggested to go with a 199 straight six instead. I'm really liking the idea of a the 199, since it's bumping VERY close to the displacement limit. The question is, has anybody done a modern performance build on a 199? The requirements are pretty simple. It needs to go into an Eagle SX4, can't be forced induction, and displacement can't go over 3313ci. This works out to 202ci (which is why I can't just use a 258 / 4.0) So here's my theoretical engine. I'd like to build a performance 199, possibly using a 4.0 head and multiport injection, and have it swap into a 258 equipped SX4. I'm not looking for high end horsepower, top speed isn't the concern, but want a broad powerband for rally type racing. I'm still researching the 199, so please jump in and correct me when I have incorrect info. But I know the 199 has a different bolt pattern from the 258. But apparently 199's and 232's were the same block with different rotating assemblies? Could I take a later 232, with the same bellhousing pattern as the 258, and de-stroke it with a 199 rotating assembly? I'd normally say I'd just change the transmission, but then I have to worry about what's compatible with the transfer case. Can the 199/232 block even take the 4.0HO heads? -Hans
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Replies:
Posted By: Wrambler
Date Posted: Oct/18/2012 at 6:10pm
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What's the displacement using the 199 crank in the 232? Short stroke, bigger bore. The 199 engine won't bolt up to a 72 & up trans, stick shift can probably be adapted, but the clutch will be on the smallish side. Not much room in a pre72 bellhousing. The 4.0L head is doable. ------------- Wrambler 69 AMC Rambler 4.0L, 5 speed 2015 Grand Cherokee Limited 2019 Chrysler 300 |
Posted By: farna
Date Posted: Oct/18/2012 at 6:21pm
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The early 199/232 is the same block and bore, different crank/rods/pistons. Those use the "small" bell pattern only used on the small Nash L-head six and AMC sixes up to 1970. You can change a 199 into a 232 and vice versa easily -- as long as the block is pre 1971!! In 1971 AMC increased the deck height of the six cylinder block by about 1/8" so it could be stroked to 258 inches. The 71+ 232 uses the longer pre 71 199 rods on the 232 crank to maintain the 232 cubic inch displacement. The 258 uses the pre 71 232 rods. So you can't make a 71+ block into a 199 without custom length rods to decrease the effective stroke. There might be a rods out there that will work, but you'd probably need custom pistons. 4.0L rods won't work -- they are the same length as 199/71+ 232 rods. I don't think you can deck the block by 1/8", but you can have one sonic checked to find out, or if you have an old 258 block just have it decked and see what's left. The deck doesn't need to be real thick, but I don't know what minimum thickness would be acceptable... maybe 1/8"?? 4.0L heads will fit on ALL 199/232/258 blocks with no problem. On a pre 71 block you'll need to measure for pushrods. On a 72+ block the 4.0L pushrods work fine. I don't know what transmissions might bolt to the old six bell that would work with a transfer case. No auto will, only manuals. A T-14 will, but the Jeep T-14 uses a longer input shaft and won't work. You'd need an AMC car T-14 then rebuild it with the Jeep output shaft and t-case adapter. The T150 (sometimes called 150T) will work. That's a standard AMC bell trans, and would be your best bet. Both of those are just three speeds. A Ford four speed used mainly behind the 300 six in trucks (some cars, like the Granada used it also) will supposedly bolt up. It uses the T-14 pattern and can be identified easy enough -- 4th gear is overdrive. Modern Driveline was working on a T-5 adapter for TomJ, so you might ask him about that. ------------- Frank Swygert |
Posted By: HHaase
Date Posted: Oct/18/2012 at 6:40pm
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Yep, came to the same conclusion just before reading your regarding that I'd have to use the older 199/232 block. At least now I know better what I'm dealing with if I proceed with this. Great to know the 4.0 head will bolt up, my assumption is that I'd have to use 4.0 pushrods and camshaft due to the different rocker setups. If that assumption holds true, then it makes things even easier for me as there's no shortage of 4.0 cams out there. Since I'd be converting to EFI at that point, I'm not worried about losing the mechanical fuel pump drive. (Edit: I'm wrong on the pushrods, will have to measure them due to different deck heights between the blocks, and different rocker arm setups) I wonder how hard it would be to fab up an adapter plate between the 199 and a stock SX4 transmission. Never needed to use an adapter plate before, so not sure what other issues come up when you use one. -Hans |
Posted By: amc67rogue
Date Posted: Oct/18/2012 at 7:53pm
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There was someone in Phx. that made an adaptor for the early 199-232 that bolted to the slant six torqueflight . The starter is on the same side. ------------- Keith Coggins 67Rogue X code |
Posted By: HHaase
Date Posted: Oct/18/2012 at 9:42pm
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Been google digging, haven't found anybody yet that does an adapter. That's the crux of using the 199, is I have to get it onto the transmission. Not many options for transmissions that bolt to the NP119 transfer case. Hmmmm...... -Hans |
Posted By: tyrodtom
Date Posted: Oct/18/2012 at 10:07pm
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My question is why a 199 ? If the limit is 235 ci, why not build a 232? Or use a 4.0 block and 199 crank. I don't know if a 4.0 block can be decked that much. But you'd have big bore, good breathing head, strong 199 crank, it'd have to be a quick reving combination. ------------- 66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va. |
Posted By: HHaase
Date Posted: Oct/18/2012 at 10:17pm
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I just double checked the limit in the rule book to make sure, and it's actually 3313cc (not the 3358 I originally quoted). This works out to 202ci. This is the reasoning behind the 199, it's as close as I can get to the limit with an AMC block. Using a 4.0 with the 199 crank...... hmmmmm, the question there would be the connecting rods. The 4.0 already uses the same rods as the 199 used to. Not sure what the crank throw is on the 4.0. I'll dig the numbers up and see what I can find.
-Hans
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Posted By: HHaase
Date Posted: Oct/18/2012 at 10:44pm
Nope, not going to work. Even if I could get rods to work it it, the bore and stoke alone on the 4.0 would put me at 212ci using the 3" stroke of the 199. That isn't even factoring in the volume of the head chambers. That has me back at looking into the possibility of extended rods to run the 199 crank in a 258 block. And the deck height increase between the old and new blocks was .25" so I doubt I could shave that much off a 258 block. I'm basing this on the rod length change in the 232's which went from 5.875" to 6.125". So with a 199 crank in a 232/258 block, I'd need a rod length of 6.375 to de-stroke it back down to 199ci. Either that, or custom offset pistons. Either way, this is adding up pretty fast when it comes to custom parts. -Hans |
HHaase wrote:Posted By: HHaase
Date Posted: Oct/18/2012 at 10:58pm
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Well, I'll be damned. Rods from a 250/287/327 V8 are a possibility. 6.375" length, same pin type and pin diameter. No idea on the crank end measurements though. Still, worth a deeper digging. Ok, enough posting for all this stuff for tonight. Making my head explode. -Hans |
Posted By: KermitDRambler
Date Posted: Oct/19/2012 at 7:57am
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I'm pretty sure you're going to have to use an early 80's or newer block. When the Eagle line came out, AMC added bosses for the brackets that locate the front axle. Matt ------------- 1967 American wagon http://www.mattsoldcars.com" rel="nofollow - http://www.mattsoldcars.com |
Posted By: tyrodtom
Date Posted: Oct/19/2012 at 7:57am
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I misread your origional post, I thought the limit was 335 ci, not 3358 cc. You wrote 3358ci, I thought the 8 was a slip and you meant 335 ci, not 3358 cc.
------------- 66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va. |
Posted By: farna
Date Posted: Oct/19/2012 at 9:31am
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Wrong assumption on the pushrods and cam using a 4.0L head with an early 199/232 block. The cams are identical as far as the positions of the lobes and bearing journals, and they will interchange from 64-06. I used a 258 cam in my 4.6L stroker for a while. The only difference in the cams is that a 4.0L specific cam won't have a fuel pump eccentric on it (4.0L block has no fuel pump hole/boss, have to use electric). The shaft head has the rockers in the same position as the bridged rocker heads. The only difference is the deck height and the rocker ratio. The shaft rocker has 1.5:1 rockers, bridged has 1.6:1 rockers. Pushrods need to be checked for length due to the difference in deck height. For what you're doing the first thing I'd do is take a bare 72+ block to a machine shop and ask them what they think about decking it 0.125". Might be doable. Check with the local Jeep guys -- you can probably find a block cheap or free, might have to take the whole motor. The problem with using V-8 rods is the big ends might be too narrow, you'll have to check. Running a bit narrower rod shouldn't be too big a deal, the V-8 guys run narrower Chevy rods in drag motors. Don't think I'd do it in a road race motor though. Another solution would be to order custom pistons with the pin height 1/8" lower. Unless there's a rod just the right length you will have to have custom pistons to match the pin height to the rods anyway. May as well cut your losses and just order pistons to fit the stock rods. Did you talk to TomJ about that T-5 adapter? Won't help if you want to run an auto though. And why worry about running the stock transfer case? If you're doing this much work you can locate a good transfer case to match whatever trans you use. The only difficulty would be if the t-case has the front shaft on the driver's side instead of passenger side -- that won't do in an Eagle! I wouldn't worry a lot about the axle support boss. It won't be to hard to fab up a support if necessary, but a 80+ block would be the best idea. ------------- Frank Swygert |
Posted By: HHaase
Date Posted: Oct/19/2012 at 10:08am
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Yep, I came to the same conclusion with the pushrods on my end as well. Been a while since I've done this kind of swapping work. I do have to confirm the deck height change though, I think it may have been .25" higher instead of .125" higher. Difference in rod length between the low and high block 232's is .25" (6.125" compared to 5.875"). Even if I can shave a quarter inch off the block, will I still have enough thread depth for the head bolts? The thing about the stock transfer case is that I'm basing the whole project on the combination of the chassis and that particular AWD system. It has a degree of torque sensing to it, due to the viscous coupling, which will play out much better than using a later full-time box with an open center differential. I've driven a lot in trucks with the NP203 full time box, and if you break traction with one wheel.... you're stuck. Then you have to come to a complete stop to lock the differential, and once you're on hard surface again you've got to stop and unlock the diff again. Not a problem for goofing around on dirt, but a whole different story with racing. Haven't talked to TomJ yet, I got my head stuck on the connecting rod idea and just kept plugging away until I got tired last night. Will do that in a bit.
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Posted By: farna
Date Posted: Oct/19/2012 at 11:02am
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I think the head bolt holes would be deep enough, and it wouldn't hurt is they were 1/4" shorter. Hmm... you're right -- the deck of the block is 1/4" taller on the late model, not 1/8". Still, the deck might take it -- won't hurt to check. I was going from memory instead of checking again... Understood on the transfer case. Custom pistons will be cheaper than custom rods. Egge Machine can put the pin wherever you want it. You might want to talk to 74Bubblefender about pistons. He gets custom pistons for the 4.0L. Dropping the pin 1/4" might be a problem, but I don't think so. He will know more about that though, or who to ask. If you find a rod that will work you may still need custom pistons to get the pin where you need it. ------------- Frank Swygert |
Posted By: HHaase
Date Posted: Oct/19/2012 at 11:09am
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Well, dropping the pin 1/4" in the piston shouldn't be too much of a problem at all, since there's going to be plenty of excess cylinder length to work with. The block is made for a stroke of 3.8" or so, and I'll only be using a 3" stroke. So extending the skirt won't cause any problems. That makes a solid Plan-A to just deck the block. Otherwise Plan-B is custom pistons. Even if I find rods that work, I don't think they will be regular pieces and raise too many questions. -Hans
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Posted By: 72AMX
Date Posted: Oct/20/2012 at 9:38am
| Wasn't there an Indy Car in the late 60's using a 199 ci 6-cylinder AMC turbo engine, i'd imagine any info you could find on that might prove helpful. |
Posted By: tyrodtom
Date Posted: Oct/20/2012 at 10:00am
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I have one of Dick Datsons old books, it has the rod journal sizes on both. 287-327 rod big ends 2.2483/2.2490 x .902 199 rod big ends 2.0948/2.0955 x .837 You could have the 199 crank's rod journals welded and turned down to the 287's rod journals size. ------------- 66 American SW, 66 American 2dr, 82 J10, 70 Hornet, Pound, Va. |
Posted By: pacerman
Date Posted: Oct/20/2012 at 10:27am
------------- Happiness is making something out of nothing. |
Posted By: farna
Date Posted: Oct/20/2012 at 10:52am
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TomJ has it. It was actually 182 inches. 199/232 block (same bore, remember!) with 199 crank and rods sleeved down to 182 inches. It was an "Armalite" cast steel crank, only a few of those done. Later 60s/early 70s cast cranks are pretty much the same thing. See http://www.wps.com/AMC/. Scroll down to "Navarro Rambler Six". ------------- Frank Swygert |
Posted By: whalepirot
Date Posted: Oct/28/2012 at 8:33pm
 This display is at the NHRA Museum at Pomona (Ca) Dragstrip.   Sorry they're fuzzy. ------------- 1955 Nash Rambler 2-dr 302/AOD '55 F100 ('84 Vette susp/pwr '84 Shinoda Corvette 550hp 4+3 '89 BMW 735iL '95 BMW R1100S (bike) '99 ML430 '05 745Li '08 Smart Cabrio |
Posted By: HHaase
Date Posted: Apr/07/2013 at 5:35pm
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Ok, been back at this one a bit since I'm starting the build on the car. Mostly still planning on this one, probably won't start actually working on the engine for a few more months at the least, but doesn't mean I can't research in the interim. I may have found an off-the-shelf parts combo that can work... but I won't know for sure until I can do some test fitting. Probably try and pick up a couple old used-up pieces at first to confirm it all before buying full sets to build with. Using a later tall-deck 258/232 block, with a 199 crank, 4.0 rods, plus pistons out of a Buick 225 should give me pretty much what I need. Not 100% drop-in though as the 225 pistons use a slightly larger piston pin. I'm pretty sure though that a 4.0 rod can spare .0088" When my head clears from all the number crunching, I'll re-run the math to make sure this combo measures out ok and try to calculate compression numbers. I'd like to hit around 9.5 or so, but there are too many other factors I haven't looked into yet to calculate it. Next numbers I need will be the chamber volumes of the stock 258 head and 4.0 heads. -Hans Edit: Ok, double checked the numbers.
Stock 258: Stroke 3.895, rod length 5.875, compression height 1.63 = total height of 9.4525" De-stroked 199 concept w/buick pistons and 4.0 rods: Stroke 3.0, rod length 6.125, compression height 1.835 = total height of 9.46" We've got a winner! Now to calculate compression ratios assuming going from the 74cc 258 head to the 56cc 4.0 head. -Hans |
Posted By: HHaase
Date Posted: Apr/07/2013 at 7:17pm
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Scratch the Buick pistons. They're all dished, and heavily too, which would give me compression in the range of 7.5 with a 4.0 head. 258 head would be even worse, down in the 6's. Noooo thank you. But at least I got the critical measurements I needed for having a custom piston set ordered. -Hans
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Posted By: farna
Date Posted: Apr/07/2013 at 7:23pm
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The late model 258 (80 or so through 89) has ~65cc chamber as the 4.0L. The earlier sixes had bigger chambers. I'd contact Bulltear about pistons. They should be able to get you custom pin height pistons. ------------- Frank Swygert |
Posted By: HHaase
Date Posted: Apr/07/2013 at 7:43pm
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Yeah, was going to look into them or Ross and such. It's a decent change in the compression height, so it all depends on what they start from. From a raw billet it shouldn't be a problem, from a forged or cast blank it may be too much variation depending on the shape of the blank. -Hans
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Posted By: amc67rogue
Date Posted: Apr/07/2013 at 10:53pm
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The CCs in the 225 piston are about 8CCs from a Ertel catalog. .8 CCs are on the average .8 in the compression ratio . ------------- Keith Coggins 67Rogue X code |
Posted By: HHaase
Date Posted: Apr/08/2013 at 2:50pm
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Yeah, but are they actually available at all in that style? The only 225 pistons I can find anywhere right now are the sealed power models, and you could use those as an ashtray with the dish on the top. -Hans
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Posted By: amc67rogue
Date Posted: Apr/08/2013 at 3:01pm
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Every buick V6 I've seen ,225 & 231 have same style dish. My post should read 8CCs not .8 . ------------- Keith Coggins 67Rogue X code |
Posted By: Wrambler
Date Posted: Apr/08/2013 at 3:31pm
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When you get to the block, get one for a 87-90 Jeep Or 87-88 Eagle. Those blocks have the flat side on the drivers side to match the flat side on a 4.0L head. no worries about the little triangular holes leaking or needing plugged, plus they come with an excellent cast aluminum, no leaks valve cover. Does anyone do a forged 225 piston? if so the dish could simply not be machined, but that would probably be too easy. ------------- Wrambler 69 AMC Rambler 4.0L, 5 speed 2015 Grand Cherokee Limited 2019 Chrysler 300 |
Posted By: HHaase
Date Posted: Apr/08/2013 at 3:45pm
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Hmmm, didn't know that about the late 258 blocks. Shouldn't be too hard to track down a 258 Wrangler either, they made enough of the things. I've sent a couple e-mails to folks that advertise doing custom pistons for the 225 Buick and AMC I-6's, haven't gotten any responses yet though.
-Hans |
Posted By: amc67rogue
Date Posted: Apr/08/2013 at 3:48pm
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The 287 has the same bore and a .930 pin but the compression height is even taller than the buick pistons . ------------- Keith Coggins 67Rogue X code |
Posted By: HHaase
Date Posted: Apr/09/2013 at 1:09pm
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I think I looked at the 287 pistons, and the compression height was just too much. Hearing back from a couple piston folks, and the big question I need to answer is head gasket thickness and head gasket bore size. Not finding squat on this information yet.
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Posted By: farna
Date Posted: Apr/09/2013 at 1:12pm
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Compressed gasket thickness will be around 0.042". That's the figure most often seen on the 4.0L sites anyway.
------------- Frank Swygert |
Posted By: HHaase
Date Posted: Apr/09/2013 at 2:25pm
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Pardon me while I smack my head. Forgot I was going to put a 4.0 head on this, so forgot I needed the 4.0 head gasket measurements. I blame this snowstorm.
-Hans |
Posted By: Slate
Date Posted: Apr/10/2013 at 9:58pm
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If you have to up the pin size on the rods looks taoffset grinding the pin end if there is enough mass at that end to do it. That increases the rod length. You have a small amount of room to stroke the crank too cheap- about $175. You have a little more than 100cc's wiggle room. After crunching the numbers decking amounts would come down and other piston options with less rocking motion come up. T S
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Posted By: uncljohn
Date Posted: Apr/12/2013 at 10:28pm
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The explanation on connecting rod length on page one leaves me a little confused about the term "Effective stroke" Rod length has nothing to do with stroke At least as I have read and understand theory. Rod's connect the crank shaft which is the part of the engine that determines what the stroke is to the piston which moves up and down. A long rod will push the piston further up but it also starts further up, a short rod on the other hand does not push the piston as far but then again it does not start as far up. The stroke is the same on both examples. As the 199 block is of the same family as the 232 and the 258 with out looking up any dimensional variation between the two and the need to bolt up a particular engine to a particular transmission. This being a block built from 1972 on to a transmission and bell housing combination it becomes a matter of how high the piston will rise when pushed by a stroke of 3 inches of the 199 vs 3.5 inches of the 232. The stroke is a constant no matter what connecting rod is used. The question is where is the piston going to stop at the end of a 3 inch stroke and that will be a function of how long the rod is. Remember it not only is going to stop higher, but it also is going to start higher. It is only going to move 3 inches no matter what. My TSM indicates that the 232 crank bearing measurements are going to the be same as the 199 so the assumption is that a 1973 232 which bolts to all the later transmissions will also accept a 199 crank with out a problem. As the bore for both engines are the same, then the 199 rod and piston should also work. Leaving the only unknown as to how great a space is left above the piston known as deck height to the top of the block and the size of the combustion chamber. And if needed can the amount of the material at the top of the block be milled off safely. My answer is I don't know but it is one that is a straight forward thing to determine. So I guess I am not sure I see a problem. Yes the 258 in the middle 70's was a taller block, but the 258 was derived late too. So a 72ish 232 block it seem to me would work for what you want to do. Unless of course I am missing something here. All wheel drive SX4 might be a problem but 2 wheel drive Gremlins and Spirits would not or anything similar. I have an early 232, I think it is a 73 and there are mounting hole variations between it and a later 258 for a lot of accessories. But I can bolt up a bell housing for a 5 speed and install a Merkur 5speed I have on it if I wanted to. I guess if it boils down to what block can be used as being compatible to bolting up to a 4 wheel or all wheel drive transmission if jounal sizes are the same all the way up the line the next question is how much combustion room do you have left and what can be done about it. Decking a block and milling a head is Standard operating procedures in engine building. Before I would worry about exotic solutions, I think I would worry about the stock parts first and what you can get with them and how to tune them for maximum performance. You ought to be able to turn a short stroke engine pretty tight. Reliably. I can reliably turn my 258, a typical long stroke cat to 5000 pm. I don't have enough cam to look at higher rpms. But my 232 which will be build later on should be an easy 6500 rpm engine. And develop fair usable hp with 9:1 compression. ------------- 70 390 5spd Donohue 74 Hornet In restoration 76 Hornet, 5.7L Mercury Marine Power 80 Fuel Injected I6 Spirit 74 232 I-6, 4bbl, 270HL Isky Cam |
Posted By: farna
Date Posted: Apr/13/2013 at 7:33am
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64-70 six blocks are the "short deck" blocks. 71-06 are all "tall deck" -- I seem to recall them being 1/8" taller than the short ones, might be 1/4". The monkey wrench in this is that the 71 tall deck blocks used the old small six bell housing pattern on the block, the 72-06 blocks use the larger AMC V-8 pattern. That comes in handy is wanting to use a 258 in an older car, but you have to have that 71 only block. The accessory mounts changed for 1974. The bolt pattern for the timing cover remained the same, but the sizes of some of the bolts changed so they could handle carrying accessory brackets. You can put a later cover on an earlier block, but have to use washers under some of the bolts to cover the larger holes and you have to use the old style accessory mounts. It's not pretty, but I've seen it done. To go the other way around would require drilling and tapping some of the holes larger. I don't know for sure if there is enough "meat" in the bolt hole areas of the older block to do this, but I would suspect so. Even the 258s were turned up to 6500 rpm in race trim. I wouldn't build any of the sixes to turn over 5000 unless it's a mostly strip car. They just aren't as good at high rpm power. Build to take advantage of the sixes great low speed torque instead and you'll be happier with a street car. If you want to run high speeds you will likely be happier with a V-8, though a short stroke six turning tight would be great in a light car. ------------- Frank Swygert |
Posted By: uncljohn
Date Posted: Apr/13/2013 at 8:21am
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An engine that is rated at about 190 ft pounds of torque at around 1800 or so rpm does not come under the heading of great. At least not in my book anyway. If the idea is to build a race motor than it is by definition one that will turn higher rpm's which is a by-product of building a RACE motor. And as one way to define an engine is a positive displacement air pump one way to get it to develop more HP is to get it to pump more air. And the standard method of doing that is to give the capability of turning more rpm's. A formula commonly used to develop a motor or engine for any form of racing. And that is not dependent on the number of cylinders or the configuration of them. It is however partially dependent on the length of the stroke used in any particular motor. A physically long stroke motor is not really very happy at higher rpm's. However many have lived there for long periods of time. A short stroke motor is happier. One with a 3 inch stroke can mechanically be turned at higher rpm's with fewer inherent problems. As compared to say one with a 3.5 inch stroke or a 3.9 inch stroke. An 401 cu in AMC engine has a factory stroke of about 3.7 inches. And the same rules apply to it. Just because it can be turned that tight or tight by what ever definition is used, does not mean it has to be driven there at a constant speed while driving. It means the capability is there. American inline six cylinder engines by in large are throw back in concept engines to the 1930's when high compression was 6:1, speed limits were 45 mph and it was rarely expected to see one travel at a mile a minute. The carburetors were tiny and still are and they were under-cammed and what was called under square with bore size generally smaller than stroke was long to build a long narrow engine that fit under long narrow hoods. And as the tooling already existed to make engine of that size as the modern engine developed as an option to them, they stayed in production as an inexpensive base engine that worked sort of an people bought. Jaguar, BMW, Mercedes Benz, and many other racing engines were developed using the I6 engine which is an indication only that configuration does not make an engine but how the configuration is applied. Even Jeep had an overhead cam I-6 that became notorious as a high performance racing engine in another country that did not have a pre-concieved notion that it could not be done. Do not let the old wives tale that an inline I-6 is a great torque motor thus can not be built into a great racing motor deter you from doing so. In the first place it is a lousy torque motor. In the second? It makes a great racing motor too. To me, the idea of building a modern equivalent of something that is built to a very small displacement sounds like a challenge that might be kind of fun using an AMC based parts box. I am not so sure that a 4.0 head is the best choice for it though taking an overall look at the objectives. Early 232's had a rocker shaft rather than the stud mounted rockers. Using that head and pocket porting it makes a certain amount of sense as the platform to mount the rockers on, a shaft is a stable platform at higher rpm's. Just a though anyway, but one I am going to utilize if my 232 has a shaft based valve system. I don't know that it does, but when I get around to looking if it does I am going to be satisfied that it has one and just go ahead and use it. It is old enough that it could be. It is like many projects I have a round-tuit project. I need to finish 2 others first. ------------- 70 390 5spd Donohue 74 Hornet In restoration 76 Hornet, 5.7L Mercury Marine Power 80 Fuel Injected I6 Spirit 74 232 I-6, 4bbl, 270HL Isky Cam |
Posted By: farna
Date Posted: Apr/13/2013 at 8:35am
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The max amount of torque an engine produces is directly related to size (cubic inches). The sixes don't put out more torque than a larger engine. The max torque rating on the one mentioned is 190 ft/lbs, but the torque curve is rather flat before and after. An in-line six builds torque quickly then holds a relatively flat curve for a long period (of course this is affected by cam choice). That same six probably produces 140-150 ft/lbs at 1000-1200 rpm, not much over idle speed, then ramps up to 190@1800, and tapers off to the 140-150 range at around 4000 before falling flat (again, due to cam). That's great for a street car. Almost any engine can be made to run with the right mods. I'm not saying it can't be built as a high rpm race motor, I know it can. I was just pointing out that it's main forte is low rpm torque, and it can be built to take advantage of this AND perform with the right trans and rear axle ratio (a five speed and mid 3 gears usually does the trick). ------------- Frank Swygert |
Posted By: uncljohn
Date Posted: Apr/13/2013 at 8:58am
The point though is that is a function of two things. Gross under carburetion, a carburetor that when the numbers are run is out of it's operating window at some where around 3500 rpm AND a cam shaft designed to fall flat on it's face. A basic 1930's era performance window. The first thing an engine that is oriented to a performance application gets rid of and replaces them with a carburetor that is suited to run at higher rpms efficiently and a cam shaft that will let it happen. Cylinder configuration has nothing at all to do with that. The rear wheel dyno. curves curves graphed from 2700 rpm to 4000 rpm and limited by the about 190 cfm carburetor that at the time was on my 258 cu in engine show 170 ft lb of torque at 2700 rpm and 100 ft lb of torque at 4000 rpm and anything but flat on the torque curves but a flat hp curve from about 3000 rpm to 3700 rpm with a peak at 3300 rpm where ran out of carburetor. And all of that due to two things, the choice of cam, a mild street cam and the factory stock carburetor which was limiting things by being too small. Eliminating the restriction of the carburetor by installing a fuel delivery system with a higher CFM rating moved the operating range of the engine up and easy 1500 rpm yet as still drivable as a street car with civil manners using a final drive of 2.53:1 which gave a gearing of about 32 mph/1000 rpm which says it would cruise happily at 2000 rpm all day long at 62 mph or 3000 rpm all day long at 93 mph. Despite a significant increase in RPM Capability the need to run it there was not required. It pulled fine at the lower rpm. It just did it faster because of the increased power band. They make a fine race engine when treated as one. ------------- 70 390 5spd Donohue 74 Hornet In restoration 76 Hornet, 5.7L Mercury Marine Power 80 Fuel Injected I6 Spirit 74 232 I-6, 4bbl, 270HL Isky Cam |
Posted By: HHaase
Date Posted: Apr/13/2013 at 11:19am
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And that's the crux of it, de-stroking to a 199 is the base requirement of the rules set I have to build for, which has a max displacement of just over 200ci. Using the 199 bore/stroke with a .030 overbore will put me just 3cc under that limit. Can't ask for better than that! However, I HAVE to use a 258 block due to transmission requirements for the AWD transfer case, plus mounting of the front differential in the Eagles. Only late 258 blocks have the proper mounting hardware and transmission options to fit in the car. It's as big of an engine as I can possibly put in the car, and still be rules legal. Once I get the rotating assembly sorted out, everything is will be a performance oriented build. This means a new camshaft, pistons are actually going to be ordered for 9.5:1 compression, the 4.0 head for better flow, and I'm leaning heavily toward EFI actually. For the racing I'll be doing, a lower RPM powerband is preferred, and I'm going to try and curve everything for life in the 2000-4000 powerband if possible. If I can hit 200hp, I'd be very happy. Remember, this is rally racing, not circle track. It's more about acceleration from low to moderate speeds, which is where an I6 shines due to the torque curve. Most competitors are going to be running 2.5 Subaru's and such, so I don't see any disadvantage in this engine. Fuel management will use the Megasquirt system, which is a fully programmable EFI system which can use wide-band O2 sensors. I've used it before on a 258, and it's a great system which as only expanded since the last time I used it. I haven't decided yet if I'll also run ignition management through the computer or not, it is an option with current Megasquirt systems. Either way I'll go with either HEI or a Uni-lite distributor. I've used both, and really like both systems, but the Uni-lite I find easier to work on. -Hans
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Posted By: farna
Date Posted: Apr/13/2013 at 11:47am
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Hmmm... the best I can come up with is a 0.16" difference in deck height between the early and late blocks. You'll have to check with a machine shop and see if you can take that much off the deck of the late 232/258/4.0L block. Other than that you'll have to have custom pin height pistons and figure out what rods to use. Might be a rod from some other manufacturer that could be modded to fit though. That's right, only the 99+ 4.0L blocks don't have the bosses to mount the Eagle front diff. Some of the mid 90s blocks may not have the bosses drilled and tapped, but they should be there -- just in case you wanted to use a 4.0L block. It wouldn't be hard to make a bracket extending from a motor mount to mount the front diff though. That's no help on the trans though. It would be possible to use the new T-5 adapter on the old T-96/small six bell, but you'd have to find a CJ T-5 and x-fer case to bolt to it. Not the best for a higher powered engine. ------------- Frank Swygert |
Posted By: HHaase
Date Posted: Apr/13/2013 at 6:19pm
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Can't use a 4.0 block, the bigger bore will put me well over the displacement limit. All things considered, I'll need custom pistons anyway in order to hit the compression ratio I want, so I'm planning on going with 4.0 rods due to their higher strength and then make up the remainder with custom pistons. -Hans
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Posted By: amc67rogue
Date Posted: Apr/13/2013 at 6:19pm
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The 81 up 258 blocks are 30 pounds lighter than the 80 and earlier . Get a main car girdle from a late 4.0 to heap support the mains. It might not be necessary but it's something to think about. ------------- Keith Coggins 67Rogue X code |
Posted By: HHaase
Date Posted: Apr/13/2013 at 6:50pm
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Trying to get some quick funds together actually, somebody not too far away has a complete '88 Wrangler power pack for sale at a decent price. This would give me the late 258 block and an AX15 transmission bolted to it, which is what I really want. But budgets are REALLY tight right now, still out of work unfortunately. Time for a grand E-bay sale of a lot of stuff.
-Hans |
Posted By: Slate
Date Posted: Apr/16/2013 at 3:26pm
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A piston with a compression height of 1.81" that uses Ford's .912" pin offset by half the total difference from the stock nominal .9288" diameter in Eagle's 6.50" 4.0 forged rods - you'll have to locate a set - looks like Eagle doesn't make them anymore would put you about 9.45. Then you'd have a reasonable amount to deck the block. I wouldn't worry about lugs for the axles. Brackets can be built. How much you have to deck is the important thing. Later blocks are taller. T S |
Posted By: Slate
Date Posted: Apr/16/2013 at 3:29pm
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Those rods are bushed for the later .930 ish pins so the offset would be greater when going to the offset .912." T S |
Posted By: HHaase
Date Posted: Apr/18/2013 at 5:33pm
Yep, but I also have to worry about bellhousing bolt patterns. Not too many transmission options out there that can work with the original transfer case in the Eagle, and for rally racing I really need to keep that viscous coupling full-time case. I could probably make an original 199/232 block WORK, but I still think that using a combination of as many factory parts as possible in a 258 block with only custom pistons would be the most cost effective option. No matter which way I look at it, I'll need the pistons just to get the compression ratio I want with the 4.0 head. I also have to worry about being able to repeat this feat in the future, in case I blow the thing up at some point. I've found a few people on other forums talking about this build, but I don't think anybody has actually gone ahead and done it yet. -Hans |
Posted By: amc67rogue
Date Posted: Apr/19/2013 at 8:02am
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The 265 chevy had a 3.75 bore , the compression height is 1.800 and there flat tops . Just a thought. ------------- Keith Coggins 67Rogue X code |
Posted By: Slate
Date Posted: Apr/19/2013 at 11:40am
Yeah, true. Looking around is free. You might find through Advnce Adaptors or asimilar company an adapter. That would simplify things. If you want a later later block- one that is up to almost .250" taller than a 199/232 early block then you have to find out how much you can safely mill. The lugs are nice but are they worth having to lop off what you can and then go with a heavy tall piston?Brackets are possible. You just need a lugged block to use as a guide. Then you could go with an earlier post 71 block and deal with much less jumping through your rear to get the piston height. T S
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