The AMC Forum : Money is no object, 3.75L I6 http://theamcforum.com/forum/ This is an XML content feed of; The AMC Forum : 6 Cylinder Engine Repair and Modifications : Money is no object, 3.75L I6 Sun, 19 May 2013 03:21:14 +0000 Sat, 14 Apr 2012 19:32:27 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 10.03 360 theamcforum.com/forum/RSS_post_feed.asp?TID=38472 The AMC Forum http://theamcforum.com/forum/http://www.theamcforum.com/forum/skin_images_amc/forumheader.png http://theamcforum.com/forum/ Money is no object, 3.75L I6 : I agree, would have been nice!... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353394.html#353394 Author: farna
Subject: 38472
Posted: Apr/14/2012 at 7:32pm

I agree, would have been nice! Maybe run them in Baby Grand National NASCAR too. Baby Grand was 5.0L and under. Junior Johnson ran a 68/69 Javelin in Baby Grand with a 290. At least I think it was JJ... not sure if it was 68 and 69 or just one of those years. But a six cylinder class would have been nice. Well, there were six classes for the dirt tracks and amateur/hobby asphalt tracks.]]> Sat, 14 Apr 2012 19:32:27 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353394.html#353394 Money is no object, 3.75L I6 : In some ways I always thought... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353326.html#353326 Author: Spin Doctor
Subject: 38472
Posted: Apr/14/2012 at 1:36pm

In some ways I always thought the SCCA should of had a second level Trans Am class (or third as they had the under 2.0 Liter class) for 6 cylinder compacts with a displacement level in the 200 CID range. I know I love a nice v8 (my '68 AMX had a 390, then came love, then came marraige and you know the rest) but this might of gotten the manufactures to build a nice class of pony and compact cars with some serious 6 cylinder performance potential*. But it was the 60s and v8's ruled the roost.
 
 
]]> Sat, 14 Apr 2012 13:36:04 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353326.html#353326 Money is no object, 3.75L I6 : amc67rogue wrote:Tomj ; Does... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353246.html#353246 Author: tomj
Subject: 38472
Posted: Apr/13/2012 at 11:30pm

Originally posted by amc67rogue amc67rogue wrote:

Tomj ; Does that motor have a stock 199 crank or a billet ? If is't a stock 199 how many counter weights does it have ?  


Eight!

http://www.wps.com/AMC/Navarro-turbo-motor/images/crank1.jpg
http://www.wps.com/AMC/Navarro-turbo-motor/images/crank2.jpg

I talked to Navarro's engineer in person, he said AMC gave them all the parts they wanted, and that all the cranks were factory parts. As far as he recalls, there was never a steel billet crank, only cast factory parts. I've written this before, but the rumors persist without any evidence and in the face of first-hand (OK, second, from me) information.

Originally posted by Slate Slate wrote:

 An engine with walls that thick is screaming to go turbo.
 


It *was* a turbo motor... Navarro made two versions (at least), a "550 hp" single turbo, and a "750 hp" twin turbo. Mine is, as far as I know, one of the test mules of the single turbo. This particular motor was run at Buttonwillow, a road race track, with the Indy dry sump and it went dry in a turn and scored the crank. The guy said he'd never seen Barney so mad for makign such a dumb mistake. The scoring is minimal, and my pile came with a set of .010" under bearings so it seems clear the intent was to rebuild it, but who knows of course, it was a long time ago.

Recall this was the late 60's, so turboing was not common I think. The twin turbo motor had Hilborn mechanical fuel injection (I have some of those parts) but at least an early single-turbo motor had a huge Delorto carb.

Mine's got stock main bearing setup; another ex-Navarro employee I talked to, still alive, Marino, said the twin-turbo block had been converted to four-bolt mains.

Neither motor had an intercooler. The 750 hp motor was run at 45psi boost! So air temp must have been insane. Hence the overkill cyl walls, I assume. Intercooling should have been there but no pictures I've seen shows it.

Car #50 never qualified, so all this stuff fell into obscurity.

But it does tell about the capabilities of the AMC six. With an intercooler and EFI 500 hp ought to be easy enough.

]]> Fri, 13 Apr 2012 23:30:06 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post353246.html#353246 Money is no object, 3.75L I6 : That's a Pontiac Jim (carnuck).... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352950.html#352950 Author: farna
Subject: 38472
Posted: Apr/12/2012 at 2:02pm

That's a Pontiac Jim (carnuck). They were real good ones! ]]> Thu, 12 Apr 2012 14:02:27 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352950.html#352950 Money is no object, 3.75L I6 : farna wrote: The head... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352948.html#352948 Author: carnuck
Subject: 38472
Posted: Apr/12/2012 at 2:00pm

Originally posted by farna farna wrote:

The head is the biggest issue, if you want a crossflow head. If you're redesigning the head, go with an OHC design -- no point not to. Before reinventing the wheel, check other six cylinder heads though. Find one with the came bore centers and there's a good possibility it can be modified to bolt to the AMC block. Me, I think the last couple 4.0L heads are really good, good enough that the effort and expense for a new head is questionable. Ron Waters said he turned a 258 to 6000-6500 rpm all the time, and that was without the benefit of even a 4.0L head (all of which are substantially better than the 258 and older heads).

There is a roller cam available, but durability is questionable. The cam is ground from a standard cam blank and then surface hardened. No one knows how long it will take to wear through the hardening -- I think the company suggests somewhere around 25K miles? If you're spending money get a hard billet roller cam and work with the 96 or so head.

SOME 4.0L blocks can be bored out to 4". Beware of core shift -- have it sonic checked first! Sometime around 92-93 Chrysler took a bit of metal out of the block, so get an early one. I'd go ahead and look for a 87-90 Renix EFI block just to be sure.


Here's your OHC motor (Pontiac, but it's still a retrofitted pushrod motor)

http://i86.photobucket.com/albums/k102/willthethrill256/t3.jpg



Edited by carnuck - Apr/12/2012 at 2:01pm]]> Thu, 12 Apr 2012 14:00:44 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352948.html#352948 Money is no object, 3.75L I6 : tomj wrote:lol, i have a sort-of... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352906.html#352906 Author: Slate
Subject: 38472
Posted: Apr/12/2012 at 12:30pm

Originally posted by tomj tomj wrote:

lol, i have a sort-of "money no object" cylinder head .... check out this AMC part number:

http://www.wps.com/AMCavarro-turbo-motor/s/RD-top1.jpg - http://www.wps.com/AMC/Navarro-turbo-motor/images/RD-top1.jpg

and porting....

http://www.wps.com/AMCavarro-turbo-motor/s/RD-combust1.jpg - http://www.wps.com/AMC/Navarro-turbo-motor/images/RD-combust1.jpg

and big valves...

http://www.wps.com/AMCavarro-turbo-motor/s/h2-wrong-valve.jpg - http://www.wps.com/AMC/Navarro-turbo-motor/images/h2-wrong-valve.jpg

Alas, my money is severely limited; but I just inventoried all my parts and i'm thinking of building a < 200ci carbureted 6000rpm six cammed for 4000 - 6000. Never had an engine with a wild cam but this head is all ready for that. The block is sleeved such that with the 199 crank it's 181ci.

Will use 4.0 rods and since the cyl walls are currently an insane 0.400" thick I'll just bore it for whatever pistons I can find that work.

 An engine with walls that thick is screaming to go turbo.
 
T S
]]> Thu, 12 Apr 2012 12:30:45 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352906.html#352906 Money is no object, 3.75L I6 : Tomj ; Does that motor have a... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352886.html#352886 Author: amc67rogue
Subject: 38472
Posted: Apr/12/2012 at 10:53am

Tomj ; Does that motor have a stock 199 crank or a billet ? If is't a stock 199 how many counter weights does it have ?   ]]> Thu, 12 Apr 2012 10:53:35 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352886.html#352886 Money is no object, 3.75L I6 : lol, i have a sort-of &#034;money... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352779.html#352779 Author: tomj
Subject: 38472
Posted: Apr/11/2012 at 9:35pm

lol, i have a sort-of "money no object" cylinder head .... check out this AMC part number:

http://www.wps.com/AMC/Navarro-turbo-motor/images/RD-top1.jpg

and porting....

http://www.wps.com/AMC/Navarro-turbo-motor/images/RD-combust1.jpg

and big valves...

http://www.wps.com/AMC/Navarro-turbo-motor/images/h2-wrong-valve.jpg

Alas, my money is severely limited; but I just inventoried all my parts and i'm thinking of building a < 200ci carbureted 6000rpm six cammed for 4000 - 6000. Never had an engine with a wild cam but this head is all ready for that. The block is sleeved such that with the 199 crank it's 181ci.

Will use 4.0 rods and since the cyl walls are currently an insane 0.400" thick I'll just bore it for whatever pistons I can find that work.

]]> Wed, 11 Apr 2012 21:35:07 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352779.html#352779 Money is no object, 3.75L I6 : If money were no object, why stop... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352549.html#352549 Author: Stroh
Subject: 38472
Posted: Apr/11/2012 at 7:01am

If money were no object, why stop at 3.75L? 

Have a 4.0 block sleeved for 4.125 bores and crank with a stroke of 4.00 or longer for a displacement over 320 ci (5.25L).  Darton sleeves for a SBF should be able to be made to fit as the 351w's have a similar deck height and exactly the same bore spacing.  Money is no object, so the billet crank will be able to handle whatever RPM you want to throw at it.
 
Then come up with a cylinder head that flows 275-300 cfm on the intake with at least 75-80% of that on the exhaust.  That would make some serious power.
 
I seem to remember the 300ci ford pro stock cars from the 70's that had two 351 Cleveland heads welded together on top of them.  I've been wondering if the same could be possible with two SBF heads onto an AMC, because they share the same bore spacing and maybe somewhat close head bolt patterns (i.e. four head bolts per cylinder).
 
 
]]> Wed, 11 Apr 2012 07:01:03 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352549.html#352549 Money is no object, 3.75L I6 : No, all the road racers don&#039;t... http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352460.html#352460 Author: farna
Subject: 38472
Posted: Apr/10/2012 at 7:17pm

No, all the road racers don't use the heavy crank, I know a few who use the light one with just as good results. The ones who use the 12 CW crank cite "greater strength" more than easier balance. The ones with a lot of money in the motors balance the rotating assembly anyway, even though the six is inherently balanced. I've talked to several road racers who have built sixes. They just don't like the lighter crank because it is PERCEIVED to be weaker, and they don't want to risk finding out at 6000+ rpm. I can't really blame them for that, but the Jeepers have pretty much proven that the lighter crank is just as tough, at least in low to medium rpm applications (under 5000 rpm), even when there is a lot of torque stress on the crank. Take rock crawling -- spinning a tire in the air then suddenly getting traction usually breaks things, and on rare occasion it's a crank. From the guys I've talked to just as many 12 CW cranks break as the light ones, but both are far between.

You have some good arguments for a 12 CW crank as far as balance. Where the weight is placed around the crank is more important than the number of weights, especially with seven main bearings, but you do have valid arguments -- especially if you want to spin the thing 6000+ constantly. A short stroke built-to-the-hilt six for racing would probably need to do that. Your formula would work with existing parts and technology, would just cost a lot, and would be a "high strung" engine. Don't know if it would be very streetable, but it sure would be a lot of fun somewhere like Road Atlanta!!
]]> Tue, 10 Apr 2012 19:17:22 +0000 http://theamcforum.com/forum/money-is-no-object-375l-i6_topic38472_post352460.html#352460