Your donations help keep this valuable resource free and growing. Thank you.
|
199 performance build |
Post Reply | Page 123 5> |
Author | ||
Slate
AMC Addicted Joined: Feb/28/2012 Location: Airyzona Status: Offline Points: 2784 |
Post Options
Thanks(0)
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
|
||
amc67rogue
AMC Addicted Joined: Nov/05/2008 Location: Phx. AZ. Status: Offline Points: 1578 |
Post Options
Thanks(0)
|
|
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
|
||
HHaase
AMC Apprentice Joined: Oct/17/2012 Location: South Dakota Status: Offline Points: 100 |
Post Options
Thanks(0)
|
|
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 |
||
Slate
AMC Addicted Joined: Feb/28/2012 Location: Airyzona Status: Offline Points: 2784 |
Post Options
Thanks(0)
|
|
Those rods are bushed for the later .930 ish pins so the offset would be greater when going to the offset .912."
T S |
||
Slate
AMC Addicted Joined: Feb/28/2012 Location: Airyzona Status: Offline Points: 2784 |
Post Options
Thanks(0)
|
|
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 |
||
HHaase
AMC Apprentice Joined: Oct/17/2012 Location: South Dakota Status: Offline Points: 100 |
Post Options
Thanks(0)
|
|
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 |
||
amc67rogue
AMC Addicted Joined: Nov/05/2008 Location: Phx. AZ. Status: Offline Points: 1578 |
Post Options
Thanks(0)
|
|
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
|
||
HHaase
AMC Apprentice Joined: Oct/17/2012 Location: South Dakota Status: Offline Points: 100 |
Post Options
Thanks(0)
|
|
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
|
||
farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19676 |
Post Options
Thanks(0)
|
|
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
|
||
HHaase
AMC Apprentice Joined: Oct/17/2012 Location: South Dakota Status: Offline Points: 100 |
Post Options
Thanks(0)
|
|
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
|
||
Post Reply | Page 123 5> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |