Need help with information for actual race vehicle

[TeamHazardRally]

Hey guys, long story short I don't know the ins and outs of anything related to 60 deg. swaps. I'll tell you what I have and what I can do and if you guys could, tell me what I need from what years to do what I need. What I have; 1986 jeep comanche pickup rally race truck. What I need(or at least think I need) a 3.1 liter swapped in. So here's the deal. The class we're in says that we have to use an engine that the block is at least based on something that was available in that vehicle. And the class we're in says that we can go as high as 3.3 liters if the engine is a pushrod. Since for one or two years the comanche was available with a 2.8, the best I can figure is we can use up to a 3.1. So my question is. What do I need to do this swap. It is Rwd. In the garage is an AX-4 an AX-5 and two toyota W55 trans. Will it be easier to find some transmaro bird that is already RWD with the 3.1 or is it just as easy to put in the MUCH more available FWD engine. If so what will I need to do that. I don't really know about these things so I will claim ignorance. Hopefully someone who knows a bunch about this can break it down easy and I can get a response like "you need an engine and wiring harness from these years and these models, with this bellhousing, with this tranny, and this clutch from this year thing and it will work" Someone please help, our next race is june 4,5,6 and the 2.5L 4 cyl is just too damn slow. If anyone wants to see the truck search Team Hazard Rally on youtube or go to TeamHazardRally.com

Thank you,
Lee

[bszopi]

Welcome!

What you are wanting to do should be pretty easy, and there are several people on the site that will be able to tell you exactly what you are wanting. I guess the first question I would ask, though, is are you willing to do any modifications to the electrical system, or do you have the means to do any custom fabrication (in the short time frame you have)? Reason I ask is, the FWD engine would be a great candidate for what you are wanting, but the intake system doesn't allow for a distributor (which I'm pretty sure you have), so you'd have to look into going to a DIS system, or custom fabbing an intake to work with the aluminum heads (there has never been a alum head engine available with a distributor).

Report back, and we can start giving you ideas!

[TeamHazardRally]

Correct me if I'm wrong but wouldn't the donor engine come with the ignition system? As far as fabbing goes, I'm a welder by trade so simple things like you have to cut this pipe and weld it back on at a different angle, we could probably do in our given time. However if it's you have to make an intake manifold, I don't have the time or resources for that. Also what kind of modifications to the electrical system are we talking about. The plan would be to buy a donor car outright that has the engine we want and pull that and the whole wiring system and slap it in the truck. Well ok the plan is to park the donor car next to the truck and wake up the next morning with it done, but I somehow don't think that's going down. So what else am I looking at that needs to be done for this swap. It's a pretty clean slate in that truck. we would be pulling pretty much everything in the engine bay and starting fresh.

[bszopi]

Yes, the donor engine will come with the ignition system, but it probably won't work right with your stock ECM (if you even have one?). The electrical I am talking about would basically be installing a new ECM to control the new engine. Unfortunately, to get the best engine (2000+ 3100), your ECM wouldn't come from the same car (you would want to go with an OBD1 setup for what you are doing). For what you are doing, it may not be that bad of a job to do, but you would need a pre-93 car for the wiring harness and ECM, and a later model (1994+, although as stated above, 2000+ would be best) car for the engine.

Do you have any info on the existing ECM? There is a guy on here (robertisaar) who can probably hook you up with the required schematics for your truck's existing wiring, as well as your donor vehicle's wiring. It sounds like a lot, but it would definitely be worth it.

And as far as fabrication goes, yes, I did mean making a new intake manifold...

[TeamHazardRally]

making a new manifold just aint happening. Too much involved and too little time. we would be pulling the entire wiring out of the truck. Right now the truck has the AMC 2.5L 4 cyl. so nothing from that will work with it. But being a dedicated race vehicle everything is pretty striped anyway so it won't be that big of a deal to transplant the entire wiring harness out of it.

[geoffinbc]

Forget the aluminum head FWD stuff you don't have time. The quickest route is a .040" over 3.1L which gives you just over 3.2L and the increase stroke will really increase the torque. Find a Camaro with a 3.1L or if thats too hard to find then get yourself an 88 or later 2.8L S-10 engine (because you need a 1 piece seal block) and find a 3.1L, 3.4L, 3100 or 3400 crank from ANY FWD Car with those motors. The take it to your machine shop and have a set of new .040" over 3.1L pistons thrown on and the crank balanced, clearances checked and put it all back together.

Since you have a 2.5L then your going to have to figure out the engine mounts. I am not sure if Jeep used the same frame side mounts for all the engines. But they did use a 2.8L in the Cherokee so that might help you out for parts. Otherwise everything you need will come from a 4X4 S-10 which is identical to the motor used in the Cherokees.

For the engine wiring you can do some splicing and extending or grab an S-10 harness. I would however suggest a 3.1L ECM from an Isuzu Rodeo or Chevy Lumina APV van with a 3.1L TBI. To increase performance you can bore out the intake and bolt on a 4.3L TBI unit. Or I can sell you the kit. I would not suggest a carb because you will be dealing with flooding and starving in the kind of environment you are running in for more reading check out my website. The 3.2L I built for my Trooper should give you some good pointers.

[bszopi]

Thanks, Geoff, for chiming in. I was hoping you would.

Oh, and since you always tell people to check your site, but never give the URL, here it is -> http://members.shaw.ca/betterthanyou/

You probably need to add that to your sig. Although, now that I look, it is available from your profile.

[95Grand-Am]

How strick are the rules because A 3.4L is acully a 3.349L is .049L too much?

[geoffinbc]

Thanks, Geoff, for chiming in. I was hoping you would.

Oh, and since you always tell people to check your site, but never give the URL, here it is -> http://members.shaw.ca/betterthanyou/

You probably need to add that to your sig. Although, now that I look, it is available from your profile.

Shit we don't have a "www" button on this site like the others. Guess I will have to remember that

[TeamHazardRally]

So after careful examination of the rules and redoing my calculation of the multipliers for displacements, it turns out that the max displacement is 3080 cc or 3.08 L and yes they are strict. If we start winning and they have a reason to suspect something, they will tear the engine down. So looks like we need to find a 2.8 out of an s10 or a transmarobird. So what quick power mods can we do to a 2.8. And I know this is super general but what kind of hp and maybe torque am I looking at. One of the concerns is we do all this work and bust ass to get this thing running only to have the truck STILL not get out of it's own damn way. But either way, thank you for all the info thus far, I really do appreciate it.

[Guest]

What do the rules state as far as allowable heads, and induction?

I know some classes in racing restrich aluminium heads, some restrict EFI, etc.

If I were to do this again, yes I have done it before, just not for all out racing, is this:

RWD 2.8L block, crank and pistons (since you need to stay under 30.L)
3100 or 3400 FWD top end, with either the "3100 SFI/3400 SFI" lettering ground off, or use the '96-'98 Minivan blank uper intake manifold, so that people don't think you have something larger than you do.
Crane 272 cam, or since it will be N/A (assuming), maybe a Schnieder Cams solid roller cam (if rules allow), they have some 660 cams with some aggresive profiles.
You will need to DIS with this, so you will to fabricate a timing wheel to run it. I can show you pictures of mine, if you are interested.
Use an ECM with the Service number '7730, if you can mount it in a pretty sealed up environment, or '7727 if it will be pretty much exposed. This will need to be tuned, and can help with some selection of proper programs and such. I can also point you in the right direction for equipment.
19 to 22 lbs/hr injectors should get the job done, using a Walbro inline fuel pump.

With these RWD pistons and FWD heads, with the 2.8L stroke, you should get about an 11:1 statoc compression ratio, which shold make for some good throttle repsonce, and with the large port top end and proper cam, should rev fairly high, 6000+ if tuned right.

This would be a tight schedule to get done, and would be much easier over a winter project, or a couple months anyway, but this would likely be the direction I would go, as long as rules allowed.

This is just a basic overview with some key points, some things could be changed around, but this would work well, IMO.

[TeamHazardRally]

wow definatly good info. the rules state that there can't be any forced induction ( they have separate class for 2wd forced induction) and that the block must be derived from something available from the manufacturer and must be no more than 3080 CC. So as far as heads, I could use heads from a god damn space ship if I wanted to... as long as I get them to work with the block. So really the rules are open I can build an engine however I want with what ever parts from wherever as long as the block is from the vehicle manufacturer and is no more than 3080 cc. So that being said I can use anything from dodge chrysler jeep eagle. The list of engines that have been in contention are the 4G63 from the eagle talon, but the conversion bellhousing is expensive and makes about 145 horse 120 torque, the GM 2.8 easier to find parts and there is aftermarket support. Or the 6G72 from a dodge stealth. pretty heavy but makes 220 horse out of the box but no RWD trans applications without heavy custom fabbing. So really it all kinda points to the GM. I like the Ideas for building a 2.8 and I like that it will make 11:1 compression. In the mean time what does a bone stock 2.8 make for power... I can't seem to find a reliable figure onlin.

[robertisaar]

i believe the MPFI aluminum head motors made ~130HP and ~175lb/ft with ~8.9:1 compression...

and you could get a 2.8 crank welded and offset ground to get you a LITTLE closer to the displacement limit...

[dskopek]

I ran a 2.8 with ported cast iron heads, solid lifter cam, Elbrock 4 barrel intake,headers and a MSD 6 for spark and it put down 230 HP!!! Sounded like a chain saw from hell at 7000 RPM!!!!!

[SappySE107]

Dyno sheet? 230whp with NA iron heads is beyond impressive.