Need help with information for actual race vehicle

[sureshot007]

I'm the other idiot racing this truck, so let me say Hi

The rules say the block must be "based" off a block available in any car by the manufacturer, so we could do a dart block or something...if only I had the money....

My intention was to have something as close to off-the-shelf as possible. I really don't want to get involved with grinding the crank at all. 175+hp would be perfect. And it needs to be somewhat rev happy. Oh, and we are on a budget, since this racing stuff is expensive! If anyone can point us in the direction of used parts, all the better.

So the laundry list right now is:
2.8 long block
3400 heads and complete intake
'7727 ecm with complete wiring harness
cam
22lb injectors

Would there be significant benefit from upgrading anything in the heads? Throttle body?

[sureshot007]

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!!!!!

I'm curious about this setup too...

[dskopek]

I still have most of that setup in the garage. I think all I am missing is the crank(Spun #4 rod bearing) I also think I have the dyno sheet from this motor yet. If I can find it I will scan it and post it. I will check and see if Petit's kept a record of it when we ran it also.

[Superdave]

3.4 camaro engine with a 2.8 crank, (3028cc) + a 3500 top end and a cam = serious power

If you use the 3.4's pistons they'll sit below deck .1095, you could probably have the deck shaved and the heads shaved to get the compression back up in the mid 9's.

[666Racing]

I run an NA iron head 2.8L. I adapted a holley 500 cfm 2 barrel to a TBI manifold (alot of work!). crane roller rockers & studs, big crower solid cam (248Int. @ .050), machined heads to fit smallblock chevy springs, retainers & seals, crane CD rev limiter ignition (set at 7500 rpm w/stock resized rods!) , 1.5" long tube headers w/ 2.5" collectors, 3" exhaust. This combination has run dozens of WOT side-step launches at 7500 rpm at a local hill climb event and over 80K merciless 4-season street miles to boot with no failures whatsoever. I have run Koo-Koo juice cocktail - VP C-12 race fuel with 20% nitro-propane, 15% propylene oxide and a locked out distributer set to 40 degrees. I just can't seem to kill the little beast!

[geoffinbc]

You can get .040" over pistons for your 2.8L and get a 2899cc a little bigger but you don't need custom pistons. RWD pistons will start off with 8.9:1 compression with iron heads to get you started and when you have the time and budget you can change to aluminum heads and get 11:1 compression and make more power. But like you said your on a time and money budget so start with whats quick and cheep. If you win some then spend more money. But don't jump in with 3500 heads, Fuel injection and custom headers because you going to run out of time and money real quick and it has rarely been done in a RWD vehicle so nothing is proven in your racing application.

[pocket-rocket]

A little birdy told me you needed some diagrams.

86 Comanche RWD 2.5 w/ feedback carb ECM connections:


86 Comanche RWD 2.5 w/ fuel injection (4 parts)

[sureshot007]

So is the consensus that we swap to MPFI or carb?

[666Racing]

Tuning a big cam with MPFI is not easy and the long runners won't make high RPM power. The Edelbrock manifold sucks for high RPM power because 3 of the ports are half sized to boost torque (it can be welded and ported full size- a lot of work). A holley 500 cfm 2 barrel can be mounted on a modified carb manifold or a modified TBI manifold-no easy way out here either. 11:1 + compression with iron heads is not possible without custom dome-tops (GM used to offer forged 12:1 2.8L pistons but no more) The Chevrolet High Performance Bible says an iron head V6/60 is capable of 1.5HP per cubic inch - 173 x 1.5=259.5HP! I think you will need to figure out what RPM range the truck will see on the race course and cam and manifold accordingly. My combo (stock shortblock, holley 500 cfm on a TBI, huge cam) really wakes up at 3500rpm and pulls hard through 7200rpm.

[ssdurango]

I run an NA iron head 2.8L. I adapted a holley 500 cfm 2 barrel to a TBI manifold (alot of work!). crane roller rockers & studs, big crower solid cam (248Int. @ .050), machined heads to fit smallblock chevy springs, retainers & seals, crane CD rev limiter ignition (set at 7500 rpm w/stock resized rods!) , 1.5" long tube headers w/ 2.5" collectors, 3" exhaust. This combination has run dozens of WOT side-step launches at 7500 rpm at a local hill climb event and over 80K merciless 4-season street miles to boot with no failures whatsoever. I have run Koo-Koo juice cocktail - VP C-12 race fuel with 20% nitro-propane, 15% propylene oxide and a locked out distributer set to 40 degrees. I just can't seem to kill the little beast!

Whoa! Can you send me more pics of that truck and engine??

[666Racing]

...will do...

[dskopek]

Tuning a big cam with MPFI is not easy and the long runners won't make high RPM power. The Edelbrock manifold sucks for high RPM power because 3 of the ports are half sized to boost torque (it can be welded and ported full size- a lot of work). A holley 500 cfm 2 barrel can be mounted on a modified carb manifold or a modified TBI manifold-no easy way out here either. 11:1 + compression with iron heads is not possible without custom dome-tops (GM used to offer forged 12:1 2.8L pistons but no more) The Chevrolet High Performance Bible says an iron head V6/60 is capable of 1.5HP per cubic inch - 173 x 1.5=259.5HP! I think you will need to figure out what RPM range the truck will see on the race course and cam and manifold accordingly. My combo (stock shortblock, holley 500 cfm on a TBI, huge cam) really wakes up at 3500rpm and pulls hard through 7200rpm.

Sounds like we ran about the same cams, mine was crower also but i think it was about 236 Deg intake and about 240 deg exhaust at .050. You are right about the manifold having 3 smaller ports, did not have to weld them but spent time with a carbide and used the 4 barrel top hat. I used Ross flat tops with zero deck and had about 10.4:1 comp. It had NO bottom end power but it pulled hard up top until it bumped the rev limiter.

[666Racing]

Holley 500cfm 2 barrel on a modified TBI intake

[666Racing]

...pics too big ?...

[TeamHazardRally]

so there are conflicting stories now, will the RWD block and pistons work with FWD heads to make 11.1 CR or not. A couple of you have said yes and one has said NO. I'm not saying anyone is right or wrong because I sure as hell don't know the answer to that one, has anyone done this? What info is there to back up either setup.
So it looks like the race in June is going to be on the AMC time machine... you know... it's so slow it feels like its going back in time.... (I said two coats of wax McFly) so maybe, MAYBE We'll have a stock engine in for the July race in Maine. Either way I really look forward to taking all of this info and putting it together into something that doesn't suck over the winter. We have some good machine shop resources, Fabrication Resources,engine builder resources, ... and hopefully parts resources (it would be awesome if some vendors on here would be willing to help us out for advertisings spots on the truck). But either way we apprecieate all of the input from here, keep it coming. On a side note, does anyone offer black exhaust manifold flanges to make your own exhaust manifolds from?