I6 in an IMCA?

[Anonymous]

My dad is going to build a dirk track modified and we got to thinking about wieght and how we could drop weight in thew car for handling. I brought up the idea of use a 200 or 250 in it. I'm thinking it will need at least 300 hp so it can keep up with the other cars. It will be running in an engine claimer class so putting 2k in the motor is not prefered. I'm also hoping that it being a I6 it will turn off anyone who would try to claim it. I know that the 6 won't out perform the V8's when it come to $ per hp. The idea is that having about 100 or more pounds less in the front and the entire car will let us zip through the corners a lot faster than the heavy V8's. All coments, suggestions, questions,and ideas are welcome.

 

[WhitePony]

Engine claimer class?

 

[Anonymous]

your gunna need alot more that 300hp if IMCA is anything like Wissota dirt track racing. Most of the Modifieds are running around 450-500hp out the the V8's, The superstocks are in the 350hp range and the late models 600+. There was a guy that ran a 300-6 in the superstock class a long time ago around here, he was pretty competitive with his 300-6 and turned ~6500rpm with that engine on a stock crank/rods and custom pistons (balanced bottom end)

 

[6bangerwanab]

yeah, i would use a 300 and build it how you would a v8, the only problem with the 300 is that there isn't much of a weight break there. altough you might want to find out if you can run a power adder for having 2 liters less than anyone else.

 

[Anonymous]

If I remember right if you make it in the top 3 anyone who didn't can claim your engine for $500. they get the block that includes the internals, heads, intake,and water pump I think thats it. Thats to prevent people that can afford it from putting like 6k in an engine when others can't. At the sanctioned IMCA races I think the average hp is some where near 400. Most of the guys only change the cam, intake, ignition, carb, plus headers. I'm sure that there is a lot of port work going on in the heads but no one is going to addmit to that.

 

[XFlow_Fairlane]

I doubt you could get there short of an imported head. the new alloy SP head would surely get you there with ease....but gonna be $$$ I guess it is all a matter of how copetetive you want to be. I guess you could dump a bumch of money in a motor if you keep yourself out of the top three...


prob the easiest way would be having a bunch of x-flow's sent up and just having a huge stock pile of cores to work from. a cleaned up stock head and a simple valve job and just go big on cam and compression?

when you start talking about building a race car for a weight advantage it is best to go all out...lightest wheels, tires, everything.....only carry the gas you need to finish a race, etc.... if you can shave alot more weight off than just the motor then you will need less horsepower to move just as fast as them....which means less wheel and tire needed....

 

[WhitePony]

OK I say again......Engine claimer class? What's that?

 

[Asa]

OK I say again......Engine claimer class? What's that?

you win/get to a certain position, someone can "claim" your engine and you have to give it to them for X amount of dollars

 

[WhitePony]

Good Lord! Who would ever really want to win then? Unless you have unlimited funds to throw away. Plus then you'd have to start over with a new engine.

Who in the hell thought up THAT system?

 

[Asa]

well, considering everyone in it knows that they could concievably lose their engine for a certain amount, it forces them to focus on other aspects of the race

i know that i didn't explain all of it, but from what i read of this thread that's what i gathered, maybe someone will explain the rest of the rules, and what happens when you lose your engine?

and anyways, don't knock it till you've tried it

 

[6bangerwanab]

actually if you used a small bell 6 so that it wouldn't work in anyone elses car (heck not that many even run ford small blocks), it might be worth dumping some money into. then even if they do buy it you can wait untill they find out that it wont bolt up to anything then you can offer them their money back for your engine

 

[80broncoman]

I cam up with a cam for a guy running a amc I6 years ago when I worked down south. He told me NO One wanted his I6 because of the difference of mounts, trans, and other stuff when replacing a sbc.
He also said it worked for him because of a healthy weight break. See if possably you can move the engine back farther compared to rest of the racers.
It can be made to work :!:

 

[ford6man27]

IMCA rules, the engine setback is measured from the center of the rear end to the back of the block. that puts the 2 extra cylinders in length forward of the V8,which kills any advantage you would gain from running a 6 banger. More weight on the front wheels kills the handling. Some classes of dirt cars measure set back from the center of the front axle to the front sparkplug hole. Big advantage to the 6 cyl cars. I run a 300 in a vintage car [31 model A ] on dirt , works great and is realy fun to drive. the car will usualy outrun at least 1/2 of the 350 and 4oo chevies I run against.
Andy

 

[XFlow_Fairlane]

yeah but I am the bastard that would buy your motor and sell it off on ebay just so you have to build a new one

then again this could be worse for the competetion since you will start learning how to make the same power cheaper each time

 

[xctasy]

I'd like to rebuild a 250 with

1. one nice big direct mount 500 cfm Holley,
2. a set of headers,
3.a 1978 head with 62 cc chambers,
4.a set of HSC 2.3 pistons and 6.00 " 2.5 HSC rods and good rod bolts,
5. and give it a special cam which bleads off the compression and allows over reving.

we have an engine which can get power at 5500 rpm, rev to 6000 rpm. I'd get at least 245 hp at 5500 rpm, perhaps 265 if the right cam is used. If the crank and rods could be treated to hack short bursts to 6500 rpm, then you could get into the 290 hp area just with a 250. Cast pistons don't like 4250 feet per second piston speeds, so a set of forged TRW Chevy 229 or 305 pistons would be a good substitute.

A 250 six provides superior grunt out of corners. It also has a good SBF bolt pattern

Data___________________stock 250 Log
Cylinders_______________6
chamber cc_____________62.0
gasket_________________0.027
deck shortfall (calc)______-0.017
piston cc_______________0.0
piston_________________1.531
top land datum__________0.275
rod___________________ 6.00
journal diameter_________2.124
resultant throw (calc)_____1.955
stroke_________________3.91
deck height_____________9.469
bore___________________3.6800
Cylinder Volume (V)______681.53
Piston Volume (P)________0.0
cc ( C )________________62.0
gasket volume (G)_______4.7
deck volume (D)________-2.96
C/R___________________11.69
Capacity (cc)___________4089.16
CID___________________249.5
L/R____________________1.53

 

[6bangerwanab]

I'd like to rebuild a 250 with

1. one nice big direct mount 500 cfm Holley,
2. a set of headers,
3.a 1978 head with 62 cc chambers,
4.a set of HSC 2.3 pistons and 6.00 " 2.5 HSC rods and good rod bolts,
5. and give it a special cam which bleads off the compression and allows over reving.

we have an engine which can get power at 5500 rpm, rev to 6000 rpm. I'd get at least 245 hp at 5500 rpm, perhaps 265 if the right cam is used. If the crank and rods could be treated to hack short bursts to 6500 rpm, then you could get into the 290 hp area just with a 250. Cast pistons don't like 4250 feet per second piston speeds, so a set of forged TRW Chevy 229 or 305 pistons would be a good substitute.

i like taxi boys idea, just build it to somewhat breath, build it with off the shelf parts (heck, junkyard parts if there good), but invest into the cam, btw, how much is the claimer?

fairlane, now i would know where to look for my engine, besides, where do you think i would look for parts for my next one?

 

[6bangerwanab]

wow, i kinda screwed that last post up.

What do you mean? - Adam.

 

[Anonymous]

Thanx for the info xtaxi; what rods would I use with the TRW Chevy pistons? The HSC 2.3 and 2.5 is the four cylnder that came in the probe and the pistons are forged? Your hp figures are about what I was thinking, I'm also thinking that the amount of torque this motor generates will help make up for the some what lack of hp. We kinda ran into a little snag so far as car wieght goes in the rules it says the car must wiegh a minimum of 2,450 but I think that it only applies to asphalt cars though, I'm going to email them about that. If it has to be that heavy then there isn't really an advantage to using a 250.

 

[xctasy]

The Ford 2.5 HSC was a cut down I6 Ford, and was only found in the Taurus and some of the late 1992 fwd Topaz/Tempo's, me thinks.

The pistons in the 2.5 are not forged, but 305 pistons can be found that are, and its only a 16 thou bore out of the little end wrist/gudgeon pin in the Ford rod, and the Chevy piston drops on.


The 250 is a little heavier than an alloy intake 289 or 302. The option would be to look at a 300, as its physically larger, but there is little weight differencebetween 250 and 300's. Thats because the alloy intake on the 300, and the closed block design of the 250 cancell each other out. The big block side plate I6 engines are very light.

 

[6bangerwanab]

305's are the same size? i thought that they were a bit bigger. under 4", but bigger.