I have a 400 that I am thinking about using for an IMCA modified for 3/8 and 1/2 mile tracks. I have a few base ideas, but don't know much about the 400, so I have no idea if it is possible. It has to be done fairly cheap ( engine claim is under $1000 ). Which is why I want to run this motor, nobody wants them! The engine can be upto 410cid, 750cfm holley running alcohol so compression has to be fairly high around 13:1, to cut cost run a flat tappet cam. My main concern is getting the compression without weakening the heads. If possible run flat top pistons or some with a mild dome, again as cheap as possible. Maximum rpms would be around 7500. I have no idea how much HP to expect from this but it does need to carry it all the way down the straights. Oh, by the way Aussie heads are not an option. Any ideas on how to make it work and the HP it would make? If I could get from 400 to 500 HP that would put in the class of motors being run. If anyone has an info for this I would appreciate it.

 

while the engine math will work, the heads and vavles will not, why, c ause they are banned. most racing bodies ban vavles over 2.02 in size, or outright ban cleveland heads.

 

Remember, I said circle track, you know DIRT, not drag racing. For the rules the only thing is they have to be OEM there is no limit to what you can do to them or the size valve you can run. The only thing banned here is V-6's, it has to be a V-8.

 

I think the biggest problem would be cost. You can't do a cheap "overhaul" right for $1,000 unless you got your own machine shop. You are talking custom forged pistons which will start you off with a $500 bill. Otherwise it sound like a hell of an idea.

Bear Tracks

 

The actual buildup is not until this fall, so I have time to get it worked out. My back up plan is ( don't get sick ) I can get a 400 chevy and put it together. But that is only a last resort. As for cost just a basic buildup I was figuring at least $1500. A 12:1 would work I would just have to run 110 octane racing gas. I don't know if alcohol would want to burn right with a 12:1 CR.

 

O.K. here goes.

To get compression that high you will have to have domed pistons. Look for 351C domes. In the 400 you should get about 1 point or so more than the 351. Check the claimer ads in circle track mags. Used to be common for domed pistons on the cheap in there depending on the rag. Seems that I remember seeing 12-1's somewhere.
On the heads I hear that you can take up to .080 off without too many problems, but then again if you are pushing 500 hp and you detonate you can bend anything.
To get the revs you will have to get better rods. I don't know for sure, but I've heard that extra-long Big Block Chevy rods will fit if you machine the big end the right width and turn down the crank throws to right size. Don't know for sure, but the math works out about right and they look pretty good side by side on the table. Problem is the price, maybe you can find some good used ones that are still straight and have round holes. I've heard of some guys buying aluminum rods, but they present another whole problem.
The crank may be a problem if you wind past 7500 too much. Don't know, but I've been told that 7500 is the peak of what you should push this thing. But aluminum rods would take some of the load off of the crank.
That brings up piston speed. 400 ford has much higher piston speed relative to 400 chevy because of 4.0 inch stroke compared to 3.75 inch stroke.
Heads. There is something not too many people know about with the 400's. In 1969, or 70 there was a 4bbl option on 400 fords. I've only seen one of them in my many,many trips to machine shops and junk-yards. The one I saw, the guy swears it was original. He bought the station wagon brand new from the ford dealer and drove hell out of it. He overheated it and cracked the heads. When he went to replace the heads he found out just how rare this thing was. Rumor has it that these were only produced in the single or low double digit number, so his car was pretty rare. That engine now sits in the corner of his barn, replaced by a 2bbl cause 4bbl heads are so spendy......Moral of the story 4bbl heads were stock on one year of 400's. If the rules would allow you that then you would surely have a stomper.
2bbl heads. Port them if rules allow. Bigger valves if rules allow. if not, then o'h well they still outflow chevy heads by a huge margin.

It wont be cheap, but it will sure be a sleeper. Nobody will believe that a 400 ford will run with the chevy's until you show them.:-staun