Let's build a drag race 8BA engine
- Thread starter HopRod
- Start date
In thinking of this, would a Smith-type "jiggler" head that placed the intake valve over the piston to allow for a higher lift/larger valve in order to get more air into the motor help?
frnkeore
Well-known member
So then, the best way to fill that cylinder, with the port that came with these engines, is to reduce the cubic inch displacement, to get the highest HP per CI.
In a class that has 11 lb per CI, it would make since to reduce the size of the engine or, at least increase it to a minium and get as much compression as possible.
A .030 over 221, 24 stud, would be a 225 with the stock stroke and 217.75 if you offset grind it to 3.625. A 239 would be 243.85 and 235.7 with the 3.625 stroke. With the smaller engines, porting and as much compression as possible, I think you could get 1 HP per CI, or more.
I can't tell you what it might take to get 10/1, or higher C/R on a engine that small but, that means that you can have a car as light as 2398 lb.
Haha. Yes they do. My Smith "jiggler" suggestion was in the spirit of keeping it a flathead.
In all my travels, I only saw one pair of Smith Jigglers and it was at Hershey. It was in the late 90's. If only I had a time machine.
You may be interested to read about Barney Navarro's work with small displacement flatheads. He de-stroked some of his blown engines to fit into different race classes, but I believe he also understood the need to get more air into the motor. Between oxygen injection and blowers, I think Barney was on the right track.
How are you talking to? Why are you being so negative?
I have to keep reminding myself, don't pick on the easy ones.
Haha. Good advice.
petehoovie
Well-known member
Not sure why, but 4-71 seems to work better for the snouts are easier to come by. A 3-71 snout that works for a flathead is like hen's teeth.
petehoovie
Well-known member
frnkeore
Well-known member
Food for though.....
HP costs money but HP per CI, can cost a lot more. HP per CI, is what wins races in class racing.
Now a days, you can easily build a 304 to as much as a 315 CI FH, using the 4.25 cranks. But, because of the little 1.312 ID intake port, each time you go up, in CI, you gain total HP but, loose HP per CI. Even with a blower, you can't get much threw that port. I would bet a Built, N/A 302 SBF will put out more than a blown FH of the same CI.
You gain some on C/R as you increase CI but, you loose breathing ability. For the street, CI helps and blowers help but, you'll never win a class race that way.
The old saying "speed costs money, how fast do you want to go?" will always apply, especially in class racing.
HP costs money but HP per CI, can cost a lot more. HP per CI, is what wins races in class racing.
Now a days, you can easily build a 304 to as much as a 315 CI FH, using the 4.25 cranks. But, because of the little 1.312 ID intake port, each time you go up, in CI, you gain total HP but, loose HP per CI. Even with a blower, you can't get much threw that port. I would bet a Built, N/A 302 SBF will put out more than a blown FH of the same CI.
You gain some on C/R as you increase CI but, you loose breathing ability. For the street, CI helps and blowers help but, you'll never win a class race that way.
The old saying "speed costs money, how fast do you want to go?" will always apply, especially in class racing.