Dome Piston & Head Combos

[Schober Motorsports]

Hey guys,

Been looking around and trying to figure out a good dome piston to use in my 440. Looking to get 13-13.5 to 1 compression. I've been looking at Ross Pistons 99501 and looks to be what I need, but what piston vs head combo do you guys use to get that compression ratio up there? Also I really like those Indy SR heads, they look like they should work with a "stock combustion chamber" type design. Goal is 10.50's with my Coronet. Thanks guys.

 

[69 GTX]

I would pick your head before picking piston. Get something with a 75-78 cc chamber. Trick Flows.

 

[lewtot184]

domes and wedge heads aren't a good mix. usually the dome shrouds the plug and there's a power loss. you shouldn't need 13-13.5:1 to run mid tens. i would look for a trick flow head/flat top piston combo (small chambers).

 

[Cranky]

How much does your car weigh and do you have at least mini tubs in it? I ran a Jahns pop up (similar to the TRW 2295) with 906 heads and had around 11.4. The car was a hair over 3200 and ran high 10.60's. It would do a mid 10.50 with the right tune but it wasn't consistent and was affected a lot by the weather. The compression is nice but it can be done with lower than 13-1. I helped a buddy run a 3500 lb Challenger with a 400 based stroker (499?) with Indy heads and it did a 10.0 first pass off the trailer. Compression on that one was in the 11.5 range. More cubes but heavier car......

 

[Schober Motorsports]

Car has mini tubs and 10.5 slicks. When I weighed it last year with the 8 point cage and a 3/4 full tank 10 gals, it was 3700 lbs. Now I have a 10 point in it, but have a lighter wheel combination so it might be a bit less, but not 100% sure. I would rather over build it and it runs 10.20's than 10.80's. Don't want to set myself up for disappointment! Doing flat tops would be quite a bit easier to do vs finding/having built a dome that matches the combustion chamber.

 

[Cranky]

Flat tops imo, are a better way to go. The Challenger with the Indy heads had flats in it. Man....put that car on a diet lol. When I got my 66 Belvedere 2dr post, it was 3370 and it didn't take all that much work to get it to 2950 and it still had the factory AC on it! Granted, no cage but it did have a glass hood and no front bumper (ah the 50's) and it got some lightening work on parts that were not needed for safety like the rear window mechanisms removed etc....

 

[lewtot184]

4.15 crank, zero deck flat tops, 75cc chambers will get pretty close to 12.5:1.

 

[64 Post]

Since you asked...

Diamond probably still stocks a dome piston profile for the Eddy RPM heads. I still have a set I bought 10 years ago from them waiting to go in a build... :icon_eyes:

 

[SUPERSTOCKRACER]

CP Piston with flat top and a set of indy 440-1. You have a heavy car. Your going to need to make close to 650 to get you there. And not leaving much extra. I'd do a .672 comp roller cam , 13.5 piston and a set of ported 440-1 indy heads

 

[dvw]

I look at compression like this. Cheap horsepower while doing a build. That being said in my mind only 2 ways to do it. Pump gas or 14.5-15.0 to 1. Why go in the middle? Are you building a 440 or a stroker? Obviously bigger builds make gaining compression easier. My 572 is 15-1, flat top with HUGE valve reliefs and Indy -1. You can get 13-1 with a flat top in a +.030" 440 but it would take a huge milling job like mine 58cc. My old car was zero deck, milled unported -1, 670 roller, stock cross ram, 4.10, 10.5x29.5, 9" 5000 coverter, 3450lbs with a 4.150" crank. It would run 10.1-10.2@130. Porting the heads and running a good intake and more gear would get there with a 440, but easier with a crank. With the price of stroker kits you can get a 4.250" crank, rods, pistons, bearings, rings, internally balanced from Ohio Crankshaft for $2K
Doug

 

[Schober Motorsports]

Thanks for all the great info guys, gave me quite a bit to think about. Maybe change my build around a bit.

 

[383man]

4.15 crank, zero deck flat tops, 75cc chambers will get pretty close to 12.5:1.

This is right as I was going to use flattop pistons at zero deck in my 440 stroker and I use the Indy EZ heads with 75 CC chambers and .039 head gaskets. My setup would have been close to 12.0 comp which was not good for me since I was building a pump gas car. So I ended using the D-dish pistons that dropped my comp to 10.6 and it still has good quench since the D-dish piston still has a flat area on it for quench. My 63 weighs just over 3700 lbs and with 10.6 comp on pump running through the full exh system it has run 10.70's. You can get the comp you want using the flattop piston with the D-dish with the 75cc heads which I would do as most feel as I do that the flattop piston setup with quench is better to run then using a pop-up piston. Good luck , Ron

 

[drj72602]

Very very nice car. But I,d like to see when it was built.

 

[drj72602]

Very nice car. But I,d like to see when it was built

 

[Schober Motorsports]

drj72602, This is what the car looked like the day I picked it up 5 years ago.

 

[mmissile]

I look at compression like this. Cheap horsepower while doing a build. That being said in my mind only 2 ways to do it. Pump gas or 14.5-15.0 to 1. Why go in the middle? Doug

This^^^ I build pump-gas engines for my stuff.

 

[IQ52]

500 lb-ft torque 3,500-7,400 rpm

400 block, Ross flat tops, Edelbrock RPM heads, Erson solid roller, 11.7 compression, 91 octane.

RPM...................TQ/HP

3100.................417/246
3500.................503/335
4000.................519/395
4500.................555/476
5000.................586/556
5500.................571/598
6000.................599/684
6100.................604/701
6500.................590/730
7000.................575/767
7400.................538/758

It consistantly made over 770 HP, pull after pull, with a maximum of 787 HP, but this was the only one started as low as 3,100 rpm.

So, I think you can use Ross flat tops and Edelbrock RPM heads

 

[69 GTX]

If your just going to bracket race, use a flat top piston and run pump gas. Save yourself some $ on race gas. Having been a racer in the past I sure got tired of paying big $ for race gas.

Jim just built me a 440 with 9.9:1 pistons and made 590 hp. I'm sure with a different intake & cam in a race car it could make 650-700 easy.

 

[BigHemi]

While I agree 100% that you'd be better off w/ a pump gas stroker, here's what you originally asked for...
440, stock crank, Manley H beam rods, Ross dome pistons, about 14:1
out of the box, std. port, Indy SR heads shaved down to 67 cc to get the compression up
266 at fifty solid roller, Weiand team G, 1050 dominator
727, 5k stall, 4.10 gear, 28x10.5 slick
3700 lb. cuda ran 10.40 at 129.1 mph w/ a not so great 1.49 sixty foot.

 

[dvw]

400 block, Ross flat tops, Edelbrock RPM heads, Erson solid roller, 11.7 compression, 91 octane.

RPM...................TQ/HP

3100.................417/246
3500.................503/335
4000.................519/395
4500.................555/476
5000.................586/556
5500.................571/598
6000.................599/684
6100.................604/701
6500.................590/730
7000.................575/767
7400.................538/758

It consistantly made over 770 HP, pull after pull, with a maximum of 787 HP, but this was the only one started as low as 3,100 rpm.

So, I think you can use Ross flat tops and Edelbrock RPM heads

Numbers look good. How many cubic inch? How does it run in a car?
Doug