This is the grudge engine I have been trying to get built over this year and a half.

It’s Hughes’ 360 base 426 stroker kit which in my case will effectively have 14.2:1 CR. However, I now need to drop that to 10:1 or so for pump gas. Yes, I called Hughes to see what they could do about different pistons but let’s just say I want to explore other options

I have trick flow heads which are 60 cc chamber

I’m open to suggestions

Thanks !

whats the top of the piston look like? you can have a machine shop, cut a pocket into the top of the pistons. if the tops are thick enough, or you can you use a thicker cometic head gasket. might mess up your quench but would lower the compression

Piston top is flat.
I asked the builder if he could mill the pistons and he said no but haven’t considered a pocket

Do you want to fix it correctly or hob gobble it up?
Way better to switch the pistons and have it rebalanced in my opinion

One choice. Another set of pistons. You can buy a lot of race gas for the cost of a set of custom pistons. How much street use is it going to get?
Doug

Best bet

I thought thats all there kit came with was the step dish pistons

Choice, flat top or dish.

How do you get 14-1 ? I used a compression calculator and looks like your about 12.5.
You can forget about quench and use a .125 cometic like previously mentioned and you’ll end up with about 10.25

https://diamondracing.net/p-10-compression-calculator.html

New pistons is the only decent solution. To reach 14 to 1 i bet there is a dome on your pistons?. Get the weight of the pistons you now have and see 2hat can be had that is close. If the lower compression pistons are lighter, maybe some heavier piston pins would get you close, or vise versa.

Do you have access to E85? If so switch, you'll love it
My S/P bracket 15.2 to 1 compression motor did

If it is really 12.5: 1 like mentioned above i'd just drive it. Lots of people use pump gas these days at higher compression, especially with large camshafts.

If you just want to put it around on the street you can use pump gas if you keep the load down even with the 14:1. Lots of drag week cars are super high compression but they go down the road on pump gas just fine.

thick head gasket, done all the time with no ill effects. You better check your calculation first though.

If that is a flattop piston deal, at 60 cc head,you are very likely around 12.4-12.5 compression. Not sure where you are coming up with over 14 to 1. That would take a dome piston with 60 cc heads.
As mentioned, you can run a custom thicker cosmetic gasket to lower compression a good bit.

Have you considered E-85. For years we didn’t have it locally but now our Sheetz stations have it.

My dyslexia kicked in on the original post
I meant it was going to be 12.4 : 1

my bad

It will ONLY see street time and honestly it probably won't get driven too much. I am not opposed to running race gas but if I can avoid it, I will

Thanks guys - all good info!

I agree that 14:1 sounds a bit high for a flat top, my 414 is 11.57 with a >64 cc chamber, I can see 12.5-12.7 but not 14. You can prolly relieve the chambers and flycut 8-10 ccs out of the pistons with a D dish but by the time you pay the labor you're better off with a new slug weight matched (if possible to what you have.

is it a mopar pin of SBC? I run an ICON SBC race piston in my 440 W2 (4.06 x 4.25 with a 6.200 rod) because I only wanted a 10:1 street motor. I have a 10:1 426" Ford windsor stroker (same bore & stoke as yours) in my cobra replica, it has a D dish piston too.

I don't know what your cam is like but I would certainly be conservative on timing and try it out on pump. If it isn't driven often I am not sure I would run E85 but I have no experience with it.

Cam is Howards solid roller 277/285 .600/.600

That’s a TON of duration for your compression and small heads. Way more than I would run, even in a very racy combo with those heads