dome pistons in 240-300

[john-dickjr]

i know a 351w piston fit a 300 ford, is there any issues when using a 351w piston with a dome, like the angle of the piston domed compared to the valve angle, thinking that maybe the valve will fit the piston

 

[Lazy JW]

There is a lot of room in the 300 chamber, so at least SOME dome would fit. As always, it is important to measure carefully and double-check your work.
Have fun,
Joe

 

[john-dickjr]

There is a lot of room in the 300 chamber, so at least SOME dome would fit. As always, it is important to measure carefully and double-check your work.
Have fun,
Joe

i ordered some 351w pistons with a .210 dome..or 5cc

 

[MICROMACHINE72]

That is what I'm using in my budget 240 build, an old-new set of std. bore speed-pro 351W pistons, lightened, gas ported, cut the dome back from 20deg to 12deg. fits the chamber well. 0.00 deck height, cyl. head cut down to around 62cc looking around 12.1 cr.

 

[CNC-Dude]

Thats still pretty low compression for an engine that small that needs to be pushing almost 2hp/ci.

 

[MICROMACHINE72]

How much meat do you think is on the head deck? I could mill down to around 55cc and get it up to around 13.1 or a little better. Don't know how long the stock 5.4 mod rods are going to hang around though with cr. sneaking up there! I helped a buddy that runs them in a blown- only 10psi mod motor making an easy 550hp to the tires, he gets a season or so out of them, figured it was worth a try at $125 per set. I imagine they must be stronger than the stock 240 rod, but than again the 240 rod is a pretty beefy piece! If this combo works well, ICON makes a nice lite 351w dome, and I'll go with some 5.4 Eagle H-beams next go around, they are still only like $450 per set. Alumn. rods- Bill Miller or GRP can't see $1k for 8 rods. I'll whittle some out on my Hurco before I spend that!

 

[CNC-Dude]

Stepping up into the ranks of Comp class racing bring a lot more challenges and costs than many realize that are used to bracket racing on a budget for sure. Back in 1986, just our cylinder head alone had a $5000 price tag. Now adjust for 2014 inflation and who knows what the adjusted cost would be comparable to. You definately have a steep hill ahead of you, even to meet your expected goal.
Not sure what the deck thickness is on the head. We started off by filling ours because you ended up into the water in so many places porting it, this just became standard procedure.

 

[MICROMACHINE72]

Never bracket raced.. Not my thing, and nothing against those that love it, I would just rather do something else if that's all that was. Took about 10-yrs off to mess with a race boat, before that we ran BB/A Blown gas in Comp. Before that ran with supercharged outlaws, and before that heads up door cars. I realize what it would cost to be competitive comp, but that is not the formal goal. There is so much techo. out there now, and so much money to be spent, and people that have it, that will spend it, I would not dream of spending 5k on a bare head even if I could. Now wasting my time to whittle one out on my VMC if need be?? Well that's another story..

 

[THE FRENCHTOWN FLYER]

... Now wasting my time to whittle one out on my VMC if need be?? Well that's another story..

That's not legal in the Comp Econo classes. Unless, as CNC alluded to - fill up the entire head and whittle away what you need in terms of ports and chambers.

Hint, hint.

 

[chessterd5]

why is it illegal? Please forgive my stupidity I've never raced before. What do you "fill it" with & how? thank you.

 

[CNC-Dude]

The FTF is just meaning that a homemade or billet head isn't legal for competition as per the NHRA class rules for that particular class. As far as "filling" the head, it is common to pour a non-shrinking grout or an epoxy mixture into the water jacket of the head in preparation for extensive porting where you are likely to break into the water jacket. Thus, your fixing the leak before you make it. We had to use the stock production cylinder head in the D/D class of Comp, and because it was so massively ported the ports and chambers had to be brazed up some much, it would leak if we didn't fill them. The block was also filled to within a couple of inches of the deck.