domes question

[EZ2FLEE]

I am doing ad engine overhaul after last summers crank failure......that setup ran a noss cool head with 20cc domes, this year I figured I'd go with custom cuts......I went with John at passion because he was doing other work for me anyways....I gave him the setup, ign,oct,pipes,port, the works and I get 23cc custom cuts for same setup, won't this hurt my compression ratio.......not trying to bash in any way.....John is great at what he does .........just trying to get a better understanding....if I'm leaving out needed info lemme know,

[vulvafan537240]

I am doing ad engine overhaul after last summers crank failure......that setup ran a noss cool head with 20cc domes, this year I figured I'd go with custom cuts......I went with John at passion because he was doing other work for me anyways....I gave him the setup, ign,oct,pipes,port, the works and I get 23cc custom cuts for same setup, won't this hurt my compression ratio.......not trying to bash in any way.....John is great at what he does .........just trying to get a better understanding....if I'm leaving out needed info lemme know,

 

What is your setup and elevation?

[EZ2FLEE]

.050 over, +4 timing, t5s, trail port, 93 pump, cooled, br8es plugs, 1200ft

[ClayAiken]

23cc Has a lower compression then 20's it sounds right for your setup. With that elevation i dont know how quick id be to try 21's

[vulvafan537240]

Builders know alot more than the rest of us so I you have a question about the domes id ask him.

[EZ2FLEE]

Dude I know its got lower comp I ran 20cc for a couple years, but these were cut for my setup, didn't know if it would make more power though, tried to ask him but I.can't get ahold of him

[EvilBanshee]

usually the higher the elevation, the more compression you can use, and get away with less octane. I would think you could be able to run 20cc domes easily. Custom cut domes controls FLame speed and squish in the cumbustion chamber. YOu ll have to ask him why he went with such a low compression dome.

[WINDYCITYJOHN400]

The cc of the domes is more than just pick a cc and go. You port timings can effect the motors compression. You may have ran 20 before, but if you were too close to the edge with your running compression or corrected cc's you might have had the crank failure due to mild detonation over time trashing the crank.

The bigger concern is why won't Jim call you back.

[EvilBanshee]

Very true, port timing has a big effect. I didnt know you had him port your cylinders.. I thouight u meant he just re shaped your domes for you, and that was all he did.

[EZ2FLEE]

He did no porting for me, he welded a crank.......

But I gave him the measurement from top of cylinder to top of exaughst port and he had some cut based on that and mods......I haven't run the engine yet so I don't know what its like, I was just.curious as to what kind of power change I might see.....and I run 20cc on same engine for 3 years and a lot of hours, the crank was stock and had connecting rod bearing failure.......the pistons probably would've looked great if it wasnt for shards of bearing and whatever else bouncing around on top

[EvilBanshee]

Give it a try, their is lots of power to be unlocked when you start to play with the dome configuration and squish. You can also kill the power as well if you have no clue what your doing lol. I would give it a try first, if its gutless, Throw a different set of domes in it.