56er six pack build

[Powerabout]

Yes Fred
On the dyno hit the outside of teh case cylinder walls with your infra red temp gun to ensure all are the same then experiment with controlling the total waterflow to the engine and it will make max HP at a certain temp for sure
Typically OMC race motors dont have thermostats but I think they should especially when you use forged pistons as they need to be running in warm sleeves before you punch it

[Fast Fred]

i would think that to be the part of the basic dyno service, but it's not or so it would seem... anyone can buy a dyno and make claims. any ways i build modas for the fun of it, and cuzz i can and or know how. so not hearin any words on the long rod 56er pistons so just goin to gets some wisecos, i can do my own finger ports, gots some port hights to share, check them against the SST60, and Mod50 hights i have

[camohunter]

the gain in mechanical leverage is not enuff to out way the cost, it's minimal, been a wiseco dealer for about 25years now. there is not a big dif' in the mod 50 rod over the 56er

So the wrist pin hole in the mod 50 piston is closer to the top to allow the longer rod? OR does it extend past the deck into the cylinder head? I'm new at this trying to learn how to build a motor.

Justin

[Fast Fred]

the wrist pin is moved closer to the crown (top), the crown at TDC is about the same as stock give or take. so exhaust hight measurement on SST60 we go from the top, 1.485, mod50 is about the same. on the chamfer from the top on sst60 it measures 1.393, on the mod50 it comes out 1.330. i'll take some shots, so you can see how i get there.............

[Powerabout]

If you have different length rods you cant compare port height you need to compare opening crankangle degree.
Btw a longer rod has less mechanical advantage
It increases piston dwell time at tdc and bdc
It reduces side load on the piston
It reduces max piston speed by slowing the accelaration

[Fast Fred]

ya, all them is true, my self. i'm thinkin we just see it diferant, short rods are quick to spin up, the long rods be pullin in at the end of straight away.

[Fast Fred]

so, Powerabout gots some good points, temp bein vary important, if not up to temp, when you lift and then slam it, she will just fall on her face. i am seein a deg wheel needed on the intake side, need them to be set so finger ports are timed right. both specs are given, work in your deck height ( its there , need to be clipped) want to stay safe, stay on the sst spec, , think in the middle be better, or you can take it all the way, your choice.

[Fast Fred]

the wheel............ it can be help full, it can also be confusin and frustrating, but just in case there is some thing to be seen, we'll have a look to see what slowin the piston speed down does..........................i'm sure there is someone out there who knows, be good to hear from ya ...............

[Fast Fred]

so i gots to pull a crank, so went over and over on rod length, and it was thought best not to push exhaust height more than .040 over sst60 spec, so not to pull all the low end out but some blow down time should be added, added bore size would make up for it. sst 60 spec on intake is 118deg atdc on the side transfer ports and 120deg atdc for the boost, i am movin the boost port timin up closer to 118deg. finger ports open at 118deg..................... i'll get back when i pull this crank

[Fast Fred]

blow down is the time when the exhaust opens but before the intakes opens, the cyl dumps off the power charge to a level that the intake charge can push its way in.