572scarab

Has anybody ran high compression reguarly! I have a 572 and am looking at around 13 /1. I understand i need to run racing fuel, But is this a reliable set up

KAAMA

Wette Vette is OSO's naturally aspirated HIGH COMPRESSION KING!!! Sit tight, he will see your thread and jump in here to help you so fast he will look like a hungry trout chasing a worm!

formula31

Does the word "hang grenade" sound familiar. Never done it myself but I have a friend who regularily blew up high compression engines in his boat. Takes all the best parts and then its a crap shoot. And what ae you gonna do when you want to go on a poker run, have drums of racing fuel waiting for you in places and a siphon hose? You are better off putting blower on it. Just my opinion of course. Best of Luck.

572scarab

Most of my time(all of my time) is spent at one lake where i have my own dock fuels not a problem

WETTE VETTE

You're killing me KAAMA! I do run a high compression (13.2:1) BBC and in my opinion it is very reliable. I have yet to have a problem with about 75 HRS logged on 6000 plus RPM high compression engines. The key to making a high compression motor live is fuel (I run 110 octane leaded Union 76) and cam selection. The fuel is pretty obvious, but the cam takes some real expertise to make reliable high compression HP in a marine engine. I can't give you cam numbers since your combo is quite a bit different than mine, but I can offer some assistance. My motor is a 498" Chevy with fully ported 325 Pro 1 heads. The cam is a comp grind with 272/280 duration at .050" with .714" gross lift on a 112 + 4 installation. It seems if you keep your net lift at .700 or less with durations @ .050" in the high 270 on intake to mid 280 on exhaust you can expect to get 75 hrs. out of springs and lifters. You will need springs that come in at 225 to 240 on the seat installed at about 2". Isky makes a good spring and I am running comp 951 springs. High compression ratios are designed to give big cams enough cylinder pressure to continue to run at low RPM with some efficiency. High compression with to small of cam on the wrong LSA is a detonation failure waiting to happen. (I suspect this is what happened to Formula 31's buddy) Cylinder pressure control is the key!!!! Shoot for 180 to 200 PSI. Less than 180 will be a little sluggins and not idle well and more than 200 will tend to get into detonation easlily.
It works and is initially cheaper than the blower route. But in the long run the blower will let you do more boating and on pump gas. High compression isn't for everyone!!
Good luck- Hope this helps.

572scarab

thanks for your input sounds to me like you have be there done that. What kind of power in your opinion do you think it sould make? lunati crank oliver rods dart grumppy jenkins heads310cc dart intake 1050dominator Thanks this really helps. any one else out there done this!!!!

WETTE VETTE

With the right combo, you should be able to get 800 to 850 HP out of a 13:1 572!! With the right combo is the key!!

jdnca1

second Wette Vette's comments..Only thing I'll add is "OR MORE"

ps..I think that motor is going to want more head....

bobby daniels

VETTE SOUNDS LIKE YOU NEED SPRING OILERS AND COATED SPRINGS IT REALLY MAKES THEM LIVE . I RUN THEM ON EVERTHING WE BUILD WITH 650 PLUS LIFT AND IT DOUBLES THE HOURS ,THE CAM YOU DISCRIBE SOUNDS PERFECT ,BLEEDS OF ENOUGH CYLINDER PRESSURE AND WITH KILLER GAS SHOULD BE A TERROR,HAVE A GOOD ONE

572scarab

IS there a good starting point for a cam that you might recommend for this app.