Competition Compression

[ThrottleJockey]

Should I lower my compression or not worry about it? I've got the 24 valve torn down completely ( bad oil cooler) and I am toying with the idea of putting in marine pistons, big cam, and a . 094 or . 110 headgasket. Is this in the ballpark for handling more boost or not? Am I a canidate for O-ringing? I've always wanted to do the "rookie sled pulling thing" at Thunder in Muncie and Arcola, IN. Or should I just leave the pulling to the big fuel monster hp 12 valve smokers?

ANY help would be GREATLY appreciated, Thank You.



Brian

 

[Jim Fulmer]

Brian, don't know were the rest of your truck is at but this is a perfect time to put in fly cut pistons, cam and O-ring it and set the head up how ever you want it, then you just have to work on the top side, can't speak for Mitchell as I don't know there program but Piers or Al at PDR would take good care of you and can/will answer your questions... . user friendly.



Jim

 

[Sled Puller]

With a thicker head gasket and fly cut stock pistons, mines pretty sleepy when it is cold, and almost hard to start.



Marine psitons would make it worse, I think.



Get ahold of Mitchells, as they have tried about every combination, compression ratio under the sun, and can tell you how they act on the street.



Unless you are planning on twins and lots of fuel, I don't see why you would want to drop it anymore.

 

[HVAC]

What About Fueling?

You've left some items under the table so to speak. What do you plan to do regarding fueling. If I were you I wouldn't do any of that stuff, save yur money and leave the pistons and cam stock. If you ever do get the engine fueled up an twin turboed, go for a thicker head gasket. You don't sound like your going to be pulling much anyway. JMO

 

[ThrottleJockey]

Wow! How's that for a star studded cast of replies? Thank you, gentlemen for the advice. I have a Blue Chip FMS,cam, Supermentals and an HT3B turbo to be twinned with the HX-35 16 I already had. I'll leave it alone if need be, you guys are as diversified in your expierience as you are in geographical miles and you all pretty much told me the same thing. Don't gotta beat me over the head!

Thank you very Much!



Brian

 

[Sled Puller]

Twins? Definately O-ring.

I ran those same turbos, housing, originally. It was a rocket right off the line. That combo moderately fueled hit 84# of boost, so plan on a wastegate.

 

[Big_DQ]

twins?

here gene,

how does a H2E and a HX-60 sound for a twin setup, just curious, or how bout a PDR HX-40 and a HX-60?



just wonderin'



Kenny

 

[Sled Puller]

I can only comment on the twins I have run,,but knowing your dad, they sound too SMALL!

 

[Briar Hopper]

Plasma-coated pistons would be good, not necessary but a plus since you've got it torn down anyway. Definitely 0-ring the block, several shops around the country, including us, make a practice of offering o-ring service anytime a head has to come off the engine. Polishing and porting might gain you a little boost and lower EGT's, but not a whole lot. Exchange heads are available from PDR and Enterprise Engine, built to the hilt.

 

[HVAC]

HX60's

Anybody interested in a HX60 send me an email. Got three still in the box.



Like was said, O-ringing will be necessary if you are twinning the engine. Better get a set of studs too.



Dave Mitchell himself told me the ceramic coated pistons didn't hold up and upon inspection after having been run for a while, the ceramic coating was non-existant. Teflon skirts are another thing though. If your twins work you don't need anything beyond the stock pistons from what I can see. We don't seem to have piston problems as a rule.



Don't waste much money on porting, clean the head up yourself and then have the valve job done locally. I don't see any advantage in competition when using a aftermarket cam. Twin turbos will do the job if done correctly. My buddy Richards truck is running a Piers top end pump and only hits 1280* wide open at 86 psi boost. No piston damage happening at that temp



In a nutshell, leave the bottom end alone. It's quite formidible in stock trim. Don't spend much money on the head, pay attention to the turbo system. Run a . 020 or . 030 over gasket to drop the compression. As mentioned above, dropping the compression a lot will make for harder starts and a drop in bottom end power.

 

[Sled Puller]

Re: HX60's

Originally posted by HVAC

and only hits 1280* wide open at 86 psi boost. No piston damage happening at that temp

Better tell him to get more fuel... ... ... ...

 

[HVAC]

Now There Ya Go

People, can you believe how SP is advocating surpassing the 1300* line of piston death??? He would have us ventilate all six pistons for his morbid pleasure. That's just not right!



I ask you, is tar and feathering too cruel a punishment for him??? It's legal in Transylvania where he hides out. I bet some of the Ford camp would be in for such a festivalOo.

 

[Sled Puller]

They'll take 1800... . and then a bit more... .....

Fire is

 

[Johnboy3]

how does a H2E and a HX-60 sound for a twin setup, just curious, or how bout a PDR HX-40 and a HX-60?

Sounds like what's going on my truck.

 

[Sled Puller]

John has just settled it , then.



Those turbos are WAYYYYY too small for Big DQ!!!LOL

 

[HVAC]

1800*

Sled Puller said--



"They'll take 1800... . and then a bit more... ..... "



Yur Arss they will! Gene, been there, done that. A cracked head is not a pretty thing. They will NOT handle that temp without cracking the head. Ask Adam, I bought him one head already. He's on like his third or fourth now. Yeah, the engine will run, however the head will suffer.

 

[CRoth - BD-Power]

Re: 1800*

Originally posted by HVAC

Sled Puller said--



"They'll take 1800... . and then a bit more... ..... "



Yur Arss they will! Gene, been there, done that. A cracked head is not a pretty thing. They will NOT handle that temp without cracking the head. Ask Adam, I bought him one head already. He's on like his third or fourth now. Yeah, the engine will run, however the head will suffer.

Before I chime in are you talking piston crown temperature or EGTs?????



If your talking EGTs, 1800° is for sissy's how about 2050°. Last year at 300 ft mark in the quarter we had already surpassed 1600° with 75psi and the squeeeeeeeze. HVAC your right the head doesn't like it, but no cracks, and pistons are still beautiful. :



If your talking piston crown temperature, damn thats hot. How would you measure that???

 

[Sled Puller]

Really? Hmmmm... ... ...

Are you saying that SPA guage you sold me is less than accurate?



Let me ask you this:



Is 12 seconds on the dragstrip harder on the engine than 12 seconds in front of the sled?:-laf



I think thats a good question, answer carefully, Grasshopper!

 

[HVAC]

Yuk It Up!

I thought I was pretty studly with those high egt's. Not so. Do what you will, but big power and lower egts is where it's at.



Christian, where you still running that twin system that produced 600* discharge temps?

 

[HVAC]

Sludpuller

No opinion on your question. This is about egt and I can tell you without a doubt that high egt will result in cracks in the head. Not an opinion.