BrianLG35C

iTrader: (2)

I hear you but what psi were they running. My point is if you have performance/racing heads you can run much lower psi for the same power thus reducing stress on the motor.

Quamen

iTrader: (14)

I think that a large part of what bigbri did was some really trick cooling upgrades that SGP does. I am sure there are a number of little things that can be done to help the coolant flow more easily through the heads for the high horsepower/heat guys.

It would seem that most would agree that the coolant pressure in the passages is the main reason for headlift on our cars. Not necessarily horsepower levels. I'm sure it is a combo of both for some people experiencing it.

Just remember, we have seen some experience head lift at as low as mid 400whp and more towards the mid 500's to low 600's. So I would stray away from the too much hp theory. More along the lines of the tuning and the other modifications to the cooling system. I think between those to areas the chances of headlift can be affected quite a bit.

Weqster

heads dont lift.

We run open deck blocks with alluminium sleeve liners. Sleeves move around, sink and do all sorts of crazy things due to combustion pressures and sidewall loading. The SLIGHTEST movement from a sleeve, need only move 0.001", will breach a headgasket seal and allow combustion gases to seep into the water jackets. This is the reason why ppl block coolant only, and dont mix oil/other signs of headgasket failure.

What can u do to stop sleeves moving? Keep boost pressures in check, keep combustion pressures in check and keep rev's to stock to help reduce sidewall loading. Headstuds will also help keeping the sleeves in postion.

rcdash

iTrader: (18)

Without a single report of someone cracking a built short block (rods, pistons only), where is the evidence to justify the need for sleeves?

(Particularly with the additional problems that *may* occur with sleeve movement!)

Weqster

These days aftermarket ductile iron sleeves can be installed very accuratly and easily with the aid of CNC machines. They provider super reliability without the pitfalls off the allumium. It seems the VQ sleeves arnt nearly as volatile as other open decks out there though.

Whats the cheapest way? Stock sleeves
Whats the most reliable? Aftermarket sleeves unless installed by inexperienced people.
What do you need? It all depends on ur goals.

For 500+ hp, i would personally look at sleeves. But then again, i would (and have) try and push the boundaries without them. That is with engines that are worth alot less though....

bigbri

good guess....that and my special overflow setup...

overZealous1

iTrader: (27)

i just did a custom 3" radiator install with a touch over 3000cfm of electric fans. did the rear cylinder bypass also. think i over did it and now my thermostat will bairily open on the freeway with 85 degree temps outside. wait till the evans coolant goes in. funny thing though, the coolant will run hotter, because it is removing so much more heat from the engine. my overheat days are OVER!!

Sharif@Forged

iTrader: (92)

That's correct. Properly CNC machined and installed Darton sleeves have virtually zero chance of moving around.

t32gzz

iTrader: (1)

I think the argument here is whether they are necessary. Most likely not below a ceratain boost level, not necessarily power level. No one has actually cracked a stock sleeve that I know of and several of us with stock sleeves have torn down the motor. Are the sleeves moving? Maybe. Are the heads flexing? Maybe?

Truth be told, it is all speculation. It seems that SVR Tech's head strengthening mod, upgraded studs and HG's (HKS) will most likely do the trick for those of us in the 16psi and below range. bigbri is running 23psi on stock sleeves. He is the poster boy for why you do not necessarily need sleeves. Spend the $2K to $3K+ on vlaves and headwork and you will make more power with less boost. This will equal less stress and heat on the entire motor, not just the sleeves.

Just my .02.

mraturbo

iTrader: (1)

We have all had this discussion more than once. What I do know is I drive the hell, race the hell, and drift the hell out of my car weekend weekout.

Not sleeved yet immaculately tuned with plenty of attention to cooling, voltage, and a few other fun tricks.

I am perfectly happy with my set-up and plan to build many more for customers in the next few months with the JWT BB700s custom kit we have developed.

Hopefully we have as much luck with the Up and Coming as I have with mine.

Sleeved or Not - Big props to all of us who are 600+ WHP on these cars. It doesn't matter to me this way or that way - IF IT WORKS IT WORKS...

M

Quamen

iTrader: (14)

I am interested to know more about the special coolant overflow that Bigbri has but for some reason I think he is not going to let me in on the secret. I would be interested to know BigBri so if you can tell me maybe send me a PM.

Thanks

Weqster

google open deck vs closed deck and u will learn of the pitfalls 'headlift' was invented by the open deck community trying to explain the constant blown headgaskets.

Even back in 1954, chyrstler noted huge problems with their first open deck blocks due to sleeve ingregity. They designed a special headgasket (inbuilt o-rings, ala HKS) and this helped seal the combustion chambers for longer. they eventually switched back to their sand cast, closed deck blocks for a few more years until they refined the die casting technology. Same heads, studs, gaskets and 2 different bottom ends (closed vs open). One suffered from 'headlift, the othe didnt... Its not speculation!

turismo

iTrader: (33)

Thats what Im trying to find out.