Fastest928

I am trying to understand why stock engines being boosted to 8-12 lbs manifold pressure do not suffer significant headgasket failures, regardless of new or old gaskets and I want to know if anyone has any of the following data:

1 at 8 lbs of boost, how many head gakets failed, how many miles between failures and with or without intercoolers, CR, what ocatane was used, if failed was it due to detonation

2 at 10 lbs of boost, how many head gakets failed, how many miles between failures and with or without intercoolers, CR, what ocatane was used, if failed was it due to detonation

3 at 12 lbs of boost, how many head gakets failed, how many miles between failures and with or without intercoolers, CR, what octane was used, if failed was it due to detonation

And have any aftermarket "lubbrock" or other head gaskets failed and under what conditions?

I am doing some research on bmep and head gasket failures, and need some hardcore data to verify or deny reliability before I move forward.

I am looking for honest data, and if anyone needs to turn this into a plssing match, go elsewhere.


Marc
DEVEK

jon928se

Marc

Is there sufficient data out there in the 928 world ? It seems from my observations that there are not a lot of blown 928s around, maybe 30 or 40 worldwide ?

I know I live in the UK where they may be 1 - yet to see it.

I would love this thread to explode with hundreds of replies saying yes do this and don't do that, but will it?

Prove me wrong

Jon
boring old SE (second SE or CS built)

Old & New

Marc,

I've only got a couple thousand miles on it at 8-9 psi, but I'll let you know when it blows!

Now that I'm comfortable with the system and it has been reliable, I'll be going up a pound or two this spring, to my target boost of 10-11.

Lagavulin

It's infectuous, isn't it?

SilverSFR

Mark,
7 lbs, 32k miles, no gasket failure(yet). no intercooler. 9.5:1? using the best gas I can find.

SilverSFR

Old & New

Let's just say that 10psi gives me a warm fuzzy feeling.

SteveM928

Marc,

As was stated earlier, there might not really be enough data available yet on boosted 928s to draw definite conclusions from. Maybe ask some of the 944 turbo guys too? I know that there are some relavent differences between those engines and the 928 engines, but it might be worth checking with them too.

Tony

We have a much more refined motor than the FORD 4.6 -5.0 crowd. Perhaps Im stating old news and I know from an engineering standpoint its probably apples and oranges but browse the forums there as well. See what head gaskets they are running? Studs or Bolts? They are well into the 500-600Hp level from boosted 4.6-5.0L's. ..Next level of FordGT is to be 550Hp and "screwed twice" also. (aka Twin screwed)

I know it could be an expensive proposition Marc but have you thought about boosting your NA 500Hp motor? Run an Intercooled plenum to "Marge" and give her a blow Perhaps,you could then call your new motor "Homer"...uh...well, for obvious reasons DOH!!!
You already have a BART in the bay area so that name is taken.




Hmmm...BTW, any one done a ford 5.0 /928 swap <ducking for cover>

mspiegle

You mean't putting a 928 motor into a ford, right?


I'm with SteveM928 on this one.

Jim bailey - 928 International

Tony most of the old Ford hotrods have Chev engines , never heard of a Ford in a 928

bcdavis

Jim bailey - 928 International

BC .......note that the Banks small block twin turbo street chev comes in three configurations .... 800 HP , 1,200 HP or 1,600 HP perhaps it is a good thing that they probably do NOT read the 928 Forum Does look like a water intercooler however But Banks always did a lot of boat engines and cold water is free .....

bcdavis

They'd probably be laughing at us arguing about aprox. 100 horsepower differences in our turbo, SC, and stroked motors...

shaaark89

mark,
the tilo car had a head gasket failure several years ago before i bought it. according to my mechanic who rebuilt it at that time, it was due to detonation in cylinder #6. ended up scoring the block, so it was rebuilt with a new block.
as far as i know it was running 8 or so lbs boost, no intercooler and on 100 octane. there were some fuel delivery issues at that time as well which have since been rectified.
as far as mileage, it was on the original motor that was built for the car by pantera motorworks in california so i don't know how many. the odometer doesn't work anyway. suffice it to say it was a few years after being built.
cr was stock as far as i know.

Jim bailey - 928 International

BC you think so ? when a 410 (6.8 liter)chev sprint car engine normally aspirated makes over 800 HP , Nascar 5.9 liter is over 800 HP with a single 4 barrel carb , 4.3 Ferrari V-8 street engine spins nearly 9,000 RPM bone stock .............. if blowing a 5 liter 928 just does as well as the Mitsubishi Evo 2 liter 271 hp in stock trim that is 675 HP ! Some how I do not think we are on the cutting edge of innovation more like simply trying to catch up . Borrowing some ideas from others who went down this same path many years ago .