Turbo Car's HGs Leaking (Fixed with Dyno #'s)

CMac89

Registered User
I went to the track yesterday and had some problems. The first two runs, I ran into a problem with the throttle sticking wide open two runs in a row. Both of which, the motor went to 7700 RPM. I got two somewhat clean passes. One pass, I babied it off of the line and just went through the gears smoothly and it trapped 125mph. The next run, I turned the boost up from 19 to 25 and it did not gain any MPH at all. The next run, it started breaking up and misfiring during the burnout, so I pulled off. I checked the plugs and wires, then made another attempt; misfired again.

On my way home it started to get a little warmer than it usually does. Once I got home, there was coolant laying in the battery box and no pressure in the coolant system. The oil has some murkiness in it. I'm thinking that the heads are lifting. I started to notice coolant on the hood and hood latch area after the throttle stuck open. AFR was 10.80-11.00 the whole run. Timing was at 22* for all runs, too.

I was thinking about o-ringing the heads. I've never dealt with o-ringing, for me personally. I would like to just o-ring the heads, since I don't wanna pull the motor out.

Picture of the oil:
IMAG0246.jpg
 
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That sucks dude. I had my block o ringed way back when, by Coy. When the MLS gaskets came around I wanted to get the wire out of there, but couldn't, so I left it in. The MLS gaskets are on the car now with the o ring wire and holding up well. There is a recess on the gasket at the same diameter as my orings. .030 over bore. But that is prolly on the wrong side of the gasket if you do the heads. Not that it really matters cause it all gets smushed flat when you torque the heads.

Nice MPH tho.:cool:
 
I'm using e85. I've been wondering if it was just detonating. There are 4 cylinders making 850whp with e85, which is why i don't see it detonating. AFR was rich. The HGs aren't blown, they just seem to be pushing some water.
 
don't overlook the obvious----it could be a cracked head as well as gaskets....stranger things have happened ;>) on these heads after they have been ported to the nines.......Dan
 
That sucks balls man!

So you think the head lifted from the rpm or are you saying from boost? I don't think 25 is all that rediculous.

Maybe the head studs loosend up? I would check them and make sure. Or maybe you have a vagina block like my old one and the cylinder wall decided to peace out ha.

Is there a fishing pole in the picture?
 
I'm using e85. I've been wondering if it was just detonating. There are 4 cylinders making 850whp with e85, which is why i don't see it detonating. AFR was rich. The HGs aren't blown, they just seem to be pushing some water.

Once they start leaking, they don't stop, so they might as well be blown.

I'd pull the heads and see what's really going on. Chris Wise fought head gasket sealing issues on his old supercharged car for nearly a year, before finally discovering the deck of the freshly built motor had warped from overheating on the initial start-up.

David
 
Yeaaahhh, it's a fishing pole or six. I'm thinking it happened with boost. There isn't as much cylinder pressure at 7500 RPM as there is at 5000-6000 RPM. 25 PSI should be very doable, so there's a silly problem somewhere. The motor still ran okay, part throttle and idle. I'm very sure it happened at the track and I'm just catching it in its minor stage. I don't know if it's winter or spring blend. Should be spring blend, by now.

David, I have overheated it before the Shootout. It probably got to about 230* before I figured the problem out.

Here's a datalog. I accidentally deleted RPM. I showed Corey, so maybe he still has it with RPM on.
 

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don't overlook the obvious----it could be a cracked head as well as gaskets....stranger things have happened ;>) on these heads after they have been ported to the nines.......Dan

You just may be right, Mr. ThornsTucky. Boost could have hit a thin wall.
 
I tore it apart today and found a few things. Cylinders one and six weren't having very much fun. Cylinder six was leaking passed the gasket into the coolant passages positioned to the right of the cylinder. Cylinder one was leaking passed the top of the cylinder. You can see the torching on each of the gaskets and on the block. The heads are fine and everything was happening on the block side.

Here are pictures:

Driver's side gasket:

IMAG0252.jpg


Cylinder six gasket close-up:

IMAG0251.jpg


Cylinder six:

IMAG0250.jpg


Passenger side head gasket:

IMAG0255.jpg


Cylinder one gasket close-up:

IMAG0256.jpg


Cylinder one:

IMAG0248.jpg
 
I suggest taking the heads to a machine shop with a good straight edge to make sure they are still flat enough. if possible, borrow the straight edge and check the deck. The overheating can distort things and when it cools off it doesn't necessarily cool off flat.

The way too much timing comment is interesting. Is there some indication from the pictures of that, or just simply looking at the logs and experience with these motors, with that boost, and that fuel?
 
I was running 18* from 3000-4000 RPM, 20* from 4000-6000 RPM, and 22* from 6000+ RPM.

That isn't very aggressive, but results are results. I decided to save the money on the dyno and just spend the few dollars it takes to go to the track instead. In the long run, it'll probably cost me more or the same as dyno time to fix.

I've been thinking about getting E98 and making my own E85 by mixing Q16.
 
I was running 18* from 3000-4000 RPM, 20* from 4000-6000 RPM, and 22* from 6000+ RPM.

That isn't very aggressive, but results are results. I decided to save the money on the dyno and just spend the few dollars it takes to go to the track instead. In the long run, it'll probably cost me more or the same as dyno time to fix.

I've been thinking about getting E98 and making my own E85 by mixing Q16.

There is no substitute for dyno tuning. There is no other way to come up under MBT without severe risk to the motor at your level. E85 actually burns faster than gasoline when rich and that means pump gas. 118 octane race gas - no comparison.

That tune was very aggressive. You should have started off 8 deg lower than that and worked your way up. You'll lift heads running too much timing and not enough boost before you'll lift heads running too much boost and not enough timing. Those Honda guys making 850hp are probably running 12 deg advance.

But I'm just guessing and I don't know much about E85.
 
I missed that you were running E85. In that case I highly doubt you had any detonation. Dyno shops which tune E85 and I've talked to, as well as one shop that does E85 conversions for folks have all reported that cars running E85 just don't detonate. You have to tune based on power,

That said, you likely had something else leading to excess cylinder pressure which lifted the head and burned the gasket, leading to the leak. I assume the AFR you reported is based on Stoic being at 14.67 (i.e. gasoline based) in which case the AFR looks fine. probably richer than you need though that richness will speed up combustion. Thinking through it I can see Dave's point, and that jives with what I heard from the E85 shop. You may be running too much advance for your combination and that AFR. Ideally you'll see peak cylinder pressure just a few crankshaft degrees after TDC. You advance and/or retard timing so that peak cylinder pressure occurs right where it can do the most work and push the piston down, rather than fight the piston coming up.

That's where the dyno comes in handy, you start with timing low and work your way up, watching as power peaks, and then stepping back just a bit. Advance your timing too much with Gasoline, you'll usually get detonation from the excess cylinder pressure which makes noise and we are used to being afraid of. With E85, you won't get detonation so you can easily end up timing advanced too far causing cylinder pressures to skyrocket way too early. In stock motors, this usually means broken rods, or busted piston pins/pistons. We know our heads love to lift, so on a built motor, that seems to be what happens.
 
What thermostat you got in that thing or any at all? Was just wondering if running the E85 is keeping the motor cooler or not?
 
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