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Discussion Starter · #1 ·
I just got back from letting Bob Norwood Dyno my car. The motor pulled great however on two of the last four pulls, nearly a cup of water shot out of the radiator over fill bottle. My max HP number did not ever change for these last pulls, but the torque did drop a little each time (maybe, due to the increased water temp). My water temp never saw over 193 degrees.

Bob said this belching was normal because of the high cylinder pressures at 7,700 rpm with 23# of boost. He told me to re-torque the heads and all should be well. Hmm... He never offered to make another Dyno pull after we discovered the belched water the second time. He told me to go home and tighten up the head studs and change the spark plugs.

I’m thinking a head gasket blew and the only thing to fix it is to change out the gasket.

What do you guys think?
 

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Turbobrooks
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I had something similar to this happen and it was a blown headgasket... it only did it at high rpms/boost levels. The gasket would reseal everytime that the boost dropped. Eventually it got bad enough that it blew a path from the combustion chamber to the water jacket and I would see bubbles in the overflow.
 

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Rolling with the homies
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7,700 rpm with 23# of boost :eek: :eek: Damn!

Is this the first time you've had a chance to dyno it since you buttoned everything up together for FFW?
 

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The original
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<-- bsharer

John, you probbably guessed right. You got some boost by the fire ring on the gasket and it went to the nearest water port. If you tear it down, you might have some deterioration of the gasket surface leading up to the water jacket hole, and a slight discoloration on the fire ring. I would try the re-torque first, along with dropping boost 2-3#'s and creap up on it if its fine. I assume you have head studs? (Duh!)

And I would also retorque the intake. Did you use RTV on both sides of the intake gaskets around the water ports? And did you cut out the little "L" that protrudes into the water ports? Ive seen lots of intake gaskets shift when the water breaks down the "L", and it sucks the post of the gasket from #1 or #4, #5, #8 into the water jacket in the head just enough to leak boost into the cooling system.

You probabbly knew all this anyways.

Last pass I had two weeks ago spit some coolant out my overflow too... didn't do it at 21#... but it did at 26# at 6000 rpm :D Dragradialstang said he used some headgaskets (Detroit maybe?????) and he had to use a PRY BAR to get the heads off the block when he tore it down :eek: Im gonna give him a hallar and try those next time! PM him if you are interested...

And... WHAT DID IT DYNO?! Send me a PM if you dont want it posted ;)
 

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Discussion Starter · #7 ·
evil jose said:
7,700 rpm with 23# of boost :eek: :eek: Damn!

Is this the first time you've had a chance to dyno it since you buttoned everything up together for FFW?
Yes, this is the first time at a Dyno since my car has been buttoned up. Prior to that I've been at DMP. Mike M. had been doing a great job on the dyno, but I had repetitive problems with different MAF meters. It was Pro-M's fault with the meters.

I’ve had my car at Redline several times and have been hacking away at the EPEC to try and improve the tune. But with poor traction you cannot get an "true" Data Log.

I recently purchased some MoTeC components from Bob and that’s when he offered to Dyno my car at a discount. So I took him up on his offer.

After a few dyno pulls, Bob showed me the motor’s HP was still climbing at 7,400 rpm. Before today I’ve never had the motor above 7,500. So, I raised the EPEC’s RPM limit from 7,400 to 8,000 to see what would happen on the next Dyno pull. At 7,700 the water was pushed out of the radiator, and thats when I waved at Bob to let off. I gained 23 HP and lost 17 lbs of torque with this extra rpm and the NOVI was at 68,000 rpm. Ouch!!!
 

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Discussion Starter · #8 · (Edited)
Carrie said:
<-- bsharer

John, you probbably guessed right. You got some boost by the fire ring on the gasket and it went to the nearest water port. If you tear it down, you might have some deterioration of the gasket surface leading up to the water jacket hole, and a slight discoloration on the fire ring. I would try the re-torque first, along with dropping boost 2-3#'s and creap up on it if its fine. I assume you have head studs? (Duh!)

And I would also retorque the intake. Did you use RTV on both sides of the intake gaskets around the water ports? And did you cut out the little "L" that protrudes into the water ports? Ive seen lots of intake gaskets shift when the water breaks down the "L", and it sucks the post of the gasket from #1 or #4, #5, #8 into the water jacket in the head just enough to leak boost into the cooling system.

You probabbly knew all this anyways.

Last pass I had two weeks ago spit some coolant out my overflow too... didn't do it at 21#... but it did at 26# at 6000 rpm :D Dragradialstang said he used some headgaskets (Detroit maybe?????) and he had to use a PRY BAR to get the heads off the block when he tore it down :eek: Im gonna give him a hallar and try those next time! PM him if you are interested...

And... WHAT DID IT DYNO?! Send me a PM if you dont want it posted ;)
Thanks for the reply.

I called Keith Craft at home and told him what happened at the dyno. He said that if the motor did not overheat, then something had to push the water out of the radiator. That something would be pressure from the Intake or pressure from a cylinder’s compression.

He mentioned that if it was an intake leak, the supercharger’s boost and the motor’s HP would have fallen drastically when the leak occurred. The boost did not fall off.

I was told that I could retorque the heads down but once the seal has been broken… it’s broken. I may get by with a few more passes but it will leak again, and that’s were it gets dangerous. He warned me that the coolant could leak back into the cylinder during a cool down period. If that did happened, then that cylinder would go hydraulic the next time the motor was started. A cylinder that goes hydraulic will bend/break that cylinder’s rod and or piston. Also, if water is left in a cylinder over night, it will rust up the cylinder.

After, talking to Keith Craft, I’m installing new head gaskets.

Bob calculated that I made 983.78 HP and 808 TQ at the flywheel and he feels that we could get closer to the 1,000 mark if I install a MoTeC module. $$$ :eek: I doubt there’s any more HP to make because the NOVI is way beyond it's rated max rpm. I'm staying with my "paid" EPEC. :D
 

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Turbobrooks
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superpro said:

Bob calculated that I made 983.78 HP and 808 TQ at the flywheel and he feels that we could get closer to the 1,000 mark if I install a MoTeC module. $$$ :eek: I doubt there’s any more HP to make because the NOVI is way beyond it's rated max rpm. I'm staying with my "paid" EPEC. :D
Sounds good! Do you have a lockup converter with your powerglide?
 
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