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Anyone Tried 1/2" Head Bolts??

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An engine design having to tolerate detonation with a gasoline/air mixture is a completely different world compared to detonation of a methanol/air mixture. Actually, methanol really doesn't detonate in the way gasoline does. You can have varying intensities of detonation with gasoline. Not so with methanol. A more proper term for a methanol/air mixture that goes into uncontrolled combustion would be preignition. A preignition condition with gasoline would more closely match what happens with a methanol/air mixture when it goes into an autoignition condition.
Preignition compared to simple detonation is a much more intense and destructive form of uncontrolled combustion. Where detonation is understood to occur after the spark plug has initiated combustion of the mixture, preignition occurs at any given time before the spark plug has attempted to initiate the combustion event. It would be like the complete intake charge spontaneously combusting with a very quick flame speed and pressure rise, at a number of crankshaft degrees added to your planned ignition advance. Basically, this causes the cylinder pressure peak to occur much too early and attempts to stop the crankshaft and cause it to turn in the opposite direction of rotation. Obviously, head gaskets, pistons, rods and the crankshaft don't like this much and one or the other will exit the scene, stage right.
This is the main reason why knock sensors are useless with methanol fuel. If the knock sensor goes off, 9 times out of 10, it's too late.

Knock sensors should never be mentioned in a discussion involving the burning of methanol fuel. If one relies on a knock sensor when burning methanol, he will learn real quick not to.

Any form or level of detonation with methanol fuel involved should be avoided at all costs.
 
Great thread! This may sound ignorant & I apologize but if you want to see what will break next then why not just tack weld the heads on? Very primitive but will find the next weakest link!
Good Luck with your project & again very informative for us!

LOL! I actually started typing a post to suggest you go the "Offy" route! Weld the heads to the block and assemble it all from the crankcase. :D:D:D

...thought better of it, though. :D
 
Update!! Its together and almost ready to stick back in the car and test it. First test hopefully in a couple weeks:D. ARP engineering said the ideal torque on these studs is 130 ftlbs:eek:. I admit I was chicken to try that much torque , so I torqued them to 110 and all went well!! Well then after sitting a day and thinking it over I went back and loosened the retorqued them to 120ftlbs:eek:. Then 125 ftlbs:eek:. After sleeping on it overnight I thought this is a test right!! So yesterday I loosened them all up one at a time and retorqued them to the recommended 130 ftlbs:eek::eek::eek:. It worked perfectly!! All studs are at 130 ftlbs!! Lets see what testing shows.
Thanks Mike:cool:
 

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Update. Took the car to the Turbobuick.com nationals last week for its first start-up and test (tracks arent open here yet and I dont start it up here where I live out of respect for my neighbors). Had the typical first of the year start-up pains (had to take the blower off and repair a fuel leak out the back of it the first day. Then went to make some short blast to get a bit of info on computer and the first 2 runs through some curves I wasnt expecting. Bottom line , the first real pass we made was a time shot on Satrday morning and it went 4.35 at 161+ in a bit of a backed down state. Then qualified at I believe a 4.39 and went 4.42 in the final round.

Still need to check everything out , but for now I will say it looks like so far so good with the 1/2" studs. Mike:cool:
 
Bumpity Bump..... for a fresh update....... and a few questions......

How is this setup still working?

Has it seemed to help as much as you first thought?

Any HG failures since install?

At what point (HP level..... or ET level of a regular weight turbo Buick) would you think this mod might become feasable to tackle?
 
Bumpity Bump..... for a fresh update....... and a few questions......

How is this setup still working?

Has it seemed to help as much as you first thought?

Any HG failures since install?

At what point (HP level..... or ET level of a regular weight turbo Buick) would you think this mod might become feasable to tackle?

Well all in all I would give it a thumbs up!! But it has focused the weak link onto the cylinder heads themselves. I can pretty easily go 4.20's in the 660' so that has been an improvement , but I had 2 cylinder head failures which I believe are the direct result of the casting material used in the stage2 heads. I have parked the car for the year and plan to junk the heads I was using as they have been repaired 4 or 5 times , and start with a better set and try to strengthen the deck surface of the heads buy welding the complete deck surface solid except the head bolt holes. Im also going to try to develop a different concept in sealing the heads to the block but that will be another thread!!
As far as a stock block application , since I started this thread I have heard from more than one person that this has been done to 109 blocks in big boost applications:eek: so I would say if your/anyone is to the point where head gaskets are holding back a more aggressive tuneup then it sould be considered as long as you have the bottom end to handle the additional power. Mike:cool:
 
I just read this thread start to finish and wow...At what horsepower level /boost level would this be necessary? Also what was the new head failure you experienced?
 
First pic happened in the spring and was partially happening while it was on its fastest pass ever , cause the next pass it backfired about 1 second into the run. Last 2 pics are from the last failure. I have done this very same thing before , and Barry Kemper with the turbo dragster did exactly the same thing at Bowling Green 2 years ago. If you look closely you can see how thin the casting material is in that area and this needs to be addressed to move forward with more power. The head and gasket in all other areas looks great so Im fairly sure the head material just gave up!! Mike:(
 

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Those head gaskets look like the same type of head gaskets that a top fuel dragster runs..... you know... the 320 MPH in 1000 ft nitro burning top fuel dragsters....

Man that rocks!
 
Mike,

One observation.....apparently this journey started when you were looking for a solution to blowing the gasket between two of the cylinders..... now that the 1/2" studs are installed in the middle two rows...... you blew it towards the outside of one of the end cylinders (1, 5, 2, or 6). With that said....it would seem logical that the next step might be to go 1/2" studs all the way...... for all studs..... if this is possible with your setup. Just a thought.

I'm sure you have considered this already.....
 
Mike,

One observation.....apparently this journey started when you were looking for a solution to blowing the gasket between two of the cylinders..... now that the 1/2" studs are installed in the middle two rows...... you blew it towards the outside of one of the end cylinders (1, 5, 2, or 6). With that said....it would seem logical that the next step might be to go 1/2" studs all the way...... for all studs..... if this is possible with your setup. Just a thought.

I'm sure you have considered this already.....
I was under the impression Mike went with 1/2" with all the studs. If the above is the case, I would have to agree.
 
In the beginning of the post I was considering upgrading only the 2 center rows since that seemed to be where the problem was, between the cylinders. ARP pricing structure made it possible to buy more studs cheaper , so I ended up buying 5 complete sets. Bottom line is they are all 1/2" L19 studs now and the problem between the cylinders seems to be OK. Mike:cool:
 
In the beginning of the post I was considering upgrading only the 2 center rows since that seemed to be where the problem was, between the cylinders. ARP pricing structure made it possible to buy more studs cheaper , so I ended up buying 5 complete sets. Bottom line is they are all 1/2" L19 studs now and the problem between the cylinders seems to be OK. Mike:cool:

Ah.... I knew in the beginning (I actually went back and re-read the beginning of the thread....) that it was only the middle two rows of studs....

Oh well.... just a thought....
 
First pic happened in the spring and was partially happening while it was on its fastest pass ever , cause the next pass it backfired about 1 second into the run. Last 2 pics are from the last failure. I have done this very same thing before , and Barry Kemper with the turbo dragster did exactly the same thing at Bowling Green 2 years ago. If you look closely you can see how thin the casting material is in that area and this needs to be addressed to move forward with more power. The head and gasket in all other areas looks great so Im fairly sure the head material just gave up!! Mike:(

Not the usual blown head gasket. Iron heads next time?

Best of luck on the next incarnation,

Joe
 
Holy blown cylinder head!!!!!!!!!! :eek: Im still wondering at what power level in your opinion would you consider making the switch to 1/2" studs ?
 
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