1/2" Head Studs in a 109 Block ..Who's Done It?
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http://www.turbobuick.com/forums/engine-tech/363412-popped-head-gasket-2.html#post2903437 call this guy or pm him he runs 1/2 inch head bolts. mtturbo87
x2..
We done it back in the Buick days and can say it DOES make a huge difference.
Head gasket issues are two fold issue, main issue is the bolt strength. The other issue is lower deck deflection in the head, typically this is the lesser of the two issues.
Now that we started to play with Mustangs they have a similar problem when you push a certain HP level, specially seeing our blocks don't have the extra head bolts like a Stage II motor. That is why we always increase the size of the head bolts and look for an aftermarket head that has the thickest lower deck. These two tricks with Cometic gaskets is a great solution, in fact since we made this change we never had another head gasket issue with a Buick or Mustang.
Head gasket issues are two fold issue, main issue is the bolt strength. The other issue is lower deck deflection in the head, typically this is the lesser of the two issues.
Now that we started to play with Mustangs they have a similar problem when you push a certain HP level, specially seeing our blocks don't have the extra head bolts like a Stage II motor. That is why we always increase the size of the head bolts and look for an aftermarket head that has the thickest lower deck. These two tricks with Cometic gaskets is a great solution, in fact since we made this change we never had another head gasket issue with a Buick or Mustang.
There's no question the thin deck on the stock 8445 head is a major problem. I saw a major improvement in gasket retention back in the day when I was running Stg1 iron heads ( considerably thicker decks than the 8845) on my Stg11 block.
I would be using GN1 AL heads on this build NOT 8445's Personally I think the 1/2" studs would be a good improvement in holding these heads on the decks.
Saywhen ...Thanks For your input.
Am not sure just what method to go with. The recess in the bolt hole of the 109 block makes it a bit more complicated IMO.
If the existing 7/16" threads were to be taped out to 1/2" i believe the recess would have to be enlarged and keep. Now a Time Sert might be another option but I haven't checked that out yet. I know BlownV6 went from 7/16" to 1/2" studs on his Stg block without am major issues but 109 block deck don't look so simple.
That is an open ended question, seeing there are too many different scenarios out there.
The variables are endless depending on which gaskets your using, what head (GM 8445 heads are far weaker than Champion or TA), how well your filling the cylinders on the motor, and also including how the motor was assemled.
With that I have to ask the question regarding Melissa's car, I remember back when she ran this time with her car. I was amazed!
Because of this topic and knowing the performance level of this car, I have to ask what gaskets are on this motor, which heads, and how often do you run these numbers with this combination?
BTW, hope eveyone has a Nice Thanksgiving!
The variables are endless depending on which gaskets your using, what head (GM 8445 heads are far weaker than Champion or TA), how well your filling the cylinders on the motor, and also including how the motor was assemled.
With that I have to ask the question regarding Melissa's car, I remember back when she ran this time with her car. I was amazed!
Because of this topic and knowing the performance level of this car, I have to ask what gaskets are on this motor, which heads, and how often do you run these numbers with this combination?
BTW, hope eveyone has a Nice Thanksgiving!
She has Champion irons out of the box with cometic head gaskets. She ran a lot of 10.0s/10.1s. She ran the 9.94 an got kicked out at Cecil County in Md. Never had a problem with headgaskets or the steel heads. BUT we did put another motor in for the Reynold's meet with worn alum heads.. No problem with headgaskets BUT we ripped out a section of the head where the center rocker stand "was" on the second run. This is why I was questioning the need for 1/2" studs. Since then she has been busy with work and married life (I thought I taught her right that life was CARS
) . She still drives the hell out of the car during the summer. Took the Mazda motor (9.94 motor out of my Buick/RX7) out an put her new motor in. She's put maybe 8k on it so far. Goes pretty good :biggrin: Hopefully some suspension an rear end upgrades over the winter :biggrin:
