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I'm currently running 347 big bore with 3.25 stroke with the unported Victor JR heads which I doubt flow anywhere near the AFR or highport heads.

I've been 5.50s & 8.50s at 3400 lb with current combo and 20 psi. I'd love to turn the boost up to 30 psi to get into the high 7s, but I don't think my head lifting issue is going to allow that.
which block ? get ahold of me, there are a few things that are not public info about head lifting with SBF blocks.
 

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Discussion Starter #24
Check my sign. That's with inline Brodix Track 1 heads on a 4.080 bore 347 with a single GTX5533R 98mm. Head lifting is always an issue. I change head gaskets every 10-15 passes.
What HGs do you use? Do you resurface the heads each time? What do you see when you pull the heads off each time? Signs of the gasket going south? Bleed trails?
 

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What HGs do you use? Do you resurface the heads each time? What do you see when you pull the heads off each time? Signs of the gasket going south? Bleed trails?
I use Clark cooper gaskets with o-rings on the block and receiving groove on heads. We see black smoke between heads and block after 8-10 passes. Nothing between cylinders. No resurface on heads, just gasket replacement.
 

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O-ring the block. I run 30psi with a 88 garret and still use 933pt1 gaskets. I did split my first set of gen 1 heads. The breach was external not into the cylinder. The gen 2 heads have a ton of meat around the plugs. Bottom 5 at 140 sbf 306.
 

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I use Clark cooper gaskets with o-rings on the block and receiving groove on heads. We see black smoke between heads and block after 8-10 passes. Nothing between cylinders. No resurface on heads, just gasket replacement.
Do you ever re-torque your heads after the initial start up and heat cycle with new gaskets ??

I've just gone with cooper gaskets and o-rings on my Brodix heads.. My engine builder said I should re-torque my heads after the first heat cycle.. This should be done with the engine cold after an over night cooling off.. Then they should be re-torqued again cold, after the first full power hammering..

They should be torqued one bolt at a time.. Turning them off a quarter turn, then pulling them back to 110 ft lbs..

Also... Have you had your torque wrench calibrated.. My high quality "Snap-On" clicker type torque wrench.. Actually needed to be set at 135 ft lbs just to reach a verified 110 ft lbs..
 

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Do you ever re-torque your heads after the initial start up and heat cycle with new gaskets ??

I've just gone with cooper gaskets and o-rings on my Brodix heads.. My engine builder said I should re-torque my heads after the first heat cycle.. This should be done with the engine cold after an over night cooling off.. Then they should be re-torqued again cold, after the first full power hammering..

They should be torqued one bolt at a time.. Turning them off a quarter turn, then pulling them back to 110 ft lbs..

Also... Have you had your torque wrench calibrated.. My high quality "Snap-On" clicker type torque wrench.. Actually needed to be set at 135 ft lbs just to reach a verified 110 ft lbs..
Yes on the re-torque after the first heat cycle but what I do is put two heat guns in the water inlets after the first torque then check the temperature of the heads with a laser gun and let them cool overnight to re-torque the next day. I for sure need to check the calibration on my torque wrench, I torque the heads to 115 ft lbs.
 

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Yes on the re-torque after the first heat cycle but what I do is put two heat guns in the water inlets after the first torque then check the temperature of the heads with a laser gun and let them cool overnight to re-torque the next day. I for sure need to check the calibration on my torque wrench, I torque the heads to 115 ft lbs.
You just make way too much power. Awesome.
 

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You just make way too much power. Awesome.
Thanks, Right now we are switching from C16 to M1 looking for more HP and less weight. I'm in the process of filling the heads solid with Devcon liquid aluminum to try to cure the blown head gasket issue. Wish me luck.
 

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Thanks, Right now we are switching from C16 to M1 looking for more HP and less weight. I'm in the process of filling the heads solid with Devcon liquid aluminum to try to cure the blown head gasket issue. Wish me luck.
The methanol will help your head lifting issues due to much lower egts keeping heads more rigid. I would consider going to the Top Fuel Hoops. They are a better setup all the way around. With a conventional o-ring reciever groove setup the gasket is only pushed into the head's receiver groove. 010-.012" and it's a semi circle seal. If the head lifts at all it is very easy to have leakage on the head side of the gasket first and possibly fire slotting the head. The Top Fuel Hoops are cylindrical with one side being square and the other a .050" radius. The square side goes into a square groove in the head ~.060" deep as a light press fit. The receiver is in the block and can be from .018-.022" deep so nearly double the engagement of an o-ring setup. Exhaust gas has to make four 90* turns to leak on the head side and the block side is sealed almost as bulletproof. I only recommend using Clark copper gaskets, they have no equal. Anyone that tells you they are all the same is full of shit. I really like hat(insert) washers in the heads as well. They keep from deforming the material around the top of the holes in the heads and pushing material into the holes causing loss of clamp load. This becomes much more important at the high torque loads on 1/2" studs or tool steel studs for that matter. Hope this helps.
 

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The methanol will help your head lifting issues due to much lower egts keeping heads more rigid. I would consider going to the Top Fuel Hoops. They are a better setup all the way around. With a conventional o-ring reciever groove setup the gasket is only pushed into the head's receiver groove. 010-.012" and it's a semi circle seal. If the head lifts at all it is very easy to have leakage on the head side of the gasket first and possibly fire slotting the head. The Top Fuel Hoops are cylindrical with one side being square and the other a .050" radius. The square side goes into a square groove in the head ~.060" deep as a light press fit. The receiver is in the block and can be from .018-.022" deep so nearly double the engagement of an o-ring setup. Exhaust gas has to make four 90* turns to leak on the head side and the block side is sealed almost as bulletproof. I only recommend using Clark copper gaskets, they have no equal. Anyone that tells you they are all the same is full of shit. I really like hat(insert) washers in the heads as well. They keep from deforming the material around the top of the holes in the heads and pushing material into the holes causing loss of clamp load. This becomes much more important at the high torque loads on 1/2" studs or tool steel studs for that matter. Hope this helps.
Brian, email sent.
 

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All you have to do is move some gas one time across the MLS gasket and it is compromised.

From wherever reason, a tuning hickup, ect. They are never going to be right until changed

When the hot combustion gas flows betweens the layers the embossments loose their spring

Replace, make sure everything is true and the tune is on point and you won't have issues
 

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Discussion Starter #40
O-ring the block. I run 30psi with a 88 garret and still use 933pt1 gaskets. I did split my first set of gen 1 heads. The breach was external not into the cylinder. The gen 2 heads have a ton of meat around the plugs. Bottom 5 at 140 sbf 306.
Good info. Thanks. Do your heads have much if any porting?
 
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