Best HG for O-ringed head?
01-10-2006, 07:09 PM
#31
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gcb951
"O" rings are a 1-time use product. Since you have the head off, you should have the "O" rings replaced.
If you're using a Cometic, then have the "O" rings picked out.
TonyG
"O" rings are a 1-time use product. Since you have the head off, you should have the "O" rings replaced.
If you're using a Cometic, then have the "O" rings picked out.
TonyG
01-10-2006, 07:40 PM
#32
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Tony, on the cometic with o-ring; did the o-ring match the dimples in the cometic? Talked with Neil about this once, just curious if you measured and they matched, as this was his recommendation if it was used together.
01-10-2006, 08:01 PM
#34
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Ski
I don't remember. The real problem with using an "O" ring with the Cometic is that the "O" ring tends to cut into the outter layer of the Cometic.
I just pick out the "O" rings, leaving the "O" ring receiver groove intact when using a Cometic with an "O" ringed head. Works great.
TonyG
I don't remember. The real problem with using an "O" ring with the Cometic is that the "O" ring tends to cut into the outter layer of the Cometic.
I just pick out the "O" rings, leaving the "O" ring receiver groove intact when using a Cometic with an "O" ringed head. Works great.
TonyG
01-10-2006, 08:11 PM
#35
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Originally Posted by TonyG
RolexNJ
Checking out your site...
"530 BHP & 467 TQ FlyWheel @18 PSI : Formula = 461.4 RWHP & 406 TQ x 15% Drive Train Loss"
Your math is incorrect. The formula should be:
461.4/.85 = 542HP at the crank assuming a 15% drive train loss.
Also, you should post a dyno chart that is SAE corrected, not Standard. SAE corrected charts are comparable. Standard charts are not.
TonyG
Checking out your site...
"530 BHP & 467 TQ FlyWheel @18 PSI : Formula = 461.4 RWHP & 406 TQ x 15% Drive Train Loss"
Your math is incorrect. The formula should be:
461.4/.85 = 542HP at the crank assuming a 15% drive train loss.
Also, you should post a dyno chart that is SAE corrected, not Standard. SAE corrected charts are comparable. Standard charts are not.
TonyG
01-10-2006, 08:43 PM
#36
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To all here...
My comments to RolexNJ were not intended to flame. Quite the opposite. He's making more power that what his web site indicated....which was intended to be an indirect compliment.
Again... no flame intended.
TonyG
My comments to RolexNJ were not intended to flame. Quite the opposite. He's making more power that what his web site indicated....which was intended to be an indirect compliment.
Again... no flame intended.
TonyG
01-10-2006, 09:02 PM
#37
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Another issue with O-Rings is "brunelling" (spelling?).
The wire used is typically stainless steel which is very hard. After the head is torqued and put into use, the clamping/shuffeling forces will eventually cause the s.s. wire to sink into the softer aluminum surface of the head. This is known as "brunelling". With time the s.s. "O-Ring" becomes useless.
As Tony G states, use the Cometic gasket.
The wire used is typically stainless steel which is very hard. After the head is torqued and put into use, the clamping/shuffeling forces will eventually cause the s.s. wire to sink into the softer aluminum surface of the head. This is known as "brunelling". With time the s.s. "O-Ring" becomes useless.
As Tony G states, use the Cometic gasket.
01-10-2006, 09:06 PM
#38
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Originally Posted by TonyG
To all here...
My comments to RolexNJ were not intended to flame. Quite the opposite. He's making more power that what his web site indicated....which was intended to be an indirect compliment.
Again... no flame intended.
TonyG
My comments to RolexNJ were not intended to flame. Quite the opposite. He's making more power that what his web site indicated....which was intended to be an indirect compliment.
Again... no flame intended.
TonyG
01-10-2006, 10:03 PM
#39
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I know this has been beaten to death, but has anybody come to a consensus on whether the head, block or block and head need to be surfaced? Has Cometic or Neil at PD ever chimed in on the appropriate preparation?
01-11-2006, 01:22 AM
#40
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Originally Posted by David Floyd
Cometic say's not to use there gasket with o-rings, at the time I had no choice and did use my o-ringed head with a Cometic and no problems so far.
...
...
There is a substantive difference in saying: A. “we do not recommend using O-ringed heads with our Cometic gaskets” and saying: B. “we recommend not using O-ringed heads with our Cometic gaskets
A. Means not necessary and B. means not advisable.
Having run O-ringed head with 23-25 psi boost has not shown any (gasket related) problems for me either. Yes, the O-ring left an indentation in the HG, but not to an extent that caused me concern. In other words I think interpretation A. is the right one.
This reminds me of (a representative of) Cometic saying we do not recommend re-use of our HG, but very few people who have done it have had a problem. So I re-used a 100 mile old HG (for scheduling reasons) with no problems after 2 months of use.
Laust
