Competition Head sealing tricks for daily drivers?

[GO 4LO]

So what's the general opinion on o-rings vs. fire-rings vs. doubled-up setups? I keep hearing the fire-rings hold more boost, but also hear of lots of setups failing - is this due to poor machinework, or design problems?

What's everyone's opinion on max safe boost (with current technology for head-sealing) for a semi-daily driver? I've heard Maddog runs 100 psi and somehow got a copper gasket to work and seal well long term. Anyone run this much boost or more and care to share how theirs is set up?

Chris

 

[Bandit1]

i jsut had my motor fire-ringed by ADT and mine is a complete daily driver that gets hot dogged on the street, and it is holding up better than ever for almost 10k now. i talked to a lot of people about fire or o rings as far as reliability and i was told fire rigns although new are the best way to go. i have only heard of 1 or 2 that failed and that was due to poor installation or miscut grooves. installation is crictical and needs to be precise , since you are only dealing with a few thousands or an inch groove and also enough crush on the ring needs to be achieved again can be related back to installation an cutting of the grooves. i have heard that piers has good luck with the copper gaskets but not so much for daily drivers he can just get them to hold some how. hope this helps.

 

[chrleb1]

Fire ring is pretty much the best way to go. Basically the easiest and with the best results. When it comes time for me to do that, that is the way i am going to go for sure.

 

[GO 4LO]

Thanks, guys. What if you want to run more than the 120-130 psi that the fire-ring/14mm stud setup is supposed to hold? Any ideas then? I'm sure Mitchell and Scheid are running more than that, but they don't have to worry about their setups lasting 100k miles...

Chris

 

[ToolManTimTaylor]

Originally posted by GO 4LO

Thanks, guys. What if you want to run more than the 120-130 psi that the fire-ring/14mm stud setup is supposed to hold? Any ideas then? I'm sure Mitchell and Scheid are running more than that, but they don't have to worry about their setups lasting 100k miles...

Chris

@ 120-130 PSI The worry about a head gasket if far gone as the stock bottom end was gone 40K before the 100K. However could you imagine 100K on 100+ Pounds COOL!

 

[MCummings]

My truck, I bought used, went about 100K at 70PSI, and 20+* timing. The rod bearings were SHOT. VERY, VERY worn. All other bearings were good,, Main, and cam bearing. Looked great,, along with the cam,, but the rod bearings sold the pawn,, kicked the bucket, sang it's fairwell, wrote it's last will and testament, went 6' under..... You know how it goes.

Pretty much turned themselves into great conversation pieces.



Merrick

 

[ToolManTimTaylor]

Originally posted by ToolManTimTaylor

@ 120-130 PSI The worry about a head gasket is far gone as the stock bottom end was gone 40K before the 100K.

<hr>

Originally posted by Merrick

the rod bearings sold the pawn,, kicked the bucket, sang it's fairwell, wrote it's last will and testament, went 6' under.....

LOL I guess I coulda worded it that way

:-laf :-laf :-laf

 

[BillGotthelf]

Orings with 12mm studs are reliable to 70lbs. If you cut both block and head you can run 80lbs reliably. With 14mm studs you can see 110 lbs with just head ringed and 130 with block and head ringed. The depth of cut is extremely important, only a few thousands off and the head gasket won't last a week. I found out the hard way. I had my head decked make deepest cut . 040 and then recut all head rings to . 042-. 043. I then used the . 118/. 120 copper oversize rings. While I was doing this I had the machine shop check the valve seats and they had many small surface cracks. 98. 5-2000 heads had valve seats cut into the head material and 2001 and up had special hardened seats pressed into the head to stop the cracking. Any good machine shop can recut the valve seats and press in the hardened seats. Then you need to check the loaded valve spring heights and have the machine shop cut the seats so that the valves all have the same loaded height. This will allow you to run shims which will help with boost pressure higher than the spring pressure which holds the valve open slightly. At TDC the piston smacks the valve closed-boost 70lbs or more. Watch for coil bind on the valve springs-you should have at least . 060 between the coils on the valve springs. Damn I gotta stop telling all my secrets.

 

[GO 4LO]

Thanks, Bill - great info!

Chris

 

[CumminFast]

We oring to . 010 and 12mm studs to 150ft lbs. It holds 80 lbs.

 

[Sled Puller]

Merrick, bring a rod bearing to Muncie, I want to see what timing does to them.

 

[MCummings]

I'll get ahold of Chris... I'll see if he still has the old bearings. .



Timing + RPM = dead rod bearings.



Merrick