Engine/Transmission (1998.5 - 2002) I have a few twin questions

[KKunz]

Just got done building my twins for my 99. Twins are a hx35/12 with a ht3b/26 they work great low egts and fast spool up. The most boosts I can hit is 48 psi which seems about right. My questions is will I need to get head studs or am I still safe with that amount of boost? Also with the stock hx35 modified to wastegate on all 6 cylinders will I need to get an external wastegate? The hottest I have seen my egts get is 1300.

 

[Cummins724]

The most boost that you should run with a stock gasket is 40psi. I would get it changed soon or turn it down until you do. I've heard of gaskets failing @ 40psi too.

 

[J.Keith]

Thats exactly the same setup that I'm using.

I've hit as high as 52 psi and had to back out of it because it wanted to go higher.

I setup the Edge Attitude to defuel @ 50 psi and I've been running that for about 3000 miles including some vey heavy towing, drag racing and a couple of hooks to a sled. So far no problem but I'm putting Mach 6's in this week and I fully expect to blow the headgasket.



The highest EGT's that I've seen so far is about 1200 and that was when I was grossing about 27k.

 

[KKunz]

Will head studs be enough or do I need to o-ring?

 

[KKunz]

what about the wastegate?

 

[AFarmer]

While you've got that thing off I'd get it o-ringed and not think twice. Most shops now are doing them for around $300. You won't regret spending that. You may be able to get away without it but it's that calming reassurance that makes that money easy to spend.

 

[KKunz]

so the head comes off when studs are instaled?

 

[Signal73]

if just 12mm studs, no. you can get the longer ones in through the plugs in the cowl.

 

[AFarmer]

You can do studs without taking the head off... . a little aggrevating. To do it right take the head off get it o-ringed. That's money well spent.

 

[KKunz]

Ok I will send off my head for o-rings. Where would you suggest to have it done what is the turn around on the job? As far as the external wastegate goes do I need to do any thing there?

 

[RHARVEY]

Been running stock gasket for 15k with my twins and stud'd head. Blow off valves are set at 50lbs. . So far there are no leaks no drips no errors... ! I dont use the high boost numbers when the motor is cold. . I am running the PDR towing twins with a 12cm housing instead of a 14. I wanted as much boost as I could get at my towing rpms. I set the wastegate on the 35 to between 24-26 to help with the head pressure. . It not hard to see the boost needle jump to 50lbs when I am getting on it hard...

If its not leaking... do the studs and leave it until it does. .



Rick