Blown Head Gasket for the 2nd time... need some good sound advise this time.

turbodon

turbodon

New member
Joined
Jan 11, 2011
Messages
39
So at 185k my truck was bone stock. i pulled the plate and timed it to 21*
boom 1st drive down the street come back and coolant pissing from passenger #4 area. At this time i installed the standard ARP studs and a .020 over gasket.

it held up for about 15k miles.

today it started pissing coolant on the passenger side around #2 directly above the block heater plug in. Im bummin:bang

But now the truck has compounds he351 over garrett gta42 (71mm)
runs 60psi and has 24* timing.

both times it has only been coolant out the side... oil still looks clean!

So whats the deal, whats it gonna take to have this thing be reliable.
should i go back to a stock thickness HG?

Also on the timing.. when you do 24* measuring plunger lift with dial indicator... is it still 24* with 290bar??
i recently had 260bar injectors in and it felt like timing was affected a FEW degrees ATLEAST by the pop pressure.

Need to get back on the road ASAP this is my daily driver.

Thanks!!!
 
no o-rings or fire rings.
Also didnt check the block last time. head was cleaned and checked out strait tho.
 
Anything that raises cylinder pressures is going to make life harder on a head gasket. more timing, more air, methanol or nitrous.
Id at the very least run those ARP studs and orings on a flat head and block.
At 60psi and up if youre looking for reliability, you may want to spend the extra coin on the 625 studs. A lot of people have no issue with 425's at that boost level, though. Its all a crapshoot.
 
O-rings and go back to a standard thickness gasket if it wont cause any clearance issues. I would do 2-3 retorques after some heat cycles before beating on it at all.
 
Get the head resurfaced, check the block with a known flawless straight edge, clean the threads for the studs and make sure they have the proper (and proper amount of) lubricant on the threads prior to installation.

When you get it back together, I've got a timing light if you want to use it.. That is, if you're local!
 
i was running 18* set by dial indicator/ plunger lift method. but with the 290 bar injectors, it actually felt more like stock timing. i wanted my timing to be about 20* so I went to 24*(plunger lift setting) knowing the higher pop was seeming like it was retarding the timing. anyway despite the HG failure the truck was running better than ever before at this timing setting.

Sounds like i need to find a good machine shop in the Orange County, CA area who is competent of decking and o-ringing the head.

And btw no re-torques on the last HG job. checked them yesterday after it blew but none of them hardly moved at 135ft. lb. (where they were originally set)
 
I heard from a reputable source that raising the pop off pressure doesnt affect timing so much. It does shorten the injection event. I guess that could also make it run like it has lower timing.
I ran 300BAR for awhile.. it helped economy a bit but the power wasnt so good on the top end.
 
So got the head off just a little while ago.
block looks nice, head looks nice, gasket was pretty tore up looking between 2&3 which is right where it was leaking. so i think that explains that.

I called around today and have found a number of places locally that can pressure test, crack test, check the flatness of the deck, and deck it if need be.
Unfortunately, havent found anyone that will o-ring or fire ring it locally.
Still working on that.
 
I'm losing an amount of coolant myself. I think I'm burning mine but more or less the same issue. Will be investing in a new HG and some head studs as well. Gonna have it o-ringed, head checked and fixed as necessary for flatness and probably machine the rocker stands as well. I'm running stock valve springs as well, might as well change those while I have it out with easy access.
 
Quick question for those with more experience than I, is it possible to change the tappet cover with the head removed? I know the ideal procedure for it is with the pump off, but is it possible to reach down along side of it with the head off since the intake tract is no longer in the way? Maybe (I'm hoping) there's enough room. I'll change that while I'm doing the head I suppose. It's leaking a bit, typical.
 
turbodon said:
i was running 18* set by dial indicator/ plunger lift method. but with the 290 bar injectors, it actually felt more like stock timing. i wanted my timing to be about 20* so I went to 24*(plunger lift setting) knowing the higher pop was seeming like it was retarding the timing. anyway despite the HG failure the truck was running better than ever before at this timing setting.
Click to expand...

I'm running 300bar injectors, and have varied my timing from 18* to 24*. Never got the feeling that the timing was retarded that much as I went 260bar-280bar-300bar.
 
right on.
what timing setting do you like best so far?

Also called around more today... doesnt seem like there is anyone in the area to 0-ring the head.

so i think im gonna have it checked out, surfaced if need be, then just put a stock gasket in, torque the studs a little higher, and do a couple re-tourques and hope for the best. also turn the gate down a little on the secondary to get the over-all boost down to 50-55psi

sending it out of state is out of the budget and out of the time frame at the moment
:(
 
How's the spool-up on those twins? Quick spooling makes high early cylinder pressure which makes lots of fun-driving torque but is harder on the motor in general.
 
they spool VERY fast with a boost elbow on the he351.
With the new HG im gonna go back to the factory wastegate setting on the 351 which gates that turbo down to like 27psi rather than 40-42psi.
and in turn gets my over-all down to the 55-60psi range
is spools less violently like that but in turn, cuts down on some power and the fun driving torque in the seat of the pants
 
You must log in or register to reply here.
Back
Top