Can’t keep my head down.

Be careful using the Isky tool.
It works but one guy I know messed up his block somehow with the Isky tool.
PDD and others have used 425's torqued to 140 lbs with o-rings, it takes 2-3 heat cycles and retorques to get the head pulled completely down.
 
Destroked 450 said:
Be careful using the Isky tool.
It works but one guy I know messed up his block somehow with the Isky tool.
PDD and others have used 425's torqued to 140 lbs with o-rings, it takes 2-3 heat cycles and retorques to get the head pulled completely down.
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They are who I talked to and they recommend I use that tool. Does seem pretty scary cutting into my block. Hopefully all goes well
 
't understand why you 425's, and say about 80 psi everyday I drove it. How much fuel are you putting in there? Granted I was on a cr, but still, are you following the torque sequence? did you bottom tap? is the blow in the same cylinder each time? move injectors and see if it follows an injector? tossing ideas at a crazy problem, last, did the machine shop do a good job cutting the head.
 
Fast12v said:
They are who I talked to and they recommend I use that tool. Does seem pretty scary cutting into my block. Hopefully all goes well
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Isky Grove-O-Matic tool as been out for years and used successfully by many.
Not sure how he set the tool up but somehow got the tool body down hard on the block, as he turned the tool to cut the grove the tools body scored up the top of the block.
Not saying don't use it, just be careful setting it up.
 
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Fast12v said:
Can’t find any shops around me to cut orings. Thinking about buying that isky oring t cutting tool and just cut the grooves in my block myself. Has anyone ever used this or any reasons why I shouldn’t do this?
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Where are you located?
I believe Brad at Poncis Diesel Center does orings
 
That’s about 6 hours away from me. I’ve found a few places near me that said they could do it now. But I really don’t trust them too much after talking on the phone with them. I think cutting it myself is the best way to make sure it’s done right.
 
mikmaze said:
't understand why you 425's, and say about 80 psi everyday I drove it. How much fuel are you putting in there? Granted I was on a cr, but still, are you following the torque sequence? did you bottom tap? is the blow in the same cylinder each time? move injectors and see if it follows an injector? tossing ideas at a crazy problem, last, did the machine shop do a good job cutting the head.
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Yes everything is done right when doing the head gasket. After talking to a few shops I’ve came to conclusion that with a compound turbo setup there is too much drive pressure created to keep the head down with arp 425s alone. I think cutting the orings and buying some 625s will be the best solution. If only I can save up enough to buy those 625s.
 
Long before 625s came along, many of us got by without blowing gaskets regularly.

Double check your head and your block for flatness. If you can save the money for the 625s that’s great. But if you have to pick between o-rings and 625s, I’d take o-rings and 425s over 625s ans no rings. Obviously depending on the budget and timeframe.

Work on checking drive pressure and verify your timing.


All that being said, 70psi on a studded, non mls gasket, non o-ringed Head, sounds like a lit fuse to me. I wouldn’t plan on it living a long life. Maybe if it were a high winding setup. But with the pressures your setup can generate at low lower RPMs, I would almost expect head gasket issues.

I’m not knocking on you. I’m just calling it as I see it.

If Ponci is at all possible for you to get your head to, get it to him. He’s a good guy. Part of the old school performance diesel world and he will steer you in the right direction without bending you over a barrel.
 
PDD had a post about this very issue not long ago, they got it sealed using o-rings and 425's torqued to 140 lbs, at took 3 heat cycles and retorques before the head settled completely down.
 
How is it that mine is still holding at 60 psi of boost on stock bolts ? Never been retorqued as far as I know. I’m at 20* right now and plan on buying some 425s soon
 
I'm skipping all of this. What RA were the mating surfaces milled to? If they are too smooth, the gasket will migrate.
I'm not certain, but IIRC, it nerds an RA of around 60 to have enough Asperity to retain a gasket in this application.

Sent from my XT1575 using Tapatalk
 
SCHMITTY said:
How is it that mine is still holding at 60 psi of boost on stock bolts ? Never been retorqued as far as I know. I’m at 20* right now and plan on buying some 425s soon
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There’s quite a difference in cylinder pressure between your setup and his. Plus with the k31 your power comes on higher in the rpm range.

Big singles are easier on headgaskets and on rods than compounds.
 
Biggy is on the right track as well, surface texture makes a difference. I thought about that one as well. But at this point I feel he is a candidate for o-rings and if he takes it to a good shop, the surface issue should be addressed at the same time.
 
Crawler said:
Long before 625s came along, many of us got by without blowing gaskets regularly.

Double check your head and your block for flatness. If you can save the money for the 625s that’s great. But if you have to pick between o-rings and 625s, I’d take o-rings and 425s over 625s ans no rings. Obviously depending on the budget and timeframe.

Work on checking drive pressure and verify your timing.


All that being said, 70psi on a studded, non mls gasket, non o-ringed Head, sounds like a lit fuse to me. I wouldn’t plan on it living a long life. Maybe if it were a high winding setup. But with the pressures your setup can generate at low lower RPMs, I would almost expect head gasket issues.

I’m not knocking on you. I’m just calling it as I see it.

If Ponci is at all possible for you to get your head to, get it to him. He’s a good guy. Part of the old school performance diesel world and he will steer you in the right direction without bending you over a barrel.
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Yes I completely agree 70 was too much. When that head gasket blew it was on the first day that I was testing out the entire build I just did. Once I saw the 70psi I thought “wow that’s a little too much I need to lower that”. When I got back to my house it was already too late. As far as the 625s I have the money to buy them it’s just I really don’t want to have to buy them. If you think 425 and orings will be good I will run with that. As far as drive pressure goes. I will setup a gauge and see how close it is to that 1:1 ratio that I want it at. If it’s too high what are some ways you can lower drive pressure?
 
70psi total boost number Is nothing, it's a set of quick spooling smaller compounds that come on quick and make alot of torque down low that gets them. Especially if you like to pull it hard down low. O-ring with your 425's and do a retorque and all will be good as long as the o-rings are located properly and the correct protrusion.
 
jasonc said:
70psi total boost number Is nothing, it's a set of quick spooling smaller compounds that come on quick and make alot of torque down low that gets them. Especially if you like to pull it hard down low. O-ring with your 425's and do a retorque and all will be good as long as the o-rings are located properly and the correct protrusion.
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Correct me if I’m wrong but for my setup if I run 70psi of boost vs 55psi that will cause my drive pressure to go up. How can I run more boost while keeping my drive pressure down? Or is it just the fact that I have too much pressure at lower rpm. I know when I do the orings that will help hold more pressure but I’d still rather lower my drive pressure if I can to make it easier on my head gasket.
 
Drive pressure isn't what pushes a gasket, it's cylinder pressure. That's why guys with a lazy single can get away with more on a stock head. With quick spooling compounds it makes alot more torque down low on a gear shift or lockup. But that's why we love compounds, decompressing is also another option. I had good luck with a .020 gasket back when I daily drove a stock 12v.
 
Back when we (PDD) were testing the new SX-E turbos, we had a 1995 12v test mule of a truck known as Oscar. It was a 280k original head gasket and overtorqued/retorqued factory head bolt setup. We tested numerous single turbo setups ranging from 58mm up to and including a 369sxe. Never had a head gasket issue .... until we installed the PDD towing compounds 58mm K27 over a 369sxe. The very first pull on the dyno lifted the head and blew the head gasket in several places. It was amazing after months of abuse, employees beating on the truck, burnouts, cold engine abuse, etc. and never had a single head gasket issue until the compound turbos. The compound setup made essentially the same horsepower on Oscar as the single 369sxe, but the compounds made almost 200 more ft lbs of torque and made the power at lower RPM producing just over 1000 ft lbs at 2000 rpm whereas the single 369sxe was under 800 ft lbs at 2000 RPM.

For years the internet myth of high drive pressure blowing head gaskets has been regurgitated over and over. High exhaust drive pressure is not a factor in head gasket damage. However, high drive pressure is a decent indicator, marker, sign, etc. of the potential for head gasket failure because a fast spooling monster torque turbo setup generally chokes out earlier in the upper rpm range and will therefore have higher drive pressure. So the fact that a turbo system comes on fast and early usually means it will have higher than average drive pressure
 
There's a guy in Tx on the other forum that would probably make you a good deal on his.
If interested I'll PM him and ask if you can contact him.
 
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