Ouch, is the head salvagable? I had my PDR stage 2 head crack the same way. Made for a expensive paper weight. Mine was between the two exhaust valves, I guess that the high egt's finally did me in. To bad it occurred so quickly, I was wishing to at least get 100000km out such an expensive part.

Lucky 12v heads are cheap(er) (comparably to any newer CTD engine stuff) Been told that there are two different quality levels for the heads, but thats just hear say.

 

How high were your egt's? how bad were the cracks?

 

I was around 1400 to 1500 deg's sometimes. I also ran for a year with no pyro

As for how bad, bad enough my engine couldn't build any boost and the truck smoked pretty bad. I wasn't leaking coolant, yet. Mine ran thru both seats, thru the head (inbetween the valves/seats). Its a common issue. some agrue where its from egt's or just bad castings. Whatever it is, I had to buy a new head. I'm at 260000km and on my third head. My latest head, I haven't been over 1300 deg's yet. I think that towing is the worst heat issue and the primary source for my failures.

 

John, get some lapping compound (280-320 grit) and lap your valves some, see if the cracks come out. Do a contact check to see if you have 100% contact on them. If the cracks are small, I'd run it personally. They aren't pressed in like later 24v's, so no risk of a seat dropping. You might burn a valve as worst case scenario, at which point you'd likely get a new head anyway. JMO.

 

The cracks are very small. Just a hairline that do not seem to go more than a 1/4 inch. Will see if I can get a good close up of the crack tommorow. Fluid damper, pistons, and 913 pump showed up today..... I think I just about have every little bit and piece that I will need to put this bad boy together. Except for delivery valve o rings........ Cleaned thew block and crank extra sparkly clean tonight and converted all my goodies to the 913 pump from my 911 pump tonight as well and drilled and installed roll pins for the fluid damper kit. Will finally start putting it back together after all this work, hopefully tomorrow.

 

Sweet buddy, I can't wait to see how it works for ya. Thanks to you, I might have to get into the engine building mood. The seed has been planted.

 

Just a few more pics........ I am really testing my patience trying to get the o-rings just perfect with a 45 degree overlap. I have one done completely and am getting the others dialed in a little quicker.

 

And another...... Cyl #1 has a .041 thou o-ring installed.

 

Looks good John. How wide are the actual grooves you are cutting? Seeing how yours turn out, I might have to do that on my spare engine. I have a spare block at home I can practice on. After doing the Q/A on both Kev's and my head, I am extremely disappointed in the job Trac has done. Especially after looking at the job that was done on Steve's head from PDP and Source Auto, those look great!

On a side note, any chance you could check piston protrusion before you get the rest of the rings in? We checked Kev's tonight, and I'd like to see how they compare against something fresh. Numbers mean nothing when you have nothing to compare to.

 

I am pretty sure the groove is .039, but will find out for sure and I will also get back to you on the piston protrusion.

 

Looks good buddy. Did you buy new pistons, and if you did which pistons did you buy?? They look awfully clean for the old ones? I want to build my engine this fall. How did you prep the cylinders? I was reading info on the ross website on prepping the cylinder so you get good ring seatin.

http://www.rosspistons.com/informati...stallation.pdf

http://www.rosspistons.com/informati...stallation.pdf

The old standby marine 370 is good choice. I might spring for the ross diesel pistons and have the pistons fly cut. They put on a extreme portection coating and are a full forged piston. The cummins engine is a cast/forging (what ever that means).

Swamp, I can't wait to see how your turns out.

 

jeez there has to be someone in your neck of the wood that could do a magnaflux on it , I know its a bit late now but sure be a shame after all the work you have done , lol go find one of the x ray tech that's zappin a pipeline, that way you wont get it dirty

 

Like Tate said, I wouldn't worry about the cracks, the worst case is you buy another head and port another head (your buddy did a nice job). Its just more beer. The 12v are decently priced vs. the 24v stuff. I want to see how the block orings work out and how much abuse that they can take. I know that those turbo can move air and make mega boost. I pushed over 80psi with them. My 12v engine will over 100psi, so I need to know. I don't want to use fire rings.

Swamp, I forget which studs your using. I can't wait to see what she does buddy.

 

Tate,

My piston protrusion is .016. But these pistons (Mike are you listening! LOL) are what Harry from Peak described as a Mexican Hat piston or AKA as just an industrial bowl piston made by Mahle. They are supposed to lower my CR ratio to around 15.3 - 1 depending on how thick my head gasket is how much machining I get done to the head and block etc..... And Tate to figure in the protrusion, I had .006 taken off the block for resurfacing so that number would definately be important in the piston protrusion calculations! Mike I am just using the ARP 625's 12mm. And preping the cylinders, I just had them honed out at the same shop that did the resurfacing of the block. Cyl walls were at the max alowable tollerence, but who wants a super tight engine anyways........ LOL

 

Swamp, you might balance out on the comp ratio. Cutting 0.006 off the block will raise compression ratio, and the orings will lower it slightly, so you kinda balance out somewhat there. Those pistons look good buddy, I might have to call Harry up for some good info on them as well.

What torque number you going with on the ARP's?

And on the tight engine, just rev her up to 5k buddy, you have the clearance.