high egts

tlse1

tlse1

Need more Input
Joined
Feb 4, 2007
Messages
67
Hi all I have a little problem going on. I have a customer with a 98 12valve with egt problems. Before I got the truck he had installed a tweaked up p pump and was told incorrectly about egts and melted down 3 pistons. This resulted in an full overhaul done by a professional diesel mechanic and machine shop. After a break in period of about 5k or so he decided to start turning it up with a step 10 tst torque plate with his stock p pump. With stock injectors and turbo and 15.5 deg of timing egts would reach 1600 plus with only 27 psi of boost. This is where I got involved I had found the turbo had been fried by the tweaked p pump and a cracked intercooler. The turbo was replaced with one of my own hx35/40 hybrids with a 14cm wg housing.The intercooler has been replaced with a Piers unit. After this 27 psi of boost and high egts. I then pressurized the system and found a blown head gasket. I removed the head performed a port and polish and had the head o-ringed and 12mm head studs installed and bumped the timing up 17.5 deg. Now the egts are better and boost will get to 32 psi but egts at around 2500 rpm will climb for 1600deg. Oh yea I forgot to mention he has a 3k gsk in the stock pump as well . He said that before he installed the tweaked p pump that he wasnt running into these kinds of problems and remember it making 37 to 40 psi of boost. I am pulling my hair out and starting to think crazy thoughts like possibly the cam being installed a tooth off . The truck starts good even cold and doesnt seem to have a large amount of blowby. The cylinders looked good when I had the head off no glazing or scoring. Any thing any one can come up with to help would be great. Thanks in advance
 
I really don't think you're running enough turbo in that setup. I would consider something much larger than a hybrid. JMHO of course.

brandon.
 
tlse1:

Welcome to the website!

Your suspicions on that cam could be causing that problem. I would suggest trying to raise the timing a little more, maybe to 18. I know that when my 96' Dodge CTD 12 valve was more stock than it is now, I also fought EGT problems but not as severe as your friends truck.

On that boost being down, I would re-check all the boots and clamps in the air and intercooler system! I have seen the boots with very small cuts near and around the clamps that can cause problems with leaks etc. I would also look into finding a 16cm housing for that turbo. I had a 14cm on my 96' and can tell you the 16cm housing worked much better for the EGT problem.

Hope this helps you some. Good luck.

--------
John_P
 
The plan from here is to install a compound system using the hybrid turbo as the high pressure turbo. I just wanted some more insight to see if I was over looking anything. This guy has spent a lot of money with me so far and I just want to make sure he is getting his moneys worth. I cant thank you enough for your advice.By the way as an after though I have pressurized the air intake system to 48 psi with shop air and couldnt find any leaks.:thankyou2:
 
i have a truck, just about like that one. the egts were just high no matter what. we even pulled off the pump and had it checked out. we finally put a set of twins on it and it stays under 1300 now. i never really though about the cam. i have worked on 20 different 12v trucks and this one was just hot from the get go. it is right at 500 rwhp now and a really nice tow rig, hx35 over a ht3b.
 
Thanks gunracer1 .I had the p pump on it now set up on a pump stand also with no changes in egts. I always seem to get these weird ones. At least the customer has been very understanding and willing to work with me. I will let him know about your truck and that the twins did work.
 
I forgot to get back to this one I went with a S400 for a low pressure turbo. The system will make a max of 50psig of boost with 30 of it coming from the s400.Right now I cant get the egts over 1350.Which is perfect for him because he tows a lot and can't watch his pyro like a hawk.The system spools amazingly quick and has little smoke for a ppump.So far he is averaging 19mpg unloaded and 15 mpg loaded .I need to get to spin it on the rollers to see where it is at power wise but if I had to guess I would say it is close to 400 rwhp just by the old assometer.
 
Where is your shop at? I live down by Longmont, maybe I'll have to come swing by sometime and say hey!
 
Sure that would be great I am in Berthoud.So not to far from you.Give me a shout 970-691-4861
 
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