Timinva

Anyone know what ISB engines have pressed in hardened valve seats? I have heard that the eth engines do but the etc has induction hardened seats that are a part of the head casting. Then ,next I hear just the rv660 engines have the good seats. If anyone has noticed 24v heads are becoming hard to find. Last year I could get a new head easily now eveyone says they are not available. If the eth does have the good seats could someone pm me your engine serial number to help my search. Thanks Tim

Don M

The later HO engines have the press in seats. So do RV275 and 300 engines.

Pros: good durability, less tendency to crack into the casting

Cons: cost extra, has worse port flow in the low lift ranges, the valves will still pit even if the seats live a good long life.

I say if you have the EGT under control....skip them.

Spending the cash to shape the ports up can be an extra expense as well.

Don~

Timinva

Don, I was worried about the seats cracking and making a hard to find head worthless within 20k miles. I thought you were gonna shape the ports, that does not involve additional cost does it Tim

Don M

I like the idea of the seats, but the poor valves can crap out too. I guess the standard valve is somewhat inexpensive to replace, but the work to get to them can be time consuming and spendy.

I did a head here recently and used the inconel valves. I know they will hold up longer, but they are high dollar and when you need 12 of them on the exhaust side you run into some cash. I had to do everything including giving up my right arm to get them from Cummins back this summer. I was the first one to have them by about 3 months. The valves alone were like 400 bananas. There was not even pricing for them back then. I had to have an engineer buddy pull some strings at Cummins

The seats I used were the cobalt bad boys that just became available from Cummins last month...I had to give my left arm for those early too. Another 400 bananas and another favor owed.

This head will be on a truck that runs no more than 1500 degrees in EGT. IMO, the spendy stuff was not needed when you consider that most of the wear in these heads is the guides themselves. Skinny little 7mm stems.

Don~

jweir

Jeesh Don, how do you work with both arms missing??

Jim

joefarmer

I was wondering if anyone else caught that too! I do know that somehow Don answers the phone everytime and talks me out of my next stupid move. (I think you can buy arms on ebay Don! )

brandon.