I'm getting ready to help my buddy do a head gasket on his 90 CTD. Here are my questions

-Should the head be taken to a machine shop and surfaced along with a pressure check? And what would the cost be expected on something like that?

-Any other machine work that should be conisdered?

-The head gasket itself from what I have read should be from cummins. Whats the cost run on those and are there different thicknesses that I need to be concerned about?

-Also if anyone knows a good cummins dealer in the chicago area that would be helpful?

-Anything else that would be recommended while the head is off?

From what I have been told this is not a bad job. This will be a stock truck no mods and the buddy is fairly budget minded for lack of a better word. He realizes you get what you pay for but no one wants to get hosed.

 

Yes, The head should be taken to a machine shop to be decked before reinstallation, and the block should be prepped fairly well. I would buy new bolts with the gasket also. I am under the impression that cummins has quit making a regular gasket and only the marine gasket is available. Depending on how much material needs taken off the head, I would consider the .10 over marine gasket. Stay away from the .20 over because it will cause hard starts in cold weather

 

Ahem . . . . there is no such thing as a "Marine" gasket.

The gasket Cummins uses in the 5.9 is the same be it automobile, boat, or industrial. There are no special gaskets as provided by Cummins.


Head bolts? Just drop them individually to a concrete floor. If they "Ring". use them.

 

Sorry to pop your bubble guys, but the +.010 and +.020 thicker gaskets where meant to be used when the block deck had to be resurfaced. They just happen to work well to drop the compression just a tad.

Check for cracks, have it decked. I would definitely consider new bolts, a 1990 engine will have the old design bolt. Another member here had a blown head gasket because there wasn't enough thread on a bolt. Your buddy currently have the straight torque bolt, the newer bolt is torque plus tighten in another 90*.

 

Whats the deal with these new Cylinder heads on ebay? Looks like for about 500.00 I can have one sitting here. Are they any good? I hate to sink machine work into an old head.

 

I had a brain fart earlier.

You'd do well to have your bud invest in a FSM. Then read-up on the 5.9 head work as there's a limit as to how much one can take off the head before the valves need to be sunk some. Even then, the OEM integral (induction hardened) seats can only be cut so much. After a bit there, you have to cut them out and install replacements.

 

Perhaps those who know best will chime-in but it's my understanding they may be manufactured by folks from "outa-town" and as such, may not be of the quality one might expect direct from Cummins.

 

i believe garrett at puredieselpower.com has heads that are made in a cummins casting plant. they arent that expensive, you can get the heads ported and oringed decked and valves oversized and what not, i also think you are going to need to get injectors for the new head. as far as i know bc is correct but your head shouldnt be out that much.

 

Have the head checked, especially since it's a non-intercooled engine. Ask me how I know. Expect to pay between 50 and 150 to have the head checked for holding pressure and adjuting for straightness. There is an 'acceptable' amount of cracking allowed by Cummins, so be sure the machine shop is diesel savvy. A gasket will run between 75 and 100 bucks. Money well spent is a Cummins gasket and quality machine work. My head bolts all checked out well within spec, and my engine has nearly 500,000 miles and was assembled in 1987. The bolt stretch gauge is simply a piece of cardboard and it's a go, no go sort of thing. Check your bolts and run 'em if they're within spec. Oddly, the longest bolts on my heap were dead on, while the shorter ones were somewhat stretched.

 

I have an FSM for my 93. I'm guessing they are just about the same specs for the engines?

 

Well i'm going to stop in at the cummins dealer in the morning after work. They have pretty sweet hours 7am-midnight and they are right on the way home. Am I going to need all the engine data thats on the tag of the truck that I won't be able to see? Or can they figure it out with out all that info? I figure I'll also ask about machine work.

 

From my experience's with cummins, you are going to need the numbers off the motor.

 

Well Here are the prices I got from Cummins.

Head gasket set- P/N 4089649 213.00
Bolts P/N 3920779 6 @ 3.35
3920780 14 @ 4.43
3920781 6 @ 7.22
If I need a .010 or .020 over gasket i would have to get those seperate.

.010 P/N 3283336 60.00
.020 3283338 77.00

How does all that sound? Fair or getting hosed? The head bolts I'm still thinking replacing them would be above and beyond for what the truck is. This is also considering they can be measured for length or the drop test to see if they are still servicable. If they were junk after one use cummins would flat out plaster that all over the place.
My buddy is working his connection thru the local parts guy to see what kinds of cummins stuff he can get his hands on. I know to go with the cummins head gasket but what about the rest of the gaskets? Would any good aftermarket gaskets do the job??
The Engine # was needed. And it was a 15 minute project to look this stuff up there at the dealer. Everything except the thicker plates were in stock.

 

I just had a hg done and Cummins updated gasket was used and new bolts. My head or block never had to be milled or changed. Hope it helps. Order from CUMMINS!!

 

Seems to me that head gasket needs to be looked at, I just did mine about 2 years ago, and the HG was nowhere near that expensive,
my engine had about 315K when I blew the gasket, I replaced the HG only and foolishly didnt have the head checked out, Well that was over 30K ago and it sees 40lbs boost alot,
I am just lucky.
Peter