sd33 sd33t cylinder head

[paulb]

Hi there.
I was told that the sd33 and sd33 turbo cylinder heads are different.
Is this really the case, how is it different. I bought a turbo engine but the head is cracked. I have a non turbo engine that would possibly have a good head. Thanks for any info!

[David Dixon]

Carey Weber posted a reply for you in the next thread.

I guess no one knows the answer but I can tell you who would. You can call Jesco or D and G Products. They can tell you if it is the same part number or not.

I bought a turbo head a while ago and my recollection is that the bare head is the same part. Bear in mind that my recollection quality sucks. If I had a good NA head I would be inclined to use it but would prolly check first. The most significant difference would be if they came up with some improvement in the casting process since 1980 that would give you a more durable piece if you bought a new one. And that's a pretty speculative and slight advantage.

-David

P.S. Numbers for D+G and also for Jesco are in the FAQ sticky.

[paulb]

Thanks I will give them a call and post what ever I find out.

[CareyWeber]

Sorry Paul I had a fowl ball.


I'm sure it has been done, but there are differences see pic.

[David Dixon]

Originally Posted by From the picture above

Cylinder head ports have been enlarged.

I missed that part.

[Türgi Mahvia]

Originally Posted by CareyWeber

I'm sure it has been done, but there are differences see pic.

It maybe all true
But not 100% true what SD33 and SD33T are with these differences.
Later SD33 and SD33T's are sharing everything - inc. piston cooling, 3 ring pistons, camshaft etc.

[CareyWeber]

Originally Posted by Türgi Mahvia

It maybe all true
But not 100% true what SD33 and SD33T are with these differences.
Later SD33 and SD33T's are sharing everything - inc. piston cooling, 3 ring pistons, camshaft etc.

I believe you are correct, but I have not opened up my newer SD33 to see if its a all updated. If we just talking about the Scout version of the SD33 vs the Scout SD33T then the updates are in the T version only.

[paulb]

Thanks guys. I called Jesco and was told that the older non turbo cylinder heads have different cooling. In other word more wholes for better cooling. He also warned me not to use a none turbo head gasket on a turbo engine or it will cover the wholes. But before I talked to him (I can’t remember his name) I pulled of the head from my 77 traveler. I don’t see any difference in the wholes. Maybe I need new glasses? I was also told that a new would run me $1,500 and to rebuild the old could cost $800. I think a rebuild will be my pick. I don’t want to experiment with the non turbo head.
Thanks again for the info!

[paulb]

Here is a picture of the heads The one on the left is the non turbo ( shinier )

[Eddie]

1. I'd get a late model head gasket and put it on the early NA head just to make absolutely sure none of the holes are covered up; turbocharged engines run quite a bit higher combustion temps than NA's. I'm reel suspicious of any counter monkey's assessment of your part.

Considering that the SD-33T was a pretty comprehensive redesign, Nissan Diesel may well have made some internal casting changes in the coolant cavities around the exhaust valves, which, as Turgi says, they implemented across the line. I suspect that is what JESCO's counter monkey was talking about.

2. I have what is purported to be a new SD-33T head casting which I bought from DG Products in 2006. It was delivered to me with a broken drill bit protruding from an intake port near the valve stem guide.

It turns out that John with DG sourced the head from another vendor and had it drop-shipped to me, and the upshot is that I still have this particular head despite voluminous e-mails with digital pics, etc. Caveat emptor definitely applies with either DG or JESCO.

Eddie