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6.2 // 6.5 precups

Missy Good Wench

Missy Good Wench

Wild Blonde from Cloud Mt
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Location
Newberg Oregon
Does anyone have a good listing with pictures of the different precups that have been used in the 6.2 and 6.5 engines.

GM has used a buttload of different ones over the years.

I would like to find some good info on this subject to include in my build tips thread.

So far I have searched the net well and turned up nothing.

Thanks

MGW
 
Here is a post that I copied off a sticky thread by maxpf on a certain K5 blazer forum in colorado:




I had to dig around, but I was able to find every (or at least most ) precup part #'s.

Discontinued part #'s

23500082 - 1 dot - 6.2L "C" code - 1982-1990

14525518 - 3 dot - 6.2L "J" code and military - 1982-1990

10149688 - 3 dot with a @ (circle A) - 6.2L "J" code and military - 1990-1992

10163707 - 1 dot with a © (circle C) - 6.2L HD/Commercial - 1992 only


Currently available part #'s

10149630 - "T" - 6.5L "F" code - 1993-1994

10230426 - Square - 6.5L "Y" code (and presumably military) NA - 1994-up

10149629 - Circle - 6.5L "S" code - 1994-up

10183926 - Diamond - 6.5" "F" code - 1997-up


You will notice that there are some holes in the listings. For instance, what cup was used in 1991-1992 "C" code motors? Also, there is no mention of what cup was used in the 1995-1996 "F" code 6.5's, although I believe it was the "T" cup. If anyone can fill in the holes, please do.

Also, the old "fuel economy" 6.2 cups are no longer available. I don't know this for sure, but I would bet the "Y" code 6.5 NA cup would give the best economy out of all the currently available parts (it has the smallest throat out of all the 6.5 cups). The "Diamond" cups are generally regarded as the best for maximum power in turbo apps.
 
Great stuff guys.

The pic is nice but the clarity is a bit iffy.

From what I have dug up is the diamond heads can be used on all applications.

The descriptions seems to be very scarce.

Thanks for the info

MGW
 
I have the diamond precups and I have no complaints :). They looked good, with no cracks, just a little 'chip' on the edge. The head rebuilder recognized them instantly as 'diamond precups' and noted they were in great condition and that little chip is common and completely normal. He must have known a thing or 2 about 6.5's. Viewed after 120,000 miles. One head. Driver side.
 
Hey uuuh, wouldn't mind sharing a photo of one of those Diamond Cups wouldja? I'm getting a shopping list of pieces parts for an upcoming build also.
 
The diamond ones are the late stuff but the "T" cups are almost the same and will work sweet.

The issue is, they crack at the upper corners and if these cracks get longer than about 3/16 from the port it would be better to use them for a paper weight.

Tooooooo much work to have a failure then need to rip it apart again.

MGW
 
You are welcome

On this build I am keeping the DSLR camera handy at all times during the build.
My intent is to capture every little nuance as it goes along.

The 6.2/6.5 is very little different than a 454 or even a mouse motor. Its a V8 engine and other than the injection system and such there is little difference.

Slight little things that many will question, and the aim is to capture this stuff in Pix so it can be useful.

I may (if time permits) do a live video of the startup procedure and the first run.

As its stands now the goal is to take the mystery out of building a GM diesel

The little things such as how to properly install the pushrods (copper colored ball to the rockers and such) will be shown and discussed.

Loads of lets get dirty fun

MGW
 
Yup
I had the TDP book laying on the paper that the cups were on when I snapped the pix.
I cropped the pix a little to take the TDP stuff out of the pix.

I was looking through the book to see if it contained the article on the precups I was looking for.
 
Figured that it was a tad crass to leave the TDP book in the Pix.

I own the pix and arranged it but dont want to ruffle any feathers ya know.

MGW
 
Just in case someone here does not know it, I am a mod over at the page and spend a fair amount of time there too.
I am sharing the same materials on my build with both forums.

Several folks I know frequent both boards.

So if you see something here that looks Identical to whats next door at TDP, thats why.

MGW/Robyn same same same
 
Last edited:
I was just going ask if you are one and the same.

I just got the bottom end done on mine today. Will be doing the heads soon.
 
Yesss indeed.
Same crazy lady that gets around.

I just discovered that one set of my rings was missing the oil ring expander.

Sealed package and it still managed to get out.

Original GM rings via ebay. Oh well

The seller had a few sets left and is sending a replacement tomorrow.

I just finished getting the pistons installed on the rods.

Eating some late lunch now and will head back down stairs to do a trial fit on the pistons and rods to check the rod bearing clearance.

Once thats done the rings can be checked for end clearance and the assemblies can go in for the final time.

Will definately be happy when this thing is done and back amongst the living breathing and rattling little creatures around here.


Later

MGW
 
davo727 said:
Here is a post that I copied off a sticky thread by maxpf on a certain K5 blazer forum in colorado:




I had to dig around, but I was able to find every (or at least most ) precup part #'s.

Discontinued part #'s

23500082 - 1 dot - 6.2L "C" code - 1982-1990

14525518 - 3 dot - 6.2L "J" code and military - 1982-1990

10149688 - 3 dot with a @ (circle A) - 6.2L "J" code and military - 1990-1992

10163707 - 1 dot with a © (circle C) - 6.2L HD/Commercial - 1992 only


Currently available part #'s

10149630 - "T" - 6.5L "F" code - 1993-1994

10230426 - Square - 6.5L "Y" code (and presumably military) NA - 1994-up

10149629 - Circle - 6.5L "S" code - 1994-up

10183926 - Diamond - 6.5" "F" code - 1997-up


You will notice that there are some holes in the listings. For instance, what cup was used in 1991-1992 "C" code motors? Also, there is no mention of what cup was used in the 1995-1996 "F" code 6.5's, although I believe it was the "T" cup. If anyone can fill in the holes, please do.

Also, the old "fuel economy" 6.2 cups are no longer available. I don't know this for sure, but I would bet the "Y" code 6.5 NA cup would give the best economy out of all the currently available parts (it has the smallest throat out of all the 6.5 cups). The "Diamond" cups are generally regarded as the best for maximum power in turbo apps.
Click to expand...
Not wanting to revive this thread, just adding on.

My 1995 141 "F" engine had the circle or "S" precups in it.
 
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