Some of you will have read previous threads. I have taken inspected the parts of the original block in my 79 vette. After removing the carbon on the piston tops, I found partnumber 3959456. These are domed pistons. What was the original intention of these pistons? They seem fairly high CR pistons (in the region of 11/1).
Could these be original L82 type pistons or are we talking about something else?
PS: one of the bores has some traces of rust in them, so I guess I'll be in for a rebore and o/s pistons.
pistons GM 3959456
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Re: pistons GM 3959456
I believe the L82 engines came with forged flat-top pistons. The 350 LT-1 came with forged pistons which had a small dome.Belgian1979 wrote: ↑Sun May 09, 2021 10:15 am Some of you will have read previous threads. I have taken inspected the parts of the original block in my 79 vette. After removing the carbon on the piston tops, I found partnumber 3959456. These are domed pistons. What was the original intention of these pistons? They seem fairly high CR pistons (in the region of 11/1).
Could these be original L82 type pistons or are we talking about something else?
PS: one of the bores has some traces of rust in them, so I guess I'll be in for a rebore and o/s pistons.
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Re: pistons GM 3959456
That's what I found: that these were 70-71 LT1 pistons. Hm, quite strange that these ended up in my engine combined with the 292 heads.
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Re: pistons GM 3959456
Belgian1979 wrote: ↑Sun May 09, 2021 10:48 am That's what I found: that these were 70-71 LT1 pistons. Hm, quite strange that these ended up in my engine combined with the 292 heads.
Sounds like a dealer had a special engine put together using factory parts for his own car.
http://www.rmcompetition.com
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Re: pistons GM 3959456
Polish the bores with the 400 wet-or-dry trick and see if the rust may be no problem. Shine it up, put the old pistons and rings back in it and run it.Belgian1979 wrote: ↑Sun May 09, 2021 10:15 am Some of you will have read previous threads. I have taken inspected the parts of the original block in my 79 vette. After removing the carbon on the piston tops, I found partnumber 3959456. These are domed pistons. What was the original intention of these pistons? They seem fairly high CR pistons (in the region of 11/1).
Could these be original L82 type pistons or are we talking about something else?
PS: one of the bores has some traces of rust in them, so I guess I'll be in for a rebore and o/s pistons.
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Re: pistons GM 3959456
The decks also have some surface rust (not sure if it is pitted into the deck? Block sanding it?Tuner wrote: ↑Sun May 09, 2021 5:27 pmPolish the bores with the 400 wet-or-dry trick and see if the rust may be no problem. Shine it up, put the old pistons and rings back in it and run it.Belgian1979 wrote: ↑Sun May 09, 2021 10:15 am Some of you will have read previous threads. I have taken inspected the parts of the original block in my 79 vette. After removing the carbon on the piston tops, I found partnumber 3959456. These are domed pistons. What was the original intention of these pistons? They seem fairly high CR pistons (in the region of 11/1).
Could these be original L82 type pistons or are we talking about something else?
PS: one of the bores has some traces of rust in them, so I guess I'll be in for a rebore and o/s pistons.