Non-matching numbers engine
Thread Starter
Racer
Joined: Jul 1999
Posts: 273
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From: Murphy Texas
Non-matching numbers engine
As I try to learn more, I think I've just found out that my engine is not original on the 77 L-82 I bought.
The VIN# indicates it is an L-82 (1Z37X7S412105)
The engine block # is 3914678, which is one of the following:
Block # Size Year Main Cap Bolts Notes
3914678....302.....68...............2... ............Z-28 Camaro
3914678....327.....68...............2
3914678....350.....68...............2
So, based on this, it looks like the engine is from 1968 (if I understand this right). The question is, which one? I'm assuming it is the 350, but how can I tell for sure?
Since the VIN indicates it was an L-82 originally, which was 210 HP, how can I find out about what this engine performance is? I may change it out to a ZZ4 down the road, but in the mean time I'm looking to play around with this one.
As you can tell, I'm a rookie trying to learn the ropes here.
:smash:
Thanks guys!!
Greg
The VIN# indicates it is an L-82 (1Z37X7S412105)
The engine block # is 3914678, which is one of the following:
Block # Size Year Main Cap Bolts Notes
3914678....302.....68...............2... ............Z-28 Camaro
3914678....327.....68...............2
3914678....350.....68...............2
So, based on this, it looks like the engine is from 1968 (if I understand this right). The question is, which one? I'm assuming it is the 350, but how can I tell for sure?
Since the VIN indicates it was an L-82 originally, which was 210 HP, how can I find out about what this engine performance is? I may change it out to a ZZ4 down the road, but in the mean time I'm looking to play around with this one.
As you can tell, I'm a rookie trying to learn the ropes here.
:smash:
Thanks guys!!
Greg
Safety Car
Joined: Jun 2002
Posts: 4,844
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From: Pearland TX
St. Jude Contributor
Re: Non-matching numbers engine (USA SHARK)
USA SHARK,
There should be a date code above that block casting # in the back. Something like A26 72. The above example is off of my 355 in my '74 which is a '72 block. That should give you a better idea of what is in your vette. Have you pulled the valve covers to get the numbers off the heads yet?
And what's the serial # on the front pad on the passenger side of the block? It might be painted over, but that will give you more information than anything about it. And then again... if someone resurfaced the cylinder head surface it might have been removed.
[Modified by bgrice, 7:48 PM 8/22/2003]
There should be a date code above that block casting # in the back. Something like A26 72. The above example is off of my 355 in my '74 which is a '72 block. That should give you a better idea of what is in your vette. Have you pulled the valve covers to get the numbers off the heads yet?
And what's the serial # on the front pad on the passenger side of the block? It might be painted over, but that will give you more information than anything about it. And then again... if someone resurfaced the cylinder head surface it might have been removed.
[Modified by bgrice, 7:48 PM 8/22/2003]
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 2
From: New Zealand
Re: Non-matching numbers engine (USA SHARK)
There's a four digit block casting date...e.g. F272....usually at the back on the passenger or drivers side....could be near your block casting number.....
Also, on the front passenger side of the block, just below the heads, is a stamped engine suffix code and partial VIN.......but it won't be there if the block's been milled.....
You can remove your valve covers to get the head casting numbers and date codes....
If all these numbers are there and line up....you may be able to narrow it down to what car it belonged to.....but really the fastest way to find your torque/HP #'s is to put it on a dyno.....
....post the numbers here for help in decoding.....
Also, on the front passenger side of the block, just below the heads, is a stamped engine suffix code and partial VIN.......but it won't be there if the block's been milled.....
You can remove your valve covers to get the head casting numbers and date codes....
If all these numbers are there and line up....you may be able to narrow it down to what car it belonged to.....but really the fastest way to find your torque/HP #'s is to put it on a dyno.....
....post the numbers here for help in decoding.....
Thread Starter
Racer
Joined: Jul 1999
Posts: 273
Likes: 0
From: Murphy Texas
Re: Non-matching numbers engine (standup)
OK... I went back and checked for the additional numbers and here is what I found:
Just above the block # is 8GM (That's all I could see)
In the front on the passenger side, there were two sets of numbers:
18J267091 V0507HH
Thanks for all of your help everyone! Someday I will learn :yesnod:
Just above the block # is 8GM (That's all I could see)
In the front on the passenger side, there were two sets of numbers:
18J267091 V0507HH
Thanks for all of your help everyone! Someday I will learn :yesnod:
Drifting
Joined: Feb 2000
Posts: 1,607
Likes: 0
From: Clarksville,Tn,USA TN
Re: Non-matching numbers engine (USA SHARK)
This site here http://www.mortec.com will show you where to look for all the info you will need. I have a 1969 block in my 78 corvette which is cool with me. They had a better nickel content back in the day. As you motor, my casting could of been for a 302 Z-28 or 350 application which it was. Now it is stroked to 388ci and fitted with TFS aluminum heads.
Neil in Tenn
Neil in Tenn
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 2
From: New Zealand
Re: Non-matching numbers engine (USA SHARK)
I think 8GM is generic and on all blocks.....it's definitely not the date code...which is 4 digits.....starting with a letter followed by three numbers.....
18J267091 is:
1 = GM; 8 = 1968; J = Janesville Plant (for assembly of the car/truck...they make Chevy Tahoes now) 267091 = production number (this number should match up with the last six digits of your VIN from the pillar...obviously it doesn't)
V0507HH is:
V=Flint (assembly of motor); 05=May; 07=7th day; HH=300hp 350ci 1969(?) full size....
Finding the block date code will confirm that this is a '68 motor........ :seeya
18J267091 is:
1 = GM; 8 = 1968; J = Janesville Plant (for assembly of the car/truck...they make Chevy Tahoes now) 267091 = production number (this number should match up with the last six digits of your VIN from the pillar...obviously it doesn't)
V0507HH is:
V=Flint (assembly of motor); 05=May; 07=7th day; HH=300hp 350ci 1969(?) full size....
Finding the block date code will confirm that this is a '68 motor........ :seeya
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Safety Car
Joined: Jun 2002
Posts: 4,844
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From: Pearland TX
St. Jude Contributor
Re: Non-matching numbers engine (standup)
Good stuff standup.....
Here's where you should be able to find the block date. It's not easy to read unless you clean it up. Again... on the back towards the top of the block above the casting # on the driver's side.
Here's where you should be able to find the block date. It's not easy to read unless you clean it up. Again... on the back towards the top of the block above the casting # on the driver's side.
Race Director
Joined: Apr 1999
Posts: 15,133
Likes: 477
From: NM
Re: Non-matching numbers engine (USA SHARK)
That HH suffix was used three times. First in 1965 as a 327ci/365hp in the Vette, second in 1966 as a 327ci/300hp also in the Vette, and lastly in 1969 as a 350ci/300hp with automatic in the full size Chevy.
tom...
tom...
Thread Starter
Racer
Joined: Jul 1999
Posts: 273
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From: Murphy Texas
Re: Non-matching numbers engine (Tom73)
That's great info guys! Thanks :thumbs:
I can't see a date where indicated, but I'll try to clean it up later this morning and see if it is there. By the sounds of it, it is likely the 350/300hp engine. Even though it's not "matching" and is supposed to be an L-82 engine, this one might not be a bad substitute :)
I knew when I bought the car it likely wasn't numbers matching. That's not a big deal to me as I wanted something to learn and play with.
I took a couple of pics. Not sure if this will help. The only other numbers I could find were just above the oil filter:
944
657
76
(Pictures below)
I know there were different ways to measure HP, so putting the L-82 up against the 350/300 (assuming that is what it is), what would the matchup look like?
Thanks again everyone! :cheers:
[Modified by USA SHARK, 6:56 AM 8/23/2003]
I can't see a date where indicated, but I'll try to clean it up later this morning and see if it is there. By the sounds of it, it is likely the 350/300hp engine. Even though it's not "matching" and is supposed to be an L-82 engine, this one might not be a bad substitute :)
I knew when I bought the car it likely wasn't numbers matching. That's not a big deal to me as I wanted something to learn and play with.
I took a couple of pics. Not sure if this will help. The only other numbers I could find were just above the oil filter:
944
657
76
(Pictures below)
I know there were different ways to measure HP, so putting the L-82 up against the 350/300 (assuming that is what it is), what would the matchup look like?
Thanks again everyone! :cheers:
[Modified by USA SHARK, 6:56 AM 8/23/2003]
Race Director
Joined: Apr 1999
Posts: 15,133
Likes: 477
From: NM
Re: Non-matching numbers engine (USA SHARK)
Just as a guess I think you may just have a replacement block. Check the head numbers, under the valve covers, and the intake number. Could have the top end of the L82 on the 350/300 block.
Remember, the L82 was rated at NET HP and the 68/69 engines were rated at GROSS HP.
tom...
Remember, the L82 was rated at NET HP and the 68/69 engines were rated at GROSS HP.
tom...
Le Mans Master
Joined: May 2000
Posts: 6,493
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From: Bloomington MN
Cruise-In II Veteran
Re: Non-matching numbers engine (Tom73)
The L-82 would be almost identical to the L-46. The L-46 is the 350/350. About the only real difference is that the L-46 ran 11:1 compression, so they maybe made slightly more power. All the internals are the same and the cam grind is basically the same. The ZQ3 (base motor from 69) ran 10.25:1 compression and a milder cam. Judging by your valve covers (which could be wrong), you have an L-46. The ZQ3 came with painted stamped steel valve covers.
