Info on 57 283 needed

[FWilliams]

hello all, I was told that someone on this site would know the answer to my question, as I have been told a couple of different scenarios.

I am a engine builder in the Seattle area, I currently have a 283 in the shop that came out of a 1957 corvette to be freshened up.

the following data is from the engine

block casting number= 3731548

date code=L-8-6

suffix number on block pad= F55G

the engine has a forged crank # 3815822

it also has a factory windage tray


I have been told that this IS NOT the factory engine for the car as the suffix code is wrong. We are currently trying to determine if it is indeed the correct engine for this car before we continue with the rebuild. the current owner insists that this engine has been in the car since it was new.

thanks for your time and help.

Fred

 

[XLR8]

Fred, I'm sorry I can't help you with your inquiry, but give it some time and we'll have members checking in that are much more knowledgeable on this subject than I.

Welcome to the CAC!
Jane Ann

 

[2X4's 60]

According to Mortec, that casting number is for a 1957 265 or 283. The stamp on the pad indicates that it isn't a Corvette motor.

 

[Bob Willis]

Casting # 3731548 was the only 283 block in 57.


1957 ENGINE SERIAL NUMBER AND SUFFIX CHART.

The 15-21-2400 models are the tin cars, 150, 210 and Bel Air models

TYPE MODEL DESCRIPTION
A 15-21-2400 Regular "235" Engine - 6 Cylinder
AD 15-21-2400 Regular "235" Engine - 6 Cylinder with Heavy Duty Clutch
B 15-21-2400 "235" - 6 Cylinder Powerglide
C 15-21-2400 "265" - 8 Cylinder with 3-Speed Transmission
CD 15-21-2400 "265" - 8 Cylinder with Overdrive
CE 15-21-2400 "265" - 8 Cylinder with Heavy Duty Clutch
E 15-21-2400 "283" - 8 Cylinder with 4BC
EA 15-21-2400 "283" - 8 Cylinder with Dual 4BC
EB 15-21-2400 "283" - 8 Cylinder with Dual 4BC and Hi Lift Cam
EC 15-21-2400 "283" - 8 Cylinder with Overdrive and 4BC
F 15-21-2400 "283" - 8 Cylinder with Powerglide
FC 15-21-2400 "283" - 8 Cylinder with Powerglide and 4BC
FD 15-21-2400 "283" - 8 Cylinder with Powerglide and Dual 4BC
FA 15-21-2400 "283" - 8 Cylinder with Powerglide and Air Conditioning
FE 15-21-2400 "283" - 8 Cylinder with Powerglide, Air Conditioning and 4BC
FJ 15-21-2400 "283" - 8 Cylinder with Powerglide and Fuel Injection
G 15-21-2400 "283" - 8 Cylinder with Turboglide
GC 15-21-2400 "283" - 8 Cylinder with Turboglide and 4BC
GD 15-21-2400 "283" - 8 Cylinder with Turboglide and Duel 4BC
GF 15-21-2400 "283" - 8 Cylinder with Turboglide and Fuel Injection
EJ 15-21-2400 "283" - 8 Cylinder with Fuel Injection
EK 15-21-2400 "283" - 8 Cylinder with Fuel Injection and Hi Lift Cam
EF Corvette "283" - 8 Cylinder with 3-Speed Transmission and 4BC
EH Corvette "283" - 8 Cylinder with Duel 4BC
EG Corvette "283" - 8 Cylinder with Duel 4BC and Hi Lift Cam
FG Corvette "283" - 8 Cylinder with Powerglide and Dual 4BC
FH Corvette "283" - 8 Cylinder with Powerglide
EM Corvette "283" - 8 Cylinder with 3-Speed Transmission and Fuel Injection
EL Corvette "283" - 8 Cylinder with 3-Speed Transmission, Fuel Injection and Hi Lift Cam
FK Corvette "283" - 8 Cylinder with Powerglide and Fuel

 

[FWilliams]

thanks for the welcome and replies.


interesting...that suffix code is not for any type of high performance model at all?, yet this thing is fitted with the correct heads...windage tray...etc..

car has been in the family since new.


are you sure there is only 1 casting number for a 283 in 57?...I believe I have another 283 block in the shop with a casting number of 3949852, that has a date code of 57?


thanks to everybody for your help

hi, Jane Ann



Fred

 

[Tom Bryant]

It's possible that the dealer could have put that engine in the Vette before it was sold new so your customer would be right in his thinking. Imagine if the Corvette engine was damaged and the dealer had many Bel Airs but only one Corvette. So he had the service dept pull an engine out of an inventory car and drop it in the Vette to get it going again. Then he would have ordered a warranty engine for the Bel Air. Sounds far fetched but there has been documented cases of cars being delivered new with non matching engines.

The chance of that engine being installed at St. Louis, however, is none. There would be no reason to even have a G suffix code engine in the plant.

Tom

 

[Mac]

Welcome to the Corvette Action Center!!

Out of curiosity, could you post digital pictures of the engine and the markings? Some of our regulars are NCRS judges and, as the old saying goes, a picture is worth 1000 words. If you don't know how to post pictures, shoot me a Private Message (upper right of your screen) and I'll give you an email addy and post them on your behalf.

-Mac

 

[Bob Willis]

thanks for the welcome and replies.


interesting...that suffix code is not for any type of high performance model at all?, yet this thing is fitted with the correct heads...windage tray...etc..

car has been in the family since new.


are you sure there is only 1 casting number for a 283 in 57?...I believe I have another 283 block in the shop with a casting number of 3949852, that has a date code of 57?


thanks to everybody for your help

hi, Jane Ann






Fred

That sounds like a 58 block . They started building 58s in Sept of 57 so it could have a cast date from 57. 1957 283s are the only 283 without side motor mount bosses. Does it have 997 heads ? I think your 57 had a heart transplant.

Bob

 

[2X4's 60]

are you sure there is only 1 casting number for a 283 in 57?...I believe I have another 283 block in the shop with a casting number of 3949852, that has a date code of 57?

Fred

I don't recall anyone saying that. 3849852 is 57-66 283. I would bet that it has side mounts unlike your other block. Still not applicable to Corvettes.

 

[JohnZ]

The "G" suffix says it was originally installed in a '57 passenger car with a 2-barrel and Turboglide; all Corvette suffixes in '57 were two digits, and started with "E" or "F".

I don't show any block casting number other than 3731548 for '57 283's, in cars, trucks, or Corvettes; the 3949852 casting number wouldn't have been issued until the mid-60's, and I don't show any production usage for it.

 

[FWilliams]

I don't recall anyone saying that. 3849852 is 57-66 283. I would bet that it has side mounts unlike your other block. Still not applicable to Corvettes.

my mistake then, that it how I took this reply, sorry.




Fred



Bob WillisCasting # 3731548 was the only 283 block in 57.


1957 ENGINE SERIAL NUMBER AND SUFFIX CHART.

The 15-21-2400 models are the tin cars, 150, 210 and Bel Air models

TYPE MODEL DESCRIPTION
A 15-21-2400 Regular "235" Engine - 6 Cylinder
AD 15-21-2400 Regular "235" Engine - 6 Cylinder with Heavy Duty Clutch
B 15-21-2400 "235" - 6 Cylinder Powerglide
C 15-21-2400 "265" - 8 Cylinder with 3-Speed Transmission
CD 15-21-2400 "265" - 8 Cylinder with Overdrive
CE 15-21-2400 "265" - 8 Cylinder with Heavy Duty Clutch
E 15-21-2400 "283" - 8 Cylinder with 4BC
EA 15-21-2400 "283" - 8 Cylinder with Dual 4BC
EB 15-21-2400 "283" - 8 Cylinder with Dual 4BC and Hi Lift Cam
EC 15-21-2400 "283" - 8 Cylinder with Overdrive and 4BC
F 15-21-2400 "283" - 8 Cylinder with Powerglide
FC 15-21-2400 "283" - 8 Cylinder with Powerglide and 4BC
FD 15-21-2400 "283" - 8 Cylinder with Powerglide and Dual 4BC
FA 15-21-2400 "283" - 8 Cylinder with Powerglide and Air Conditioning
FE 15-21-2400 "283" - 8 Cylinder with Powerglide, Air Conditioning and 4BC
FJ 15-21-2400 "283" - 8 Cylinder with Powerglide and Fuel Injection
G 15-21-2400 "283" - 8 Cylinder with Turboglide
GC 15-21-2400 "283" - 8 Cylinder with Turboglide and 4BC
GD 15-21-2400 "283" - 8 Cylinder with Turbog

 

[2X4's 60]

I guess I should have read the replies more carefully. My info. came from mortec.com. I would trust what John Z. says.

 

[FWilliams]

thanks a ton guys, I really appreciate the wealth of knowledge .

I have come to the conclusion that the block has been changed, using all the previous internals. the crank and windage tray would not have been in a turboglide block...I do quite a bit of work on Gen 1 SBC and am familiar with the turboglide crank.


I though possibly , and was told by someone that it might have been done at the factory end.

but like Tom Bryant said, the chances of it being installed at St, Louis are none.......that is good enough for me to put it to bed.


I hope I can repay the help in some way...like I said I do lot of Gen 1 stuff so maybe I can help in some way.

thanks so much for the info,

Fred

 

[Bob Willis]

When you build the engine for the 57 make sure you have the spacer to move the balancer out the width of the front mount bracket so that the crank and water pump pullies line up when you are finished. Passenger car engines don't have the spacer.

Bob

 

[Tom Bryant]

Glad that we could help Fred. You are welcome to stop by and visit anytime.

Tom

 

[vettefinderjim]

The "G" suffix says it was originally installed in a '57 passenger car with a 2-barrel and Turboglide; all Corvette suffixes in '57 were two digits, and started with "E" or "F".

I don't show any block casting number other than 3731548 for '57 283's, in cars, trucks, or Corvettes; the 3949852 casting number wouldn't have been issued until the mid-60's, and I don't show any production usage for it.

The 3849852 block was used in 1964-1966 Chevelles., It is a two bolt main block, but can be modified for 4 bolt.

If you give the vin number of the car........and the casting date number of the 548 block, i can tell you if it is correct for the Corvette as far as time build. ONLY 3731548 blocks were used in 1957 CORVETTES. And they must be FLINT, MICHIGAN made at the Saginaw, MI foundry.

Heads should be 3740997 for all engines except 283hp fuel injection which used 3731539.
The later 539 heads were also used a four barrel 283 powerpack engines for passanger cars.

 

[Bob Willis]

The 3849852 block was used in 1964-1966 Chevelles., It is a two bolt main block, but can be modified for 4 bolt.

All 283s were 2 bolt mains.

 

[Cruzen]

Here’s a scenario for you all to ponder. In 1973 I ordered a Chevelle with a 454, 4 speed and posi. I won’t bore you with the details but after nearly six months when it came in it had neither the engine or trans I had ordered. I refused to take the car so after several days of calling me and negotiating, to make the deal happen the dealer agreed to put a “Corvette” engine into the car.

In the shops at that time they had a new Vette with spun bearings. GM had approved a whole new engine but due to the fact that the L-82 was new that year the dealer had trouble getting the replacement engine. Instead the dealer dropped the crank, cleaned it up and installed new bearings and put the Vette back on the road. Shortly after the new L-82 engine arrived and that is what went into my 1973 Chevelle. It was fully warranted by Chevy. Over the years I had several dealers who told me this had not happened. I would then pull the car into their shop and prove it along with the work order. If some such had been done to a Corvette would it be considered “Original”?

Current threads made me wonder about this.

Denny

 

[JohnZ]

If some such had been done to a Corvette would it be considered “Original”?

Current threads made me wonder about this.

Denny

No, it wouldn't. The judging standard requires the engine to have the correct casting number, casting date, and front pad with the correct engine plant date and usage suffix stamping, and assembly plant VIN stamping and the correct pad surface; it must appear to be the engine installed at St. Louis.

 

[CNC BLOCKS]

I have one of those 283 blocks in the shop with no motor mounts and I believe its a 57 block and its been cleaned and magged does any one know what its worth????