MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGA - replacement engine

I have a 1958 MGA 1500 roadster which I have owned since 1976. The installed engine is from a Magnette with a typical K series number plate and I had this motor rebuilt in 1977. It's a great runner. I have always wanted an original motor with the mechanical tachometer (the significant difference in the motors). I will be placing this motor for sale sometime after the replacement project is complete. In 1994 I was able to procure an original A block with parts such as pressure plate, clutch, water pump, back plate, valve cover etc. I wanted to get opinions on the matter of matching numbers and having new plates made with the replacement engine number. The replacement motor is from the same batch of production from the original stamped motor number. Is this important? Is it ethical to place new plates in the car and claim it has matching numbers? The replacement motor has just been rebuilt by Joseph Siam at Chequered Flag motors in Chatsworth, California. I will be following up with other threads and seeking advice from the community about the project and preparing and installing the new motor. Safety Fast!

Stephen Lofaro
Simi Valley, CA
Stephen Lofaro

It would not bother me one bit,but I can see where some would object. It makes it difficult because being a 1500 you know by the plate what it should be. 1600's like mine on the other are not recorded. Can I be sure mine has never been changed? 100% if I was the original owner but I am not. This is a decision only you can make,but I would change the engine plate to what the chassis plate says. If you go to sell or if someone asks you would have to be up front,and it might be wise to document your change and keep it with the rest of your paper work. I think you would be surprised how many,and not just MG's, are not what they seem, especially in high dollar muscle cars.
gary starr

I agree pretty much with Gary. Of course, if it is done with the deliberate intention to deceive, then it is fraud. If any of the original engine remained it could be argued that some engine components (including the block) have been exchanged with like for like replacements, but the original number has been retained.

Certainly, while it may appear to be a matching numbers car, to claim it to be is morally and legally wrong. To be up front or to remain silent is a legal and moral dilema. To use the number from the new engine, or not to have a number at all would give me the best sleep!
N McGurk

Stephen

My 1958 1500 maker's plate (ex USA export California car) does not give an engine number. Like the later 1600s it also simply says 'See Engine'. Only very early 1500s had the engine number on the maker's plate. So, I am intrigued that you say "The replacement motor is from the same batch of production from the original stamped motor number".

Is that stamped number on the maker's plate? If so it is likely that the plate is not original; or is the plate you are referring to the engine number plate that has been removed from the block of an old engine? Which begs the question, was that engine original?

Steve
Steve Gyles

1 "The installed engine is from a Magnette with a typical K series number plate"
>> What does that mean? No Magnette engine number starts with or includes a "K". In fact, no BMC power unit number includes a "K". "K" is the starting character for Magnette CAR numbers, and is used in several other places in CAR numbers to denote various things. These DO NOT appear on the engine ID plate.

2 " (the significant difference in the motors). "
<< IF it IS a Magnette engine, and is early enough, there are MUCH more significant differences. SURPRISE - Engines are NUMBERED to track such differences. If it now has a plate with a "K", then you have no clue as to what it did come in or what it really IS, only that it was NOT an MGA (by the no tach).

3 "The replacement motor is from the same batch of production from the original stamped motor number."
>> And you determined this how? Given that you do not seem to have the original engine. Does the new engine come with a number plate reasonably believed to be accurate?

4 "Is it ethical to place new plates in the car and claim it has matching numbers?"
>> No more than any other attempt at lies and obfuscation. And it really pisses mechanics off when they order parts and make plans based on false numbers anywhere.

5 "To be up front or to remain silent is a legal and moral dilema. "
>> Not here. Simple question, simple answer.

I hate it when I get engines with no plates; it requires defective work which takes hours or days and sometimes cannot be resolved.

In some cases extremely significant differences in engines or other components are denoted only by number, and cannot be discerned other than by extreme familiarity, research, and reference materials. People who ask these questions are clearly NOT competent to say "all 1500 are the same" or whatever, and then go swapping plates. Do Not Attempt to work on Rover with this attitude!

I have at times made replacement plates to replace damaged originals, or to record what I have figured out about an engine, while clearly indicating that it is NOT the original item. Like "15GA ????", maybe as a brass plate rather than aluminum; copies of damaged but certain OE plates may be duplicates.
I also stamp any machining differences on the parts and on an attached plate, As:
B +.030 D -.027
H -.043 24.2cc
M -.010 R -.020,
Piper 270 In.017 Ex.019
If this data is subsequently altered, I cross out the old and restamp the new info. Sometimes the sequence is important at a later date. If you are going to play with historical things, treat them as a historian, or as a Doctor would.

FRM
FR Millmore

Interesting comments so far, thank you. The engine plate on the motor that is in my car now should have correctly been identified as 15K 926. It is a 1500cc motor and looks very similar in all respects to the MGA block with the exception the mechanical tach port is blanked out. The previous owner told me it was from a Magnette. I am now not sure what type of car it was manufactured for as I have been searching on the internet and could not find it, so far. Does anyone have a notion as to what car this motor (15K 926) was made for??

The plate on the heater shelf of my MGA reads Engine No. BP15GB 23586. Chassis Number HDT 43/33370.

The 'new' rebuilt engine that I am going to install is original MGA 1500cc and the engine number reads 15GB 19276 and I do believe it to be accurate as it was on the engine when I got it in 1994 and looks to have never been touched and no signs of removal or replacement on or near it on the engine block.

FR asks how do I know they are from the same production run...let me refer you to MGAguru.com which is an excellent resource for the cars and there is a memo entitled "Production Changes for MGA-CF-125". In fact it states the engine number changes from BP15GB designation to 15GB-U-H began at approximately engine number 23000. So even though my engine is 23586 it still retained the identification from the earlier run. That is how I came to my conclusion that in most respects they are very nearly the same type of engine with the possible modification of the valve guides and the thickness of the valve cover seal as noted in the memo.

In any case, I am going to replace the engine and put a new identification plate that has the new matching engine and chassis number with the it. I intend to keep the original identification plate as part of the history of the car, no question about that. I just want to restore this car to a true MGA and it is finally happening. I figure that since Clark Spares in Pennsylvania offers this service with proper VIN proof then I will do it. More to follow and thanks for the interest so far. I am sure to have a 'few' more questions for all.

Stephen
Stephen Lofaro

Stephen

Your chassis number dates the car to about June 1957.

Steve
Steve Gyles

Stephen

The only data I can find about the engine number being printed on the manufacturers plate refers to 'early 1500s'. If your engine plate is original then it gives a clue that it was still being included until at least June 1957. Certainly by the time my car was produced in August 1958 the plate said 'See Engine'.

Steve
Steve Gyles

Your engine number is definitely not from a Magnette. Looking at Neil Cairns' engine history book(http://www.mgexperience.net/article/mgenginehistory.html) the MGA ZA had a BP15GA, the ZB BP15GC Magnette Mk3 15GE and Mk4 16GE or 16GF.

I agree with FRM, you should keep the engine number on the engine. Anything else will just cause trouble in the future.
Dan Smithers

As my comments on Stephen's parallel thread if BMC themselves changed engine number on reconditioning to the '48G' series surely it is possible some other unidentified reconditioner did the same using the 15K series.

Paul
P M Dean

It is more likely that the "K" denotes some non-BMC application, which were numerous, but poorly documented. Most likely are Nash/Austin Metropolitan, IH Metro van, certain forklifts, Ditch Witch or similar excavators, boats, tractors. I have recently been involved in a discussion of very odd 1600 versions of these, and have inquiries out. (1600 was MGA only, but some strange ones have turned up.)

FRM
FR Millmore

FRM makes a very good point here. I had heard that there were non BMC uses for these engines in tractors and even as generators and elevator room power plants during the war! I will be curious to hear what your inquiries turn up.

I did review the engine histories and I feel lucky that the engine I got is within 4000 from the original that was in my car and on the earlier side of that serial. A true early engine likely fitted to the '57's and early 58's (APPROX).

I will take a photo of the engine and post it soon, Mike.

Stephen
Stephen Lofaro

And what war would that be Steve,the B series was designed after ww2 ;)
gary starr

This thread was discussed between 15/10/2012 and 17/10/2012

MG MGA index

This thread is from the archives. Join the live MG MGA BBS now