Mystery Engine Number

john 215 · Post by **john 215** » Mon Mar 07, 2016 7:21 am

Hi,

Been asked by a fella over on a TR7 forum I am on to help I.D a engine number for him, it is -

46A00708A

Its a late 3.9 / 3.5 block with cast crossbolts BUT not tapped, fitted with a SD1 type front cover, you can see that the engine number has been machine stamped into the block and has a compression ratio od 8.13:1 -

Any ideas ???

Cheers John

mgbv8 · Post by **mgbv8** » Mon Mar 07, 2016 8:12 pm

46A is a new one on me John ??

Maybe an export engine??

if you cant find the number on here try the V8 register or even give Rimmer Brothers a call

Perry

ChrisJC · Post by **ChrisJC** » Mon Mar 07, 2016 8:19 pm

Looks unusual. I think 46D is the Range Rover P38 engine....

Chris.

john 215 · Post by **john 215** » Tue Mar 08, 2016 5:35 am

Hi,

Could be a Range Rover lump with that compression ratio and acquired a SD1 front cover along the way. I did ask ' Google ' and Marcos was mentioned in relation to this number, but really cant see them using a 8.13:1 CR can you ??

Cheers John

SimpleSimon · Post by **SimpleSimon** » Tue Mar 08, 2016 12:40 pm

ChrisJC wrote:Looks unusual. I think 46D is the Range Rover P38 engine....

Chris.

I think the owner may be in for a nice surprise rather than the 3.5 he expected

DEVONMAN · Post by **DEVONMAN** » Tue Mar 08, 2016 4:54 pm

SimpleSimon wrote:
ChrisJC wrote:Looks unusual. I think 46D is the Range Rover P38 engine....

Chris.
I think the owner may be in for a nice surprise rather than the 3.5 he expected

I would have thought it would have factory drilled and tapped cross bolts if it was a 4.6 but you never know.

Blown v8 · Post by **Blown v8** » Tue Mar 08, 2016 8:06 pm

Just out of interest,are most of the engines stamped there !
My engine number is on the n/s but at the back near the bellhousing !

mgbv8 · Post by **mgbv8** » Tue Mar 08, 2016 9:09 pm

Blown v8 wrote:Just out of interest,are most of the engines stamped there !
My engine number is on the n/s but at the back near the bellhousing !

Thats where the engine number was stamped on my original 1975 MGB V8 engine which was also 8:1 CR ??

john 215 · Post by **john 215** » Tue Mar 08, 2016 9:10 pm

Hi,

Looks unusual. I think 46D is the Range Rover P38 engine....

Sorry but looking at the picture it says 46A, I think ?

Cheers John

mgbv8 · Post by **mgbv8** » Tue Mar 08, 2016 9:11 pm

Blown v8 wrote:Just out of interest,are most of the engines stamped there !
My engine number is on the n/s but at the back near the bellhousing !

Thats where the engine number was stamped on my original 1975 MGB V8 engine which was also 8:1 CR ??

ChrisJC · Post by **ChrisJC** » Wed Mar 09, 2016 10:18 pm

john 215 wrote:Hi,

Looks unusual. I think 46D is the Range Rover P38 engine....
Sorry but looking at the picture it says 46A, I think ?

Cheers John

Yes it does. I was just thinking that maybe it meant it was of a similar age to a P38 engine (the style of the numbers looks to be the same). I would go with the theory that it is a special number sequence for a small sports car manufacturer, as pointed out above. It's a low number too, so clearly not a volume builder.

Chris.

john 215 · Post by **john 215** » Thu Mar 10, 2016 6:37 am

Hi,

Thanks for the answer,

Was thinking along the same lines myself, just the low compression ratio, unless destined for a foreign market and never made the journey.

Cheers John

Ian Anderson · Post by **Ian Anderson** » Thu Mar 10, 2016 7:20 am

Could it be for a TVR turbo application?
Or is that too high a static compression fora turbo engine?

Ian

DEVONMAN · Post by **DEVONMAN** » Thu Mar 10, 2016 8:44 am

8.13 compression ratio is ok for turbo application.

My Son's sierra has a twin turbo 4.6 with this ratio.

The max boost is controlled at 1 Bar.

Darkspeed · Post by **Darkspeed** » Thu Mar 10, 2016 10:54 am

Could it be just a number for a spares new short block assembly - hence why no list as being associated with particular car.

There were quite a few of these new short assemblies kicking about a while back and may explain all the secondhand parts bolted to it. SD1 cover 14 bolt heads etc.