Engine number help

[AndyW123blue]

Hi
I'm trying to identify my engine cc and which model it came from. It's registered as a 1998cc which potentially from looking round isn't correct. The car is a 1968 mk1 gt6 the engine number is cp25784HE I'm ordering overhaul parts soon and don't want to get the wrong ones.


Thanks
Andy

[yorkshire_spam]

Tr5/tr6 pi?

[AndyW123blue]

Is it a 2.5?

[yorkshire_spam]

Yeah I think so.

[WIMPUS]

Like Sam says above !

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[thescrapman]

It could be a TR6 block with a 2000 crank fitted, but most likely it is a 2.5.

Look for dents in the sump above the rack where the crank needs extra space

Cheers

Colin

[AndyW123blue]

I'll have a look when I take the engine out, looking online the engine number looks to be between 68 and 69 the car was registered in 68. Is it likely that someone's changed it or could it of come from the factory with it in.

[Nick Jones]

No, it's been changed.  GT6 would be KE prefix.

Block at least is from a Mk1 PI saloon, TR5 or early-ish TR6.  Could well be a 2.5 and even in a decent state of tune if in original trim to match the "CP" prefix.

Could also be a 2L rebuilt with a donor block after dropped thrust washers or similar disaster though this is perhaps less likely.

Nick

[andy thompson]

February or March 1969 TR6 150hp engine - almost the same number as mine - IF original it's basically a TR5 engine - X drilled crank etc  

[Jonny-Jimbo]

I'll take a punt on it if you end up swapping the engine - could be a good one to go in my Mk1 2000 estate if it is a 2.5 engine.

[AndyW123blue]

Ok thanks everyone, I'll keep you in mind if I change the engine. Can anyone just summarise what the difference is between the 2ltr and 2.5 (apart from the .5) is the block the same?

[Jonny-Jimbo]

As a rule the block is the same, but the head and pistons changed, as well as the crank and cam, and it's age dependent too etc. It's all about as clear as mud until you get into the engine to see exactly what you have. If the pistons are domed it's a 2L, if they're flat it's a 2.5L... probably.

[RobPearce]

If you've got the head off (so that you can see whether the pistons are domed) then you can tell the difference absolutely by measuring the stroke. Turn the crank until one pair of pistons are at BDC and measure how deep they are. Three inches (76mm) means it's a 2L while nearer four (95mm) is a 2.5

[AndyW123blue]

Thanks, this is my first triumph restoration. Must admit the engine is a bit of a mystery still. I'll strip it down then talk to canley or Rimmers to make sure I get the right parts. Does anyone know where I can get a triple weber manifold for this engine I want to fit dcoe 40s

[Richard B]

Was it already fitted to the GT6? If so what induction system did it come with?

Don't let that crank out of your sight. Make sure the oilways are thoroughly cleaned if you have it reground.

Triple twin chokes 🤔  what that engine was designed for, was a set of triple throttle bodies and a Lucas PI metering unit 😎

[AndyW123blue]

Yes it was in the car I bought. It has two strombergs

[AndyW123blue]

Twin strombergs I guess they'll be 150's

[GT6 1]

The correct engine prefix for yours should start KC, KE is Mk III. 🙂