Rebore but to what size?

[Drogo]

Sorry if this is all rudimentary but just going through the paperwork of my newly acquired 1970 MGB and found this.

Where it says 4x Pistons 1/33.38 how would that relate to new bore and engine capacity?
Also does it show hardened valve seats and guides for unleaded?

[Lotobear]

Post this on engines and drivetrain with MGB in the title and peter burgess will provIde the answers

[Drogo]

Cheers

Not sure how to move so will try to repost.

[mog1275]

I think that is just individual price , same with the valves

[Drogo]

Well done, didn't think of that.

Still be nice to know by how much to CC increased but just there's no easy way?

[InitialDave]

I think unless you remove the head and measure it, you can't really be sure - "rebore" rather than "overbore" says to me it's for the purpose of cleaning up the cylinders, and so removing as little as necessary to do so, but of course, how much that is would depend on if there was any really deep scoring.

[Drogo]

Yea that's along the lines I have been thinking.

I don't feel she needs any more horses as she's nippy enough for a 50 year old.

Got to say I love the drive compared to my previous Honda S2000

[tr7v8]

A trick on MGBs used to be to overbore & use I think Lotus Ewin cam pistons. Gab around 1950cc from memory.

[Skyedriver]

mog1275 said:

I think that is just individual price , same with the valves

Yes agree.
Rebore could be +20 if it was just a clean up or +60 if you wanted to take it out a bit more.

[lowdrag]

Skyedriver said:

Yes agree.
Rebore could be +20 if it was just a clean up or +60 if you wanted to take it out a bit more.

A standard rebore would be +20 thou but then, this is a 1995 bill for a 1970 car, so it might not be the first, so could also be +40 thou. As said, these are just the parts prices. Labour is another matter but back then it wouldn't have been that dear. Whatever, I hope the car gives you miles of smiles.

[mph]

What's the mileage on the car, has it been modified by the previous owner ?

If it's a relatively standard car with a high (ish) mileage, the chances are it was a routine rebuild and the rebore was to 20 thou.

[Drogo]

Good point.

Clock currently shows 36K.
Mot history starts 2006 at 29k then goes steadily up with only a one year gap.

From paperwork I was given with the car and have photos from 1994/5 of the heritage shell swap.
Also have lots of invoices for parts from nuts/bolts to larger stuff but only that one invoice for engine work.

P.S Love the car and glad to be able to now get out in it.

[Skyedriver]

If you happen to have the head off, it'll be stamped on the piston crown. Bit drastic though.

[droopsnoot]

Skyedriver said:

If you happen to have the head off, it'll be stamped on the piston crown. Bit drastic though.

True, but cheapo USB inspection cameras on eBay are under a tenner and would fit through a spark plug hole, and would probably work for long enough to inspect the top of one piston.

[Drogo]

👍I’ve got one and have been thinking that might work.
Not sure I’m that worried, plus might not like what I see.

[Church of Noise]

Well, if ever you feel you want a bit more umph, you could consider getting a head that was flowed by Peter Burgess ( http://www.peter-burgess.com/ - happy customer here and would advise an Econotune head for decent improvement in output for normal driving without loss of torque).
You could use it as an excuse to take the head off

[Lotobear]

Church of Noise said:

Well, if ever you feel you want a bit more umph, you could consider getting a head that was flowed by Peter Burgess ( http://www.peter-burgess.com/ - happy customer here and would advise an Econotune head for decent improvement in output for normal driving without loss of torque).
You could use it as an excuse to take the head off

Peter is the man, and a true gent - I mentioned him at the top of this thread.

He set up my Elan on his rolling road and the results were superb, he really knows what he's doing

[Drogo]

I did check out his website only to see he had an 1860 engine for sale. Was tempted.
Just checked again and it's now SOLD.

Will keep him in mind maybe for another time.