BDG?

[Peter T]

I am currently deciding on buying a 260bhp BDG unit, although i am pretty clued up on the various BD series engines, i need to know if there are any real external differances in size, or configeration. I think it is an iron block but this has not been confirmed yet, are there big changes if the unit turns out to have a Brian Hart block of 2ltrs plus? Any information asap will help me, as i need to make a decision (and a very expensive one at that!) Also having just missed one.

Thanks.

 

C7 PWT X-Flow all Steel

Life begins at 40(00rpm)

[Taran Las]

Someone will correct me if I'm wrong but I thought BDGs had an aluminium block.

 

Philip. D. Owen

Membership No.id=red> 3976id=blue>

[Roger King]

Everybody refers to the aluminium block version as a BDG, but in fact this refers to the rare iron block version.

 

If you end up with a Hart block, it may well have chrome plated bores instead of liners. This is going to cause MAJOR headaches if you need to do any work on the bores.

 

Personally, I would never buy a BD of any variant unless one of three conditions was met:-

 

1) The seller knows who built it and you can contact him. If he can provide details of that individual engine and he has a good reputation, it is probably OK. If it becomes obvious that he doesn't have a record of that engine in great detail, (provenance, what was replaced at last rebuild and why, history of all major components, etc), walk away. In our experience, over 90% of BDs that are brought to us after secondhand purchase are basket cases, despite all the claims of 'freshly rebuilt', etc.

 

2) You are able to inspect the engine in a dismantled state and there is no objection to crack testing etc - nearly all steel cranks that have been reground prove to be cracked in our experience. Typically, this happens when a big end runs and the crank is then ground to clean up the damage, but no-one thinks to crack test. You should also crack test conn. rods, pistons, cam carrier, cams, block, etc. NOTHING on these engines is cheap to replace.

 

3) It is a BDR supplied by Caterham and it has not been touched by any since (unless condition 1) applies).

 

Not trying to be a pessimist here, because BDs are fabulous. It's just that most have a competition background and are often bastardised from 'bits of this and bits of that' by the time they are on the third owner and he needs to rebuild on a budget.

[Peter T]

Thanks for the info Roger, does this include a engine from a repiatable engine builder?

 

C7 PWT X-Flow all Steel

Life begins at 40(00rpm)

[ross]

peter

i have a 2.0 alloy "bdg" - which i call a bdg cos it matches the number plate - even if the engine build sheet says 2.0 bda!

i think roger king's advice is spot-on - it is worth doing homework - as mistakes can be costly. I would be surprised if there is not also a dated build sheet with spec from engine aswell - which would make life easier if you need to get your hands dirty at some stage.

 

on a positive note - although i do not use my car as much as i would like - it makes an excellent engine for a 7 - even with L1's quite tractable - especially on injection - and at 5250 - a real buzz as the engine comes on cam...doesn't sound that bad either

 

reliabilty wise - admittedly with low usage - i have had no problems with the engine - touch wood - only thing you need to replace on a regular basis is rear tyres!

[Roger King]

Peter,

 

If the engine builder is reputable and experienced with this type of engine (and there aren't many), he will have records of what has been done, when and why. This would then fulfil condition 1) above. If there is any doubt at all I wouldn't commit my money.

 

Having said all of this of course, somewhere there will be a bargain lurking.

[Peter T]

Thanks for the avice Roger, you are quite right in that there should be some form of history with any serious engine, i am glad that i missed the previous unit , as it had no history with it, and the guy would not let me view the bootm end! Roger if you know of any good engines that need a home , please dont hesitate to call me.

 

C7 PWT X-Flow all Steel

Life begins at 40(00rpm)

[edmandsd]

There were a few 'Ashcroft blocked' BDG's which used a special iron block to give 2 lt's without increasing the stroke.