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View Full Version : 2.25 Diesel cam.



dandlandyman
15th April 2013, 01:43 PM
This should make only a short thread, but here goes...

I was recently offered a busted 2.25L diesel from a Series 3. The block is totally scrap as there is a hole in the block which displays Number 1 and 2 cylinders, and the water pump and longitudinal water gallery are smashed open. However, there are no broken pistons or rods and the head is untouched.

I'm interested as, not so long ago, someone mentioned that if you fit a diesel camshaft to a 2.25 petrol, the engine becomes a noticeably 'torquier' unit. I haven't experienced a 2.25 set up this way, though, so I don't know if it actually does this. And what are the drawbacks? Does it use more fuel? Does it run hotter? Does it make the idle rougher? How does it affect the ignition timing? Does it reduce the horsepower?

Of course, I will probably use the crankshaft later, too, when I rebuild my spare engine, as the diesels have forged cranks. My engine is an 8:1CR suffix A 2.25 in a 2A SWB, and I will be fitting a set of extractors to it later on.

Any advice would be greatly appreciated.

Dan.
69 2A 88" pet4 (still in disguise), 68 2B FC pet6 (still resting quietly), plus 14 other project/parts cars (1xS2, 6xS2As, 7xS3s).

schuy1
17th April 2013, 05:31 PM
Do not have any idea on the cam, but I have been told using the diesel pistons in a petrol makes for an engine that 'Holds on" a lot better due to the added inertia of the heavier pistons.

Cheers Scott

dandlandyman
27th April 2013, 12:15 PM
I must say I hadn't heard that one. If so, then using the diesel flywheel would have a marked similar effect, though it would most likely mean using the diesel flywheel housing and starter. That's probably not a route I'd like to go down, though.

I was told that 'Olmate' had the cam changed on his 2a, but I haven't seen him around recently to ask him. I think I'll fire off a PM just in case he's still around.

Otherwise, can I assume it's just a case of trial and error? Any advice would still be greatly appreciated.

Dan.
69 2A 88" pet4 (still in disguise), 68 2B FC pet6 (still resting quietly), plus 14 other parts/project cars (1xS2, 6xS2As, 7xS3s).

dandlandyman
22nd May 2013, 12:01 PM
Just for future reference.....

I met a bloke yesterday who actually had a diesel cam in his 2a. His experience is that it simply improves torque, as in it holds top gear up hills far better. He didn't notice any difference in fuel consumption, running temperature, or driveability. He did mention that it won't rev hard, though I believe he meant that it won't rev harder than normal, rather than having a drop-off in top speed. On that advice, I will be fitting the diesel cam into my 2.25 petrol.

I just thought this info may come in handy later if anybody else is contemplating the same mod.

Dan.
69 2A 88" pet4 (still in disguise), 68 2B FC pet6 (still resting quietly), plus 14 other parts/project cars (1xS2, 6xS2As, 7xS3s)

Blknight.aus
22nd May 2013, 03:53 PM
doesnt really make any more power...

it does fatten up the torque curve at the bottom to mid but robs the torque out of the top end (not that anyone who has any respect for their wallet drives the 2.25 far enough up the rev range to notice it)

IMHO a very cost effective mod if you need to replace the cam and are considering extractors. A better breathing carby will also add to the value. (however most carbies that breath better than the OEM ones will limit you in one way or another off road)