Crossflow spec identification

[Gridgway]

So the spec of my crossflow is a bit of an unknown.  It is registered as a 1600.  The guy I bought from had it a very short time (he changed plans), but the long term owner before that was convinced it was a 1700.  Then there is the question of the compression ratio and head spec (valves etc).

It's a 711m block, doesn't have a Caterham cam cover and I'm just curious about it.  I suspect there's little I can do to check it out without having the head off and there's no reason to do that at 10k miles (assuming compressions and leakdowns don't show any problems).  It seems to pull well although it needs a rolling road setup as it's running very rich and stumbles a lot.

You can definitely still see the honing marks in the bores!

Cheers

Graham

[Neil220]

Please let me know if you find out, I'm intrigued!

[TANGO7]

If the car was supplied as a full kit (including the engine) from Caterham (which, I think, would be shown by a "C" as the 7th letter in the chassis number) then the 8th and 9th letters in the chassis number would show with what engine it was supplied (GS for a 1600 and 17 for a 1700).

If the engine does not have a Caterham rocker cover, I would suspect the car was possibly supplied without the engine. (I think this would be shown as the 7th letter in the chassis number being either an "A", "O" or "S"). Thus the original builder may have sourced the engine elsewhere.

[Roger King]

Yes, I'm afraid it's head off to establish the facts.

Just as a point of interest, it's perfectly possible to have a 1700 engine (1690 actually if it's Supersprint spec) that is registered as a 1600. The Supersprint has a +.090" bore which is a standard oversize for a Crossflow rebore (standard pistons are easily available at this size) so it's perfectly possible to have fitted an exchange engine that is +.090" when the original engine was a standard 1600, even in a Ford Cortina. I don't recall anyone claiming a claiming a capacity increase under such circumstances.

[AnkerB-S]

I believe the easiest way to determine whether you have a Supersprint engine is to remove the valve cover. If it has double valve springs it is most probably a Supersprint. If it has single valve springs it is most probably a 1600, possibly bored out to 1690 cc. The Supersprint also has a different cam, bigger valves and a smoother intake. To get a final answer you have to pull the head, not a big job. It also gives you an opportunity to examine the bores, the amount of carbon deposit, etc.

[Gridgway]

Thanks All,

I'll check the VIN in a mo and report back.  Like my question about the condition of the axle, there's really no need to have the head off if the engine works ok which it does, so I may have to stay my curiosity.

I'll get it on the rollers to get the cabs properly tuned wchih will give at least some idea of what's what.  I'm not ecpecting it to be 1700 supersprint spec though.

And to reassure everyone, I will be out tomorrow giving it a bit more of a blat on its new tyres rather than the originals which are currently on it and give about as much grip as a Red Bull going round to grid up at Spa!  So some driving as well as contemplating and fettling!

[Gridgway]

Quick update, the VIN has GS in there to indicate 1600.