View single post by Mark Rosenbaum
 Posted: 10-13-2005 07:43 pm
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Mark Rosenbaum



Joined: 03-12-2005
Location: Kingman, Arizona USA
Posts: 532
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Dan,
A bit lumpy is normal -- the stock cams aren't all that high lift but the duration is 272° seat to seat, which by most standards is fairly radical.  But the engine should smooth out fairly quickly.  The advertisements used to say that a 907 engine would pull smoothly from 2000 rpm up, and in my car's case at least, that's true. 

It's my understanding that a JH in decent tune normally delivers between 20 and 28 miles per US gallon, depending primarily on how it's driven.  I've never bothered to check what my car gets, but on a particular 20-mile mixed city/highway trip that I make occasionally, it seems to consume a bit less than a US gallon.

I'm quite surprised to hear that you had problems with a static timing of 12°BTDC.  Is there anything out of the ordinary about your engine?  You might wish to verify that you have the correct later style crankshaft pulley and front cover, as using the wrong mix of parts apparently gives a 10° error between indicated and actual top dead center and therefore in ignition timing.  A couple of owners have had this problem over the years.  Fig. RM3 in the shop manual shows the two pulley versions, but the Front Cover line drawings in the parts book give a much better idea of what the front covers actually look like.

It's my understanding that your car should have a type 23D4 distributor with Lucas part number 41488.  There are a lot of distributors that will fit, but that's the only one with the correct centrifugal advance curve.  Again, this is something to check when an engine shows unusual behaviour. 

What sort of emissions tests are they doing in the UK nowadays?  Do they provide the owner with actual test data, or just a 'pass-fail' assessment?  With good test data one can often tell a lot about an engine's condition and state of tune.

If you do get a chance to put the car on a 'rolling road' I'd be very interested in hearing about the test, and the results.

Last edited on 10-13-2005 07:47 pm by Mark Rosenbaum