knocking / pinking

[Guest]

I had to take the timing cover off my '69 912 and, after replacing it and setting the timing, it seems to be 'knocking' at idle. The manual contradicts itself by saying 5 degrees in one place and 3 in another for advance at idle. Either way it's knocking at 3 or 5. I thought maybe my ears aren't in tune with the high compression ratio engine, but it does sound a bit wrong. It's a 1720cc engine with an 050 distributor. I've changed the points, condensor, rotor arm and cap. Could it be a dwell angle problem, should I be using a lead additive, is the advance different for Shasta pistons, should I try some different plugs (I've got the ones recommeded in the Duane Spencer book)? Any ideas?

Here's a picture of the engine - not much help with my problem, but doesn't it look nice!

http://www.soton.ac.uk/~aijf197/Engine.jpg

Thanks Alex

 

[912UK]

that engine looks like an AJP engine. You been touching his engine you in trouble [&:]

[][]

I would give Andy a call and talk through what you have done with him does sounds like something has not been done right. Is the car in SOuthampton? as I am coming in to town tomorrow morning..

Mark

Oh where did you get the parts from. is G&S in Totton Tim the ex owner is not there any more and he was the ONLY one who knew which caps and rotors were for the 050 trust me on this and they now will give you the wrong stuff. I think you need to back track what you have done. happy to help if you need it. Could do with taking my 12 out for a run.

 

[Guest]

I got the distributor parts from Roger Bray. G&S couldn't help. The condenser bracket needed slight modification, but fits ok - it's the capacitance that's important not the bracket!

It is indeed an Andy Prill engine (does he put dodgy blue anodised bits on all engines or did the last owner request them? - not exactly the 1969 look). One thing that's interesting is that the distributor shaft has been put in at 180 degrees to the position stated in the manuals I have. Although these manuals disagree by 20degrees. Anyway, that angle is largely irrelavent. If you look at the picture that Helen put up of here engine and the one of mine, you can see that the distributors are at different angles. I'm sure it's all put together correctly. Since my post I re-adjusted the dwell angle, which I hadn't got quite right. This didn't stop the sound completely, but a blast with an octane booster, which should have brought the RON up to about 103 seemed to sort things out. I'm going to try a few high octane tanks and then revert to Optimax. I know the car was running too rich when we got it, so a good clean should do it the world of good.

I tuned the carbs before doing anything with the timing. Since the car seems to have been neglected over the past few years, it's likely that the timing was out and I should now re-tune the carbs with the renewed ignition system. This will probably improve things.

Thanks for offering to come over. I didn't get you message until now though. Hope to meet up soon. Perhaps a blast to the New Forest followed by a swift half?

Alex

 

[912UK]

Sounds good as we are only local. Your car's engine was done my Andy the blue Ali contecions are not 69 your right but for the newer oil filter system which will help alot with cooling. Any questions you have with the engine I would put to Andy as he really does know these engines well. I have put the 69 in storage for the winter now unless we get a good clean dry Winteresday then I will take it out. I am still working on getting the 65 up and running soon and then the on going project of the 54.