The Tweaking Begins

It's surprising how quickly 600 miles have been racked up in the cobra, just from a few trips around the local villages on the back roads, pootled to work in the frost/ice (that was interesting!) and a few other short journeys when the weather has allowed. 

Following the Christmas drive when it was running quite badly, I bought a vacuum gauge and adjustable timing light. The engine info from BAE said the engine should have 36deg "all in" timing at 3000rpm. It was set purposely retarded for run in. I measured this at approx 24deg all-in, static timing was about 4deg so total centrifugal advance is around 22deg. The engine came with no vac advance fitted, dizzy is a newer style HEI with module built into the cap. 

I went for 20min drive to get everything warmed up then set the timing to the 36deg all-in figure, which would give static timing at about 14deg but I forgot to measure and check this. The car re-started easily when warm but the morning after it kicked back against the starter so I had to back off the timing to 32deg all in and it seems fine now.

Using the vac gauge at idle I was getting 9-10in.hg at idle which is pretty low but my cam is pretty big, comp cams xe284h with following specs:

Advertised Duration		Duration @ 0.050		Valve Lift W/1.5 Rocker		Lobe Sep. Angle	RPM Operating Range
Int.	Exh.	Int.	Exh.	Int.	Exh.
284	296	240	246	.507	.510	110º	2300 - 6500

Knowing that my idle set-up was pretty crap, I set it back to "stock" according to the Edelbrock carb manual. It advises that for a reasonable setup when trying to get a new carb to run, you wind the two mixture screws in until they bottom out, then out 1 1/2 turns, then this is your base setting. I did this and immediately saw better vac and the revs rose. I backed off the idle speed screw to get the revs down to about 850 but its hard to tell exactly what revs as the needle isnt steady. I ended up with the mixture screws out roughly an extra turn which gave peak idle vacuum of almost 13in.hg but again this value wasn't steady but probably due to the cam and varied by ±0.5in.hg.

Went out for another drive and it was a little bit better but still lurches and kicks a bit below 2200rpm so I'm wondering if the idle throttle position is still slightly too large which will uncover transfer slots etc that I'm still learning about and trying to understand.

More fiddling required, next stage is wideband O2 sensor to see if I can home in on a better idle mixture setting.

Christmas Drive

Managed to fit a new oil sensor without breaking anything.  Removed the extra baffles so we are now down to the standard unmodified Dave Brookes exhaust and is not that much louder,  you can still talk to your passenger under 50MPH or so then it's the wind noise that gets you.

My intention was to do 20 miles or so and get it warmed up,  then set the mixture and timing but as the father in law was here for Christmas we just enjoyed the fact that it was running (albeit badly) and had an hour or so out and about, did 60 miles or so in the end without much trouble.  It sounded a lot sweeter now with 20/50 valvoline mineral oil in it, I realised when I got back that we had gone out with no tools for emergencies but thankfully didnt need any! I thought I had fixed the wing mirrors and stopped them from folding in at speed but they are still completely useless.

Oil Change

Now, I've changed oil before on cars. It's not that difficult, however what the last 3 years have taught me is that its pretty easy for a simple job to spiral out of control. Yesterday we had a happy, working vehicle. Today we do not.

The magic 500 miles (or pretty close to 500) was clocked up yesteday so today I thought I would change the oil, as advised by the engine run in procedure from BAE/Custom Power and Paint. The oil oil filter was an absolute arse to remove, had to shove a screwdriver through and made a good old mess. The new one was supplied with the engine, a Fram PH25. Old one was an AC Delco PF454. They are not the same!

Oil filter mount in the engine below - the Fram filter seal position is wrong.

After much headscratching I realised the PH25 is meant to fit the oil cooler takeoff sandwich plate that came with our engine. We haven't fitted the oil cooler yet because it requires some creative bracketry at the front and in this weather its not really needed, so I was planning to leave it off for now. Unfortunately this means that until I get another oil filter I can't use the car. Word on the street is that the Fram filters are pretty crap anyway.

So, I had warmed the garage up and didn't want to waste it, I've been out the garage for a bit during the gap between IVA and registration and I'd forgotten how much I actually enjoy whiling away the hours fiddling around with the car, even if I then complain about things going wrong on here! Next job on the list was to replace the leaking oil temp sender. It's a 1/8NPT thread into a 1/8 - 1/2 NPT adaptor which then goes into the sump. I dug out a copper washer and put the new sender in the adaptor, tightened it up and.....

Whoops! So now I have a car with no oil filter and no oil temp sender, in need of new parts a week before Christmas. Hopefully we can get it sorted so the father-in-law can have a drive on Christmas day.

Now registered

Friday 13th December,  tax disc and v5 plopped through the letterbox so went to Halfords Saturday morning to get some number plates made. Car is new 63 reg as planned. Hurrah! First job ticked off the list - clear indicator lenses on, looks a lot better to my eyes. Haven't got a picture from the front yet, too busy driving it! The radiator mesh has been removed to improve air flow to the rad.

Hairy Canary