QuestionQUESTION: Jim, I am restoring a '74 Spitfire 1500. It has a Delco D204 distributor. When I got it after sitting idle for about 15 years, the wiring {and a lot of other things} had been modified, or just didn't work. Mostly, I have cured the problems, but still have much to do.
Back to the distributor...It came with the spark plug wires oriented with no. 1 to the lower left hole of the distributor, instead of upper left as shown in the repair manuals I have. What does this do to the timing?
Also, I have conflicting data for the ignition points gap. One source lists .010 and the other lists .015. Which should it be?
Thanks, Tom.
ANSWER: Tom,
First off, proper point gap is .015
As to the orientation of the plug wires in the distributor cap, as long as the proper firing order is maintained (1-3-4-2)and the plug wires aren't crossed (leading to crosstalk/misfiring) then the it's not *really* a problem. Then again, it's easy enough to swap them back and if you have outside help it keeps them from being confused if they're used to the Spitfire.
Cheers,
Jim
---------- FOLLOW-UP ----------
QUESTION: Jim, Thanks much. I have one other question. One other "modification" which had been made to the Spitfire was removal of the emissions equipment. All that was left was a vent hose from the rocker directly to atmosphere, with a lot of blowby, and, with the large connection to the carburetor plugged. I connected this hose back to the carb connection which had been plugged. Also connected the vent line from the fuel tank, which had benn left unconnected, to the upper connection on the carb above the fuel inlet.
I was getting blowby from the oil dipstick, but sealed that with plastic tape around the dipstck. I am still getting leakage from the front crankshaft seal.
Would it help to tee off the rocker cover vent line to atmosphere, or to the vacuum connection on top of the inlet manifold? Or is there something else that would help to reduce the crankcase pressure?
Thanks again for your insight.
Tom.
ANSWER: Tom,
From the factory there was a hose from the valve cover and a hose from the carb fitting that went into a "T" fitting with the third leg going to the carbon cannister. The vent from the fuel tank also went to the carbon cannister.
What's happening is some of the exhaust is working it's way past the piston rings and valve stems, building up pressure in the crank case.
The problem with venting from the valve cover straight into the carb is that there's a greater possibility of oil being burped into the line and then being burnt off in the engine. Not only can this lead to more carbon deposits in the cylinders, it can also get you a ticket in some places due to visible emissions.
A compromise is to fit a catch bottle in the line from the valve cover to the t-fitting (or carb, if you keep your present setup). This will catch any liquid oil while allowing the intake to help pull excess pressure out of the engine.
If you keep getting oil past the crankshaft seal then it's a sign that either the seal is shot (semi-easy replacement to do) or that it's time for an engine rebuild. The 1500 is very easy to rebuild and the parts are still available and reasonable, but it's still a chunk of money.
One thing you might try is put a rubber hose around the dipstick tube with a hoseclamp, and put that into your catch bottle / carb fitting also. That'll help pull more blowby from the crank case area.
Cheers,
Jim
---------- FOLLOW-UP ----------
QUESTION: Jim, Thanks again. What would you suggest to make the catch bottle from?
Tom.
AnswerThe catch bottle can be made from just about anything, keeping in mind that it's got to fit into some spot in the engine compartment, seal relatively tightly and be resistant to heat.
I did a simple catch bottle on an autocross car using a Castrol quart bottle strapped to the radiator overflow. On that car I was simply venting the vapors to the atmosphere so getting a second line onto the bottle wasn't a concern.
If you can come up with some bulkhead fittings you can get away with using just about any jar, putting the two fittings into the lid and strapping or clamping the jar out of the in the engine compartment.
Cheers,
Jim
