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Sun Jul 06, 2008 8:29 am

In your very first post, you said:
Quote: Stock 1600 DP with a mild cam.

So...not a stock camshaft? Do you have an idea what the deviations are required to be due to that camshaft? I seem to remember that in general, performance mods that improve the engine's volumetric efficiency tend to require richer jetting. Since the idle jets in the carb are probably stock, then you're having to goose a lot more fuel into it to keep it running right. And the extremely advance timing is probably indicative that it's still running very lean.

So...maybe this is par for the course for that cam?

So your problem with the bypass screw is basically that at idle, the engine can suck as much air as the bypass tube can handle to just come to the right idle speed?

Wed Jul 09, 2008 3:25 pm

Well it's a Engle W 100 cam. I don't have the specs handy. I expected maybe a slightly bumpy idle, but this is no good. I'm assuming that it's not the cam at this point. I see what your saying though....

The bypass screw and mixture screw have little effect. If I start with the typical 2.5 or 3 turns out, and 0 deg or a bit AFDC ignition, it's hard to keep running, even while adjusting the screws.

When I bought this car and before I did anything, this is the way it was set up. Way advanced distributor and mixture screw way out. So now why do I have to set it up that way to keep it running?

The only thing that hasn't been changed out is the carb. It is a new Brazilian carb. I'm reading that these carbs are not so good right out of the box. I took it apart but didn't see anything obvious. Blew out the passages, appear clear.

Geez... This is NOT how I wanted to spend my summers after work!

Fri Jul 11, 2008 6:29 am

gakali wrote: Well it's a Engle W 100 cam. I don't have the specs handy. I expected maybe a slightly bumpy idle, but this is no good. I'm assuming that it's not the cam at this point. I see what your saying though....

Well it might be that most folks that put in a hotter cam also put on more carburation, and so they don't see this problem.

Quote:
The only thing that hasn't been changed out is the carb. It is a new Brazilian carb. I'm reading that these carbs are not so good right out of the box. I took it apart but didn't see anything obvious. Blew out the passages, appear clear.

Something to check: if memory serves, the jet that controls the amount of fuel at idle is the one that screws into the right side of the carb; it has a hexagonal head. You can just remove it with a wrench. Take it out and check the number. I think I read that stock, it should be a 55 or 60. You also might soak it in carb cleaner over-night and then put it back in.

Quote: Geez... This is NOT how I wanted to spend my summers after work!
Then I think you should have bought a Honda or Toyota. :-D

Sat Jul 12, 2008 9:09 am

OK I deserved that last one...........

It's just frustrating at times.

I'll look into jetting.

Thanks everone for your help.

Sat Jul 12, 2008 9:35 am

i would make sure where TDC is, and not trust the pulley, it might be off a little.

do the ol' wooden spoon in the spark plug hole trick....carefully...

Sat Jul 12, 2008 11:57 am

Crippler wrote: i would make sure where TDC is, and not trust the pulley, it might be off a little.

do the ol' wooden spoon in the spark plug hole trick....carefully...

I just picked up a degree wheel and dial indicator.

I'm going to verify TDC and check the cam timing. I have a new Engle W100 cam. Surely the stock idle jetting would let it idle. I may have to rejet it for top end, but I want to get it idling decent first.

I did a leak down test and it was about 10% on all 4. That makes me feel good!

Sat Jul 12, 2008 9:55 pm

gakali wrote: I'm going to verify TDC and check the cam timing. I have a new Engle W100 cam. Surely the stock idle jetting would let it idle. I may have to rejet it for top end, but I want to get it idling decent first.

Sure it will--with all the adjustments at the extremes, as you have found.

If you haven't checked something, then you can't assume that it's right. I see no reason to believe that your idle jet is correct until you take it out and check the number. There's probably a range...and if it was set at the lean end of the proper range for a stock 1600, then yours is going to run too lean which is what you're finding.

Quote: I did a leak down test and it was about 10% on all 4. That makes me feel good!

Excellent. Now you know that it most likely isn't that. :-D

Sun Jul 13, 2008 10:42 am

The saga continues....

The cam timing looks OK. My numbers were a bit differant then the cam card. I attribute it to being checked at the rocker, and not the lifter. Certainly close enough to allow it to idle anyway.

My idle jet is the stock 55.