Zero compression & weber

sandshadow · Post by **sandshadow** » Tue Mar 28, 2006 8:39 pm

I take it you do not have to worry about even lip service to emissions testing?

Not currently. In my state it depends on where you live. Heavily populated regions have emmissions requirements. If worst came to worst, I suppose I could reinstall the old carb before testing. There were very few parts that I would need to replace to do this - the throttle cable is all I can think of offhand.

Since the EGR valve is non-functional without a vacumn connector, I decided to fabricate a block-off instead:

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Post by **ARCHINSTL** » Wed Mar 29, 2006 12:24 am

Again, very nice photos - and workmanship.
A couple of questions:
1. Why are you not using washers under the nuts on the adapter? I've always been a believer in them, to "spread the load," facilitate even torque values and keep the nut from digging into the surface (unevenly). I noticed this on the OE carb on mine, which just went against my grain - so I used SS washers - everywhere.
2. While I have not paid too much attention to Weber writeups, as I have other fish to barbeque (sorry), I wonder why it appears that the PCV valve appears to be attached to a hose that again reenters the cam cover - why is that not redundant? I presume I am missing something here - why not just block it off and avoid drilling another hole?
Thanks,
Tom M.

takza · Post by **takza** » Wed Mar 29, 2006 4:23 am

ARCHINSTL wrote: I wonder why it appears that the PCV valve appears to be attached to a hose that again reenters the cam cover - why is that not redundant? I presume I am missing something here - why not just block it off and avoid drilling another hole?
Thanks,
Tom M.

The PCV draws clean air from inside the filter and passes it thru the crankcase and back into the intake....needs 2 hoses?

sandshadow · Post by **sandshadow** » Wed Mar 29, 2006 7:55 am

ARCHINSTL: 1) No special reason. I was just using the existing nuts and since they didn't have lock washers on the stock EGR I didn't use them on the block-off.
2) There are two breathers on the top of the valve-cover. In a stock setup, the back one runs into the air filter and the front one, with the PCV valve, runs into the pre-heat spacer. (See pg EC-7 in the manual). I removed the pre-heat spacer according to the Weber install guide, so I used a Y fitting to route both the front and rear breathers into the air filter.

I noticed the Weber write-ups with pictures showed the pre-heat spacer still used. This is one of the things I wanted to discuss with the other people who have installed Webers.

GTSSportCoupe · Post by **GTSSportCoupe** » Wed Mar 29, 2006 8:49 am

Crap! I haven't visited this thread in a while. Nice work on your engine!! Very clean and well done! Puts the rest of ours to shame!

Post by **ARCHINSTL** » Wed Mar 29, 2006 3:11 pm

Thanks for the note.
It just looked to me (and frankly, still does), that the PCV hose leads to the OE rear hole in the cam cover, and another hose leads from a new hole to the Weber. I guess the Y-connection is just not visible (to me, anyway).
Mr washer reference was actually to the nuts on the white carb adapter (boy, that manifold looks nice - bead-blasted?).
As before, your engine bay sure looks great.
Tom M.

sandshadow · Post by **sandshadow** » Wed Mar 29, 2006 4:58 pm

Thanks guys,

It still needs a little tweaking. When I drive it warm it revs high (~2000 RPM) when I come to a stop. "bliping" the throttle causes it to drop down to the correct RPM. I think I overtightened the throttle linkage.

ARCHINSTL: I think what you see as leading into a new hole in the valve cover actually is the Y connector. And I just had the guys who did the head job dip the intake manifold (they were nice enough to do it for free).

I washed the engine compartment before starting the work, but it was pretty clean beforehand. It was a pretty nice looking car for $600

(of course, it's up to $1600 with the head job, carb, and miscelaneous other parts)

Gasoline Fumes · Post by **Gasoline Fumes** » Wed Mar 29, 2006 9:42 pm

sandshadow wrote:There are two breathers on the top of the valve-cover. In a stock setup, the back one runs into the air filter and the front one, with the PCV valve, runs into the pre-heat spacer. (See pg EC-7 in the manual). I removed the pre-heat spacer according to the Weber install guide, so I used a Y fitting to route both the front and rear breathers into the air filter.

The PCV valve needs vacuum to function properly. It won't do much of anything hooked up to the air cleaner. The port on the preheater is just intake manifold vacuum.

sandshadow · Post by **sandshadow** » Wed Mar 29, 2006 11:44 pm

So the blow-by gasses are pulled from the crankcase rather than pushed? I didn't realize that. When the PCV hose is disconnected, it does blow some gasses out the valve so there has to be some pressure in the crankcase.

Oh well, there's still got to be lower pressure in the air filter where the carb is scking in. I'd rather do this than either leave the PCV open or capped. I suppose I could put the pre-heat spacer back in...

Gasoline Fumes · Post by **Gasoline Fumes** » Thu Mar 30, 2006 11:56 pm

sandshadow wrote:So the blow-by gasses are pulled from the crankcase rather than pushed?

Yep. I doubt your setup will cause any major problems, maybe just a slight increase in oil consumption. Having vacuum in the crankcase keeps oil from sneaking past the rings into the combustion chamber.