Carb Cheater

[Spike Strip]

Do you honestly get different vacuum readings from the gas filter (assuming it's clean/new) and the AC or brake line fittings? They shouldn't be different.

You answered it: Most run the original Gas Filter - It just has a thick wire mesh in it and every old one I've taken off is occluded by 35 years of s***. I've never tried to clean one as they're inexpensive. The vac probably pulls down to full after a bit, but again, that component is cheap and available.

I wish someone made a 1/8 BSPT Vacuum tree to replace the finned-cooler for the brake booster/idle up vac source. Be nice to have something with 4 or 5 ports as well as a 10mm (?) one for the break booster vacuum.

 

[CruiserTrash]

You answered it: Most run the original Gas Filter - It just has a thick wire mesh in it and every old one I've taken off is occluded by 35 years of s***. I've never tried to clean one as they're inexpensive. The vac probably pulls down to full after a bit, but again, that component is cheap and available.

I wish someone made a 1/8 BSPT Vacuum tree to replace the finned-cooler for the brake booster/idle up vac source. Be nice to have something with 4 or 5 ports as well as a 10mm (?) one for the break booster vacuum.

Home depot probably has you covered.

 

[LAMBCRUSHER]

McMaster Carr

 

[Spike Strip]

Yes, I've checked McMaster and they have a 1/8 BSPT Barb, so I guess I could just plumb it to a small vac manifold, but I was looking for a Vacuum tree that that's a machined single unit with some threaded in fittings, like they have for plenty of muscle cars, etc. Nothing. I thought there'd be something for vintage Japanese rice rockets or British sportscars, but again, nada.

 

[bcolvin]

Do you honestly get different vacuum readings from the gas filter (assuming it's clean/new) and the AC or brake line fittings? They shouldn't be different.

Sure do. I’ll take a pic when I get a chance . My manifold tree is brand new as well

 

[bcolvin]

Top is from that port of the carb insulator and the bottom is from the manifold tree.

 

[CruiserTrash]

View attachment 4131184View attachment 4131185Top is from that port of the carb insulator and the bottom is from the manifold tree.

I know I’ve done this in the past - measured vacuum in different spots on the manifold - with no differences. But now I’m second guessing myself. If I have enough hose length I’ll move the tee that feeds my vac gauge this morning.

 

[LAMBCRUSHER]

Yes, I've checked McMaster and they have a 1/8 BSPT Barb, so I guess I could just plumb it to a small vac manifold, but I was looking for a Vacuum tree that that's a machined single unit with some threaded in fittings, like they have for plenty of muscle cars, etc. Nothing. I thought there'd be something for vintage Japanese rice rockets or British sportscars, but again, nada.

3D print

 

[LAMBCRUSHER]

I'll also have to check different sinks. My manifold gas filter is where I tie in my vac gauge, and its always been horribly low at idle since the cam and engine work. Maybe I'm getting an eroneous result. Thanks for pointing that out!

 

[CruiserTrash]

3D print

Engine vibrations would likely kill that in a matter of a few months. My experience anyway.

I too, have a fairly low idle vacuum after my engine rebuild which included a reworked Delta cam. Here at 5300' of elevation my idle vac is 12inHg. I actually tweaked the valve lash so there was slightly less overlap - idle vac was about 10.5-11 before.

 

[Spike Strip]

Stock profile Melling camshaft in mine.

 

[edbods]

Late reply, but I've had it on my car for at least three months. Great tuning tool, makes tuning piss easy. As per what Luke says, the auto-tune function (the intake air control valve function) is meant to be used after you've tuned your carb well. You could theoretically just tune the carb on the hottest expected days of the year, then let the auto tune take care of the rest but I honestly don't know how much of a deviation that will be from the coldest expected days of the year. Tuning it like this may or may not also take care of altitude changes on the fly too. I haven't tried this yet as I still have to sort out other problems with the car, but in the meantime, it's made adjusting the idle laughably easy, and the data logger is also really cool and useful.
Most difficult part of the install is probably installing the O2 sensor bung. Everything else can be reversed.
Insanely great value for what you're getting.