[kwilford]

George,

VERY nice! I have been considering the same carb adaptor for my Weber in place of the "normal" pancake filter on top (albeit with a K&N element), but I wondered if the throat would fit the stock air cleaner bellows. Did you happen to try that before you fabricated the pipe?

 

[Bosco2]

so have you verified that its able to breathe well enough.....that it's not too restricted at the oval opening closest to the carb?

 

[opelenvy]

I wondered if the throat would fit the stock air cleaner bellows. Did you happen to try that before you fabricated the pipe?

Yes, I did try it out, the stock bellow is quite a bit bigger, maybe 3.5" or more.

And I have no way of verifying how well it breaths aside from running it.
Can anyone tell me if this is messed up logic. I have a 2" exhaust pipe going out the back, so the 2"x2.5" oval on the adapter is still larger than the exhaust. I know there are other factors, but I figured it can only take in as much air as it can put out at the same time. So the 2x2.5" oval being the most restrictive part of the intake will be no problem.
The walls of the opening are pretty thick as well and I plan on using my handy dandy die grinder and opening it up as much as I safely can. Every little big will help. (I don't know what you are talking about. Is that a Freudian slip?)

 

[tekenaar]

Yes, I did try it out, the stock bellow is quite a bit bigger, maybe 3.5" or more.

. . . and I plan on using my handy dandy die grinder and opening it up as much as I safely can. Every little big will help.

ROFLMAO!

 

[BQS4]

The "Otto-spell-check" strikes again!

 

[madhatterpdc]

Opelenvy,

You may want to consider that the exhaust system operates best at a small diameter in order to maintain exhaust gas velocity. Remember that it has a very long distance to travel before escaping out the tail pipe and before the next exhaust gas charge comes barreling down the headers after it. That being said, Your intake configuration should be sufficient, using the same principles of velocity vs. volume. Consider the stock "snorkel" ID is considerably smaller. Granted your engine is probably breathing a lot deeper than a stock mill, but you also have to figure that you have a K&N in a "cold-air intake" position... cold air is a lot more dense and will flow better through your ovoid constriction.

Don't take my word as gospel, this is what I call "napkin engineering" (rough formulas, no measuring, and a few vague assumptions)

 

[opelenvy]

Bad news on the cold air intake.

Well the good news is I figured out what was causing the stumble when I kicked in the secondary, the bad news is it is my cold air intake setup.
I had tuned my carb. and had it running good with nothing on it. When I put on the intake assembally, I got the stumble with the secondary. So I removed the jam adapter, the stumble is gone. I put only the Jam adapter on without the pipe and filter and I still get the stumble. It does fine on the primary, but with the extra gas of the secondary it seems it's not getting enough air. Another guy had made a riser to make the adapter level with the top of the carb. and that might fix the problem. Or the problem may be the opening of the snorkel. I will do some testing and try to find out. I don't get a lot of time to work on my car right now, so it will take a while. The other snorkel kit listed in this thread may be a better candidate. I think it comes from Weber or JTOutfitters.com or something. I know a couple guys have used it. Oh well....back to the drawing boards. I'll post my results, though it will be a while. So don't go using my design just yet. I am going to try and contact Jam Engineering and see what they say. Stay 'tuned'....

 

[Chuck Luther]

Opelenvy,
I was the one who made the adapter for the Jam Adapter. I haven't been able to test it yet because I have been doing Pertronix upgrades and, like you, don't have time for the car. I was thinking if it works well I can have a few adapters made to get them out to those of us with the Jam Adapter. I have the prototype! I could even send you my part, if you promise to send it back, to test!??
Chuck

 

[MICAH1]

Adapter Test

Chuck, I copied opelenvy's cold air intake and would be interested in the out come of that test with the additional stack on the weber.

 

[Chuck Luther]

pict

Micah1,
I would let you try it, but lets let opelenvy reply first... if he doesn't want to test it I can let you borrow it! Then we can see about having some made if it works. It cost me 120 to get the old adapter, used with the original snorkel, milled down by a machine shop. Quite pricey but I thought it was necessary.

This shows a pict of it...
http://www.opelgt.com/forums/showthread.php?t=3419

and yes it does fit under the hood!!

 

[tekenaar]

Air and all these jets . . .

Well the good news is I figured out what was causing the stumble when I kicked in the secondary, the bad news is it is my cold air intake setup.
I had tuned my carb. and had it running good with nothing on it. When I put on the intake assembally, I got the stumble with the secondary. So I removed the jam adapter, the stumble is gone. I put only the Jam adapter on without the pipe and filter and I still get the stumble. It does fine on the primary, but with the extra gas of the secondary it seems it's not getting enough air. Another guy had made a riser to make the adapter level with the top of the carb. and that might fix the problem. Or the problem may be the opening of the snorkel. I will do some testing and try to find out. I don't get a lot of time to work on my car right now, so it will take a while. The other snorkel kit listed in this thread may be a better candidate. I think it comes from Weber or JTOutfitters.com or something. I know a couple guys have used it. Oh well....back to the drawing boards. I'll post my results, though it will be a while. So don't go using my design just yet. I am going to try and contact Jam Engineering and see what they say. Stay 'tuned'....

Sorry to hear that snorkel was the culprit though I'm glad you found the cause and were not too proud to share it here. Had wondered more than once why others that used the same jets had good results and you still had that stumble. Like you said though, tuning takes time AND perseverance!

 

[opelenvy]

Yea, it was a real bummer after it looked so pretty.
I came up with a way that accomplishes the same as Chuck's, but, sorry Chuck, it was a lot easier. I went to a well drilling place and he found me a piece of PVC tha is the same diameter as the Jam housing (almost). I cut off a slice that is 3/4" thick and dremeled it a bit to fit. I got two longer bolts to raise up the bracket on the inside that the top screws to. The screws and nuts were $1.15, and the PVC was free.
I haven't had a chance to test it yet but the trip to North Texas tomorrow will be the test. If it fixes the problem I would like to replace the PVC with an aluminum spacer. Should be pretty cheap as it is just a 5 1/2" ID pipe. The results looking through the intake hole look just like Chucks, straight shot to the throat. Here is one picture I snapped real quick of the completed project. If it works tomorrow like I hope then I will show more details. I don't want to brag too much if it doesn't work.
The next thing I want to do to it is with a die grinder open up the intake of the Jam snorkel some. The material is very thick and can safely be opened up some.
Oh, and thanks for the offer, Chuck.
Oh, and yes, the hood closes. The close part is the back of the Jam adapter close to the fire wall. The sheet metal behind the hump in the hood is close. But it clears fine.

 

[Scott McDonald]

Hey Opelenvy-

Did I see your yellow GT cruising down to Galveston a few weeks ago? I noticed there was a nice one going that way a few weekends back.

 

[opelenvy]

Hey Opelenvy-

Did I see your yellow GT cruising down to Galveston a few weeks ago? I noticed there was a nice one going that way a few weekends back.

Nope, not me.

 

[N61WP]

George, you can save some more clearance by using a bevled bolt instead of the stud and nut that you show in the picture. Mine has an allen head and fits flush.

Thanks to all for bringing this issue back up. I was worried about this early on when I built mine. I think I might remove it and put the old Weber air filter ass'y on for a test drive.

Jc

 

[opelenvy]

Ya, I've seen that in the pictures. That is not the place to worry about clearance, really, it is in the back of the adapter where it will hit first. My stud is adjustable and I can lower it flush with the nylon lock nut. But the flush look IS much prettier.
And the meet is Saturday, not tomorrow. I thought tomorrow was Saturday all day.
So I have an extra day! I may get to test it before I leave.

 

[GTJIM (R.I.P.)]

The "J Edgar Opel" article, in the Tech files, about warming up a 1970 GT mentions that the stock snorkel set-up gave 2 HP better than the other things tried. Guess Stutgart Universty got to play with the air flow through that too - as well as the aerodynamics of the body!

 

[tekenaar]

Stock snorkel and weber adapter mods on 32/36

The "J Edgar Opel" article, in the Tech files, about warming up a 1970 GT mentions that the stock snorkel set-up gave 2 HP better than the other things tried. Guess Stutgart Universty got to play with the air flow trough that too - as well as the aerodynamics of the body!

Guess my approach wasn't too far off the mark after all! Look at the "K&N Filter for 32/36" thread for the stock snorkel adapter mods I made. Ted in San Antonio is running my carb (his now) with this cold air setup using stock parts and K&N filter. Hasn't had any problems with it even running A/C. I digress.

 

[opelenvy]

Jam's input on it.

I contacted Jim at Jam Engineering. I explained the problem to him and the fix I had come up with and he said he could make a spacer out of aluminum. I tried to get this as a complimentary fix since the kit does cost $60, but no go. He is makeing me one for $25, which isn't bad. I told him after I got it and tried it out that I would let you all know how I liked it and he might get some more orders for it. I should be getting it in a few days and not sure when I can test it out.
Stay "tuned".....

 

[MICAH1]

Great news OPELENVY, I have been searching around for a cheap fix but if their company part does the job I am in. Thanks a bunch for following thru.

BTW, will the new part be of the same type material and style as the original adapter???