71stingray454

Hi all!

This is kind of a newbie question but here it goes... what does the spacer under the carb do (besides raise the carb)? The reason why I'm asking is because even with an L-88 hood (which is sagging a bit), I'm stuck using a 2-inch filter element on 1-inch drop-base! So my Holley 850 double pumper is not getting enough air. My spacer is just over 3/4 of an inch tall and was wondering if I can replace it with a shorter one (say 1/4") or something. Will it affect performance?
What I don't understand is that I used to have a 3" element and about 1" clearance from the top of the filter to the hood before the car was frame-off restored. My mechanic said the engine was sitting lower before the restoration because it wasn't attached to the frame properly....now it seems the engine is at least 2-3" higher.

I have an Edelbrock Performer intake which is quite high but since it has already been ported/polished, I might lose too much hp by replacing it. If anyone has a suggestion for a lower (but just as good) intake, let me know!

One more thing, my car bogs and approx. 1500rpm, it diesels when shutting off, it stalled a couple of times under heavy braking and has low vacuum on idle (the lights come up slowly)....these are all carb related problems but my mechanic says once I get more air into the car, everything should be fine. I'm no expert but I don't believe that lack of air could cause all this...could it?

Engine specs: 454ci, 11.2:1 compression, comp cam 294, 850cfm Holley double pumper, Performer intake.

Anyway thanks in advance for your help!

Mike

A C

It sounds to me like your motor is sitting too high now, you maybe had it right the first time. That is a lot of difference in the height. I guess I don't understand how the motor couldn't have been attached right the first time, unless the mounts were broken or something. I don't have a big block, but I have seen plenty of setups on the forum that clear an L-88 hood. I think you should run it with no carb spacer at all and see how it runs.

AC

inqbus383

Carb spacers are supposed to give you a couple more of horsepower higher up, but trade some low end torque away. Especially with the high rise intake, you don't need a carb spacer. The minimal gains you may be getting from it certanly are being counteracted by the lower flowing air cleaner. Take it off and give it a run.

Alwyn678

.....Just get rid of the spacer all together

Fevre

If you want to keep the upper end horse, use one of the extreme lids from k & n, supposed to give 500 extra cfm's. Me, I would ditch the spacer since low end torque is good for launching and burn outs. :yesnod:

71stingray454

Hi,

Guys that's exactly what I wanted to hear :) . I'll definitely remove the spacer and let you know how it goes (hopefully for the weekend). Thanks a bunch for the information (you made my day hehe)

Mike

Tominator

I would also recommend going with a drop base air cleaner, it will give you an inch or two more clearance.

I orginally had a 10x2 air cleaner and it restricted my air flow (although I don't have near the motor as you). Once I switched to a 14x3 drop base it made a big diffence in my motor. Then I added a K&N filter to it and it made an improvement too finally felt like the engine was breathing better.

Also two weekends ago I removed the spacer (mine had a 1/4") and it helped with the bog. I think it was causing a vacuum leak.

ylose

I might put a spacer on mine....but its going to have hoses coming off it...pretty blue solenoids and such....they call it juice....doesn't look orange to me...but I have seen orange bottles of the stuff and blue... :jester

some spacers are used to keep the heat away from carb as raising it off the engine .....right? but if it means you have less air cleaner which in turn means less air coming in then it also fails in what it is tryng to counter.....

Alwyn678

some spacers are used to keep the heat away from carb as raising it off the engine .....right? but if it means you have less air cleaner which in turn means less air coming in then it also fails in what it is tryng to counter.....[/QUOTE]

Yes they are plastic(Phenolic) or Wood..keeps gas from boiling in carb

thejaf

Sorry, but I have to step up and say here's your biggest problem: 11.2:1 compression

I had high (11.7) comp in my 406 when I bought it. All the same problems you are having. More than likely you are overcoming detonation by backing off your timing. From there, your car will not idle. Then the idle speed screw is bumped up to overcome too far retarded initial timing. Then because the idle plate is open too far, you car diesels when you shut it down.

now, you low vacuum at idle because of timing and idle plate opened doesn't help any, but it's also because the cam is pretty big. Also, the large square bore carb doesn't help any. I got rid of my 750 Holley DP, went to a Q-Jet, lowered comp by larger CC heads, bumped timing up. Now the car is pretty darned fun to drive, GOBBBBS more low end grunt, and I can run on any high octane pump gas without detonation or adding any snake oil to the gas. And my vacuum is a lot stronger, even with the long duration solid lifter cam in the engine.