Metering Plates, six pack

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CRUZE 418

CRUZE 418

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It seems like I have looked everywhere, but can not find the size of this metering plate for the end carbs # 34R-6153-B.
 
Sorry, I need to rephrase my question. What is this metering plate size in relationship to a jet size. # 34R-6153-B
 
Was not there. I'll get hold of Chicago Carburetor or Holley today.
Thank you anyway.
 
Chicago Carburetor. Zip
Holley. Zip
Chrgdrt. Not sure that I understand your answer. Can not pm you either.

Starting to look like I will just put the Pro Max plates back in. Did not realize that this was going to be such an elusive question.
Thank you all. I'm out.
 
CRUZE 418 said:
Chicago Carburetor. Zip
Holley. Zip
Chrgdrt. Not sure that I understand your answer. Can not pm you either.

Starting to look like I will just put the Pro Max plates back in. Did not realize that this was going to be such an elusive question.
Thank you all. I'm out.
Click to expand...
the size of the main jets on that plate are .086"(hole A left side of pic) on the drives side and .073" (hole a right side of plate)on the passenger side. these are not jet size but but measured in inches I don't have my conversion chart handy, the idle feed restrictions are the upper holes and the measure .037"(holes b).
N2cwFXm.png


curious why are you looking to put the original plate back in?
 
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Was looking at my options, met a drag racer from Minnesota at a mopar drag race this past weekend. Someone named Brad VanLant did his carbs. on his race car. He has used pro max and metering plates. Is currently using metering plates. Can not reach VanLant, supposed to have previously been with Holley.
Long story, bought car last year and had Phil Fish go through my carbs, big mistake.
Anyway, he took the pro max plates out and put the Holley metering plates back in.
I am trying to get a stagger for jetting on my new 418 engine. Right now, thinking that I will put the pro max's back in. It just seems like it could be a shorter road if I had a ballpark starting point. Trying to follow the article " how to tune a six pack ".
Thank you!
 
There is fair amount of confusion with figuring out the equivalents for metering plates.
Wish I had a staightforward answer but I don't.
See this thread.
Secondary metering plate vs Secondary Metering Block?

In that thread you will also find the original picture mark up by GNTKLR (Mike) was corrected in Tuner's post that follows.
upload_2020-8-29_13-12-55.png

In the metering plate, that isn't an 'emulsion' feature, like the air bleed well acts in a primary metering block, it is an acceleration enrichment feature. When the secondary initially opens, the well adjacent to the main flow path that joins the main where you circled in red acts as a source of acceleration enrichment. The fuel standing in that well when the secondary is closed is downstream of the restriction of the main jet and readily enters the flow when the main nozzle starts through orifices larger than the main jet.

A metering block has similar acceleration enrichment when fuel in the air well is pushed into the main well by pressure from the main air bleed, however the restriction of the small .028" E-bleeds slows the movement of fuel from the air well to the main well, compared to the open orifices in the secondary plate.

Some metering plates, such as original on 3-bbl carbs do not have the partition with the orifice (circled in rid) entering the main flow path below float level, just a single large well.
 
Thanks everyone, VanLant got back to me, think that I have a start tune up.
Mattax, Thank you for the additional web sites. Seems to be a lot of contradiction of what works and doesn't. As with all things, like the airplane that I built, several hundred of them built and though they are the same plane, each one flys a little differently. I have a start plan, and I will read plugs and performance, and adj. with info from there.
Thanks again everyone!
 
I am messing with metering plates on a 440 six pack now. I found this site information but according to Harold Demes (google him for his YouTube videos, he's 'the' man) and much of this is slightly incorrect. Rear plate, 34R6153B #35 has a 0.037" idle hole and the jet holes are 0.093" passenger side, 0.086" driver side. Front plate 34R6153B #34 is 0.037" idle hole and both jetting holes are 0.089". Those are hole sizes, you would need to convert to jet sizes if you are going to use billet plates.
The #35 plates are available out there. The #34 plates are not.
 
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I currently have the stock 340 metering plates in, they are #41. First wot check seemed to be good on the drivers side, rich on the pass side. Was going to just leave it that way for now. Looked at the plugs last nite, it seems to be rich all the way around again. Should be lean, it's fall here and cool out. After a summer of playing with them, I think I may know why people have had such a headache with them. I have had the promax plates in also, with main Holley jets, just never seem to get it right. Going to have to buy one or two sets of those hole sizing sets.
Next year, this year is a wrap.
 
CRUZE 418 said:
I currently have the stock 340 metering plates in, they are #41. First wot check seemed to be good on the drivers side, rich on the pass side. Was going to just leave it that way for now. Looked at the plugs last nite, it seems to be rich all the way around again. Should be lean, it's fall here and cool out. After a summer of playing with them, I think I may know why people have had such a headache with them. I have had the promax plates in also, with main Holley jets, just never seem to get it right. Going to have to buy one or two sets of those hole sizing sets.
Next year, this year is a wrap.
Click to expand...
Did you ever get rid of the number 41 plates ? Thanks Steve
 
CRUZE 418 said:
No, I have them.
Click to expand...
Reason I'm asking found out if I took the #41 plates and installed them in the 71 440 end carbs since they don't make or have the 340 70/71 end carbs in stock .. I could then us the 71 440 end carbs since they are still in stock thur Holley .. Thanks Steve
 
So, are you buying new carbs from Holley? I take it that you have a 340, and can not get 340 6-pack carbs and are going substitute 440 carbs? I would still get Promax metering replacement plates and a Promax rear baseplate so that you can adjust the rear carb. Do you have an intake manifold?
 
CRUZE 418 said:
So, are you buying new carbs from Holley? I take it that you have a 340, and can not get 340 6-pack carbs and are going substitute 440 carbs? I would still get Promax metering replacement plates and a Promax rear baseplate so that you can adjust the rear carb. Do you have an intake manifold?
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I have a 340 and purchased a 350 center carb a few years back and should have purchased the end 500 carbs too.. and now I found out the only end carbs are for the 70/71 440 six- packs and yes I have a new six-pack manifold ..
 
Except for numbers, don't believe there's much difference between the carbs. I would still go the Promax route. You can a least reset and adjust idle mixture. All 3 carbs contribute when idling, not just the center carb. You can not adjust the rear carb with the stock baseplate. When they are right, they hit like a freight train. I have tried 440 carbs on my 418, they aren't much different.
 
CRUZE 418 said:
Except for numbers, don't believe there's much difference between the carbs. I would still go the Promax route. You can a least reset and adjust idle mixture. All 3 carbs contribute when idling, not just the center carb. You can not adjust the rear carb with the stock baseplate. When they are right, they hit like a freight train. I have tried 440 carbs on my 418, they aren't much different.
Click to expand...
Thanks for the information on Promax ... if you ever decided to part with the stock #41 plates let me know :) Thanks Steve
 
Phil Fish did my carbs, he put the #41's in. Maybe he has more. He used to advertise in MCG. He got on my bad side when he shipped my carbs back in an unprotected box, they got damaged and he did not insure them. I could have done what the self proclaimed professional did, only without the damage. Al he did was Sixpack carbs. Or maybe Chicago Carburetor? They are on the west coast, and have a Sixpack section.
Greg
Good luck!
 
It's been 2 or 3 years, since I started this thread. I have a little better handle on this. Think the reason that my plugs always look bad is non ethanol gas, but haven't driven the car this year yet because of other updates to car. My other cars plugs are clean with ethanol gas. Thank you Woodys_cuda for the tip. Will keep for the future!
Thank you
 
CRUZE 418 said:
Was looking at my options, met a drag racer from Minnesota at a mopar drag race this past weekend. Someone named Brad VanLant did his carbs. on his race car. He has used pro max and metering plates. Is currently using metering plates. Can not reach VanLant, supposed to have previously been with Holley.
Long story, bought car last year and had Phil Fish go through my carbs, big mistake.
Anyway, he took the pro max plates out and put the Holley metering plates back in.
I am trying to get a stagger for jetting on my new 418 engine. Right now, thinking that I will put the pro max's back in. It just seems like it could be a shorter road if I had a ballpark starting point. Trying to follow the article " how to tune a six pack ".
Thank you!
Click to expand...
The Promax plates are not properly engineered if you look at your carburetor there is a big void right behind the plate the small sheet metal plate that comes with the original equipment metering plates is designed to seal the plate to the thin sheet metal plates so the carburetors do not take on unmetered bypassing the jet all together. These sheet metal plates are not used on the Promax set up.
Study this for yourself and you will see that the gasket goes over the void on the carburetor and the plate goes on top of that so there's nothing keeping fuel I'm going around the Jet and behind the plate. Recently A friend of mine went to West Tech have his engine dynoed and it had these plates on it and they simply would not respond to jetting the discovery was made after the dyno session that these plates do not seal, I've talked to the guy at Promax to give him the heads up, and he said some people fill the void with epoxy which since then we have tried and it now responds to getting change
 
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