Hey guys. I was having a little problem. I have one of those 1460 holleys that have a secondary plate instead of block. And eversince i put in this cam after 4000-4500 rpms it sputters (like its running out of fuel) sometimes it just feel like the engine isnt in harmony(barely on the edge of extreme lean) sometimes you know for a fact it running lean. I though it was the bloddy floats but ive set them before and they are fine/even rechecked.

I was wondering about something that JESTER said. that by putting a bigger carb it will in essence run leaner. Could it be my plate on the secondaries are to lean for my combo. ??? I disregarded that at first but jesters post made me think that the carb maybe thinks im actually asking it for less that all hell when i floor it. It would do it before without the cam but at 5500rpms. I even thought about fuel presure but my fuel system is a little redundant. If i unplug it i can fill a pool in about 5 minutes. :-)

I havent really been able to enjoy my cam because of this. It pull like a raped monkey from idle all the way to 4000. Ive tunned this carb well. It has great throttle response does not bog when floored, and it spends about the same as my old 600cfm carb. its just that *** soon as it starts hitting about 4500 it sputters like a madman. Do you guys think a metering block will fix this.

Any help/comments would be appreciated..

Thanks You guys, you are always a great help..Sorry about lenght

 

Ive never used this basterized secondary plate. Not being able to adjust and find out makes me MAD.

But i dont want to spend it on the metering block right this second if that "might" not be the problem

Also does anyone know what the metering PLATE that i have on now equals to in jet size.

Thanks again

 

My first guess would be running out of fuel from an insufficient pump or a blockage in the line. Obviously you have enough pump..but something might be restricting it. The first thing I would do is run a fuel pressure gauge to where you can see it and watch it when it starts to sputter...see if presure drops.

 

Oh yeah. Metering plates do have a certain jet size equivilent. You can look up the number stamped on the plate. Any good Holley book will have a table to translate...Holleys website might too.

 

Yes the restriction thing is something i was thinking about too. I took the filter out and blew air through it (by mouth, ive been messing with cars to long) and it seemed new. im goint to do the pressure while running test to see. Hope the fuel doesnt splater on my windshield.

This makes me think. Unless maybe the fuel pump being in the front starves out since its pulling. But then again i have a pusher out back. Maybe air getting cought in the line due to my setup. What do you think jester?

im thinking of eliminating the filter out back and in its place running a rubber piece of fuel line, and putting the filter by the carb. Im running 7 psi at the carb right now, at idle which i guess means nothing. controlled by a mallory three port reg.

the website says 124-72 primaries (now 68) and 134-21 secondaries. What the hell is a 21 on the secondaries. Hopefully that doesnt translate as the same as the primaries/secondaries on a standard holley. if it does then thats small.

Anyways thanks Jester for your input ill try this test out tomorow, and let you know. Its good talking to someone that knows their stuff.

Thanks again!

 

Ive looked everywhere there is no translation i can find for the plate numbers!!!

 

the #21 plate is equal to a #76 jet. usually a healthy
motor wants more like an #80jet in the back.
When you accelerate, gravity forces the gas to the back of the bowl and can uncover the "jet" on the bottom of the sec metering plate. One solution is to convert to a metering block and run jet extentions or you could modify your metering plate to accept jets
with jet extentions too. Just drill and tap into the "main jet"
passage from the front of the plate so the jet is now horizontal
and on the lower part of the face of the plate. Be sure the jet extentions don't hinder the float movement. The right TAP for main jets is available from Holley pn#26-1. I don't know the tap-drill size.
Here are the equvilent jet #'s for the different #'d metering plates.

Plate # 8 = jet # 64
9 64
21 75
37 69
39 69
34R5113-3 65
34R9716-3 56
"" "" -12 73
"" " -22 65
"" " -27 79
" " -32 59
" " -34 79
" " -45 79
" " -54 75








You should also check over your fuel lines to see if they are to close to something hot and picking up unnessessary heat.
This can cause a serious bog down the track (vapour lock)
A piece of wood makes a great, cheap heat barrier between the fuel line and what ever is heating it.
check that there is enough gap between your carb bowl vents
and the aircleaner lid. You can trim them at an angle too.
Remove the in-tank pump and move the Holley Blue pump to the back of the car. the in-tank pump may be creating an unessessary lower pressure drop in the fuel line between the blue pump and the tank causing a vapour lock where ever the fuel is being heated along the line.

 

DAMN FBIRD 88 :hail: ... Great information. HEHE I know my fuel line is running right on top of my top radiator hose. Its just sitting on there. could probably couse the fuel to heat up. Anyways will try your suggestions. Ill let you guys know today...

Thank you! It means alot

 

I found out what the problem was. Its to embarasing to post. Damn it pulls nice.....The problem was.......


A CRACKED vacuum line...

 

Oh yeah by the way.... Thanks guys for all the help!!

 

boy-o-boy... somtimes the simplest things make you want to shoot yourself. I seem to recall an older post labelled "the importance of finding vacuum leaks" You should look it up.
I bet that things moves along now, huh. Good work.