edelbrock carb, rich at wot

JSF55 · Post by **JSF55** » Thu Jun 25, 2009 2:52 pm

Hi guys, hoping the weather will hold for the weekend and get a few passes at the nostalgia nats at avon park, been setting the carb with the LC1 i have and it shows a slight increse to 12:1 on light acceleration and at WOT i'm running at about 11.8 i'm thinking that it needs to come down a hole on the accelerator pump and a smaller jet in the secondries ? engine spec is well used SD1 block, ported and polished heads with wasted standard valves, SD1 exhaust manifolds with downpipes, hurricane cam, rhodes lifters and edelbrock manifold and carb. Any help gratefully recieved, just hoping it goes a bit quicker than last years 15.6

bones · Post by **bones** » Fri Jun 26, 2009 8:29 am

Hi, on mine i had to change the rods to the smallest ones,but i cant remember what the numbers were, mine is a 3.9 rover and others who run a 4.6 changed theres to the smallest ones aswell, someone on here will let you know sizes, as they say, size matters

rich

CastleMGBV8 · Post by **CastleMGBV8** » Fri Jun 26, 2009 9:39 am

What rods and jets have you got in the primaries? my similar spec 3.5 engine ran 1441 Rods and 1421 Jets with stock secondary settings and ran very well.

I never had the a/f ratio checked but a couple of trustworthy people confirmed I had the correct calibration, which for road use was fine.

What size air fliter are you using and what distributor and timing spec do you have.

Kevin.

JSF55 · Post by **JSF55** » Fri Jun 26, 2009 11:16 am

As far as i remeber the carb was set up with 1423(.086) and 1422 (067x055) secondary hasn't been touched 1426 (.095) it was the set up i used on the engine before trying my hand at EFI, it was more seat of the pants than anything else

i've set the dizzy, which is a new item from a 3.9 running pertronix kit , at 36 degrees @ 3000 rpm, too wet to go messing about today, so it's a case of seeing what she runs at the weekend

JSF55 · Post by **JSF55** » Sun Jun 28, 2009 9:35 pm

What a disaster, developed some sort of misfire/ fuel problem, 50 miles after starting and despite, changeing plugs, leads and stripping down half the carb, it still persisted, managed too nurse it all the way home and waiting for some time to investigate ... hoo hum

CastleMGBV8 · Post by **CastleMGBV8** » Mon Jun 29, 2009 9:37 am

Sorry to here about your problems, especially when it's not easily identifiable. i'd hazard a guess at distributor but not familiar with the Petronix system other than it's supposed to be reliable, believe it's the unit Aldon market under their own name. Do you have a spare dizzy you can swap in to check?

Re the jetting, your quoted Rod size (067 x 055) is 1463 with stock jets which is clearly too rich and in fact what I have in my new 4.35 engine and what others are running in road/track 4.6 engines.

When youv'e sorted your problem, if you want to try the original set up I had in my 3.5 I still have the rods and jets which are now surplus to requirement, my 3.5 heads and cam were same spec as yours so should work ok but with the LC1 you can check.

Kevin.

Kevin.

JSF55 · Post by **JSF55** » Mon Jun 29, 2009 5:37 pm

Cheers Kevin, busy sourcing parts to try, i have a spare points dizzy and cap and leads, mate has a spare coil, want to do a compression test first to make sure there's no motor damage keep you all posted

john

JSF55 · Post by **JSF55** » Thu Jul 02, 2009 10:22 pm

Just to conclude this post, i hit it with new plugs, cap and rotor arm, an older set of leads and it started fine and runs perfect, will need to spend a little time checking everything over before venturing back to shakey in september

CastleMGBV8 · Post by **CastleMGBV8** » Fri Jul 03, 2009 8:08 am

Pleased to here you got it running well, did you change one thing at a time to find the culprit or change every thing at once.

I always like to know what was causing a particular problem, but sometimes it can be a combination of parts contributing to the issue.

Kevin.

JSF55 · Post by **JSF55** » Fri Jul 03, 2009 10:58 am

Didn't think it was fuel, checked the engine compression and had about 162-180 on 8 cylinders, so thought plugs, had a new spare cap, so picked up a rotor arm and used some "known to be good" leads on i have some 8mm i'll replace with later this weekend, the halfords trader card saw the bill at £10.20, cheap and easy fix, need to pack some spares for next time tho