Hiya, I got a fox with a built 351w. Fun Budget build. 30 over with Forged flat top pistons, h beam rods, Weiand stealth intake, msd everything ignition, Holley 650 dp, comp cams xe268h cam... etc. the car will not stop running rich, I can cut the timing down below 10° btdc and it’ll not smoke as bad but I feel like that timing is too low. Car runs good jus smokes a little. 200 miles on motor
Engine Tuning issue
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Give it more run time to seat the rings?
is it a lot of black smoke? You may need to tune that carb up. You know carbs very well?
is it a lot of black smoke? You may need to tune that carb up. You know carbs very well?
The rings are moly rings. I heard it don’t take long for them to seat. It’s not a lot of black smoke. It’s just whenever you rev it a decent amount comes out the back. More than I’d like. I can get around a carb good but fine tuning gets me
There are a few carb tuning articles from car craft and hot rod, maybe holley has some too. Keep in mind that a carb is not the only part of 'tuning', also a vacuum secondary carb is a little more forgiving that a double pumper.
i should ask stick or automatic?
i should ask stick or automatic?
I haven’t had the issue before with this carb and I’ve had it for a bit. It might be rings needing to seat. The smoke might be more gray. Any idea of what my initial timing should be at? It’s a stick t5 I’m waiting to break
Here is one by Jeff Smith from hot rod magazine:
www.hotrod.com
Another: https://pitstopusa.com/p-4154-how-to-tune-holley-carburetors.html
I can do pretty good if the carb is on an engine I can lay my hands on, typing something out is something else.
Just make sure the ignition system is working correctly and have a couple sets of plugs handy.
Tuning Your Holley Carb Made Easy
With the continued development and popularity of the Holley four-barrel carburetor, knowing how to properly tune one is very important.
I can do pretty good if the carb is on an engine I can lay my hands on, typing something out is something else.
Just make sure the ignition system is working correctly and have a couple sets of plugs handy.
I would not be afraid to bump it to 12* or even 14*. I used a vacuum gauge to match timing to the highest vacuum reading, you will have to do some readjustment to the carb.
double pumper carbs work very well with stick cars but I found that a vacuum secondary carb works very well on the street and I prefer them.
double pumper carbs work very well with stick cars but I found that a vacuum secondary carb works very well on the street and I prefer them.
Any idea if it might be the rings not sealed yet also? Like a mix of running rich and rings?
pull a plug and post a picture of it for me..
where do I plug my laptop into a carb???
where do I plug my laptop into a carb???
too much fuel, the porcelain will tell you what its doing at idle.. you want a light tan color with a slightly colored outer ring..
you likely need to back some out of the carb, what size jets you runnin?
you likely need to back some out of the carb, what size jets you runnin?
I can’t remember the jet sizes. I think it was something stupid. Probably the problem but I don’t see how it did fine before with jus heads and a cam and now it’s got a full bottom end and it’s starting to act up lol. But I’m still hung up on them rings
Start out by setting your timing to the highest vacuum reading, check your air/fuel and idle adjustment screws with new plugs and drive it for another 3-4 hundred miles at various rpms (nothing high like no higher than 4800-5000) and not a lot of idle time.
you don't want a lot of black smoke, just a wisp maybe.
carb tuning is almost a lost art. A lot of variables,
a vacuum gauge will be your best friend.
you don't want a lot of black smoke, just a wisp maybe.
carb tuning is almost a lost art. A lot of variables,
a vacuum gauge will be your best friend.
So I feel kind of dumb haha but I changed my oil today. Got the break in oil out. And put regular oil back in. And set my timing to 14°. Plugged up my vacuum gauge and it was the highest there. Messed with the carb some and took it down the road. It missed a bit but cleared right up and now it’s not smoking at all. I used semisynthetic assembly lube. I guess that mixed with break in oil didn’t let the rings seal. Carb idles a like 1300 when I come to a stop and push in the clutch. The after like 5-10 seconds it’ll drop down to idle. So I’m pretty happy
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