Distributor curve

[Mikes73]

That's a win in anyones book, glad to hear it is running nice::thumb::

 

[jpaz]

Thank's to all who have helped me on this thread! I have learned a lot from all the great advice, & all the older threads I looked up. A big thank you to barnett468 & jeff73mach1, you both are a great asset to this site, for not only helping me, but everyone else you guys help out too!

I just got back from another drive, running real good. Thank's again to everyone.

So is a 6.5 power valve usually what comes in 4150 style Holley's? I'm not sure what they come with.

It's running so good I was planning on driving it like this for awhile. I haven't taken it on the freeway yet.

most carbs come with a 6.5 and that is the most common power valve used.

holleys power valve suggestion guide used to be pretty much useless because in fact, they used to tell you three completely different ways to determine what the best power valve was and they all contradicted themselves to some degree . i found this out around 10 years ago when someone else mentioned it to me because i had never read any of their info . i have been building and tuning cars since 1970 but learned some on my own and some from others, so i never needed to read it.

i just looked online and saw the link below which is different than what i had seen before and it is far more correct, however, it is only a guide and if you still have probs using their method, you should try something else because tuning is a bit of an art and what works for one app, doesn't always work quite the same for another.

http://forums.holley.com/entry.php?430-Holley-Power-Valve-Tuning

you spent maybe $10.00 for two jets and maybe a total of one hour tuning your engine based on suggestions on your thread and it now roasts the tires from a dead stop and will spin them when it hits second gear and it has absolutely zero hesitation . in my experience, once a car does this and still idles decent etc, there is little, to nothing else that will make it any better, however, it never hurts to try.

I still need to finish, now what do I do about distributor advance? Should I hook it back up?

 

[barnett468]

I still need to finish, now what do I do about distributor advance? Should I hook it back up?

There are a couple different options . Below is what I would do and hopefully it makes sense.

1. With the engine warm, raise the rpm to around 2200 . If you don't have a tach hold the throttle around 1/3rd open and check the timing.

2. With the throttle in the same open position, connect the vacuum can to ported timing.

3. Listen for a difference in rpm and for slightly erratic running.

4. Subtract the big number from the small one and this result will be very close, if not exactly how much timing the vac can adds.

5. If your vacuum can is adjustable, set it to add 5 to 6 degrees of timing . This will probably be with the adjustment screw around 5 turns out from full in . Out reduces timing and in increases it.

Turning the adjustment screw will also change the initial timing also, so recheck the initial timing after changing the screw position.

6. After the vac can has been set, repeat step 1 thru 4 . If the rpm increased and it still runs smooth, I would connect the vac can to ported vac and test drive it . You may not notice a difference in performance but it will increase your mileage slightly.

NOTE

Check for vacuum at the ported vac port at idle . If it has vacuum, you can not use the vac can unless you correct this . If it needs correcting, we can give you a couple suggestions on how t do that.

.

 

[jpaz]

Makes sense & I will try this later today. Thank You!