[ggevaert]

Hello,

Took carb off (holley streetfire pn 8362) to ensure the transfer slot was ok and adjusted the primary transfer slot to be 0.020. (was at 0.040)

then I noticed that the secondary was totally closed. (i.e. no transfer showing at all)

In a vacuum secondary do you need to have the transfer slot showing at all?

Thanks
Gary

[Richiehd]

Originally Posted by ggevaert

Hello,

Took carb off (holley streetfire pn 8362) to ensure the transfer slot was ok and adjusted the primary transfer slot to be 0.020. (was at 0.040)

then I noticed that the secondary was totally closed. (i.e. no transfer showing at all)

In a vacuum secondary do you need to have the transfer slot showing at all?

Thanks
Gary

Yes, crack that open a hair .020 make you final idle speed adjustment with the primary side

[cdminter59]

That MSD Streetfire Distributor has got your head messed up. But anyway you are adjusting the transfer slots right. They both should be adjusted about .020. Get rid of the Streetfire distributor and get the MSD-8360. It has the bushings you change to adjust the mechanical advance. I think the vacuum advance is the same setup as your Streetfire.

[ggevaert]

Cdminter59, you are absolutely correct and, at this point, I am seriously considering getting the big boy. Although I am looking at the 8365.

However, having said that, I am a dog with a bone now and I am really interesting in figuring out why my mechanical stop is not working so I'm going to play with it a while more before going ahead. if it works for everyone else then I should be able to get it working !

Thanks for info folks; I'll adjust the secondaries.

[cdminter59]

Originally Posted by ggevaert

Cdminter59, you are absolutely correct and, at this point, I am seriously considering getting the big boy. Although I am looking at the 8365.

However, having said that, I am a dog with a bone now and I am really interesting in figuring out why my mechanical stop is not working so I'm going to play with it a while more before going ahead. if it works for everyone else then I should be able to get it working !

Thanks for info folks; I'll adjust the secondaries.

ggevaert, Have you called a MSD tech about this problem. Has your warranty ran out on this distributor? I don't know if they will have a problem with you trying to adjust the mechanical advance. As the others 8360 & 8365 state that have an adjustable mechanical advance.

[cobalt327]

Originally Posted by ggevaert

Hello,

Took carb off (holley streetfire pn 8362) to ensure the transfer slot was ok and adjusted the primary transfer slot to be 0.020. (was at 0.040)

then I noticed that the secondary was totally closed. (i.e. no transfer showing at all)

In a vacuum secondary do you need to have the transfer slot showing at all?

Thanks
Gary

0.020"-0.040" is the baseline setting (about square, or open as far as the slot is wide). It is not at all unusual or incorrect to have the primary transfer slot at 0.040"- in fact that's more common than less if there's any kind of performance cam involved. The baseline for the secondaries is almost closed, then open as needed to get "bypass" air.

The initial timing has a lot to do w/this as well- if there's not enough initial timing, the transfer slot will almost always end up overexposed, and the idle quality and off idle response will suffer as a result.

The goal on setting the initial timing as it relates to the carb's transfer slot is to find the correct amount that will allow a clean idle without the carb primary butterflies needing to be opened so far at idle that the transition slot becomes over-exposed. This condition will cause a stinky "rich smelling" exhaust (it actually is unburned hydrocarbons, not necessarily too rich). It will also cause a poor quality idle, nozzle drip and poor transition off-idle.

Good luck.

[ggevaert]

CDminter59, I did call MSD and they basically said that I am modifying a distributor in a manner that is not recommended for that particular unit so they can help me. They recommended I go to the adjustable one. Lol, was what I expected.

Cobalt327, that is the procedure I followed and listed next.

Ok, progress on the Holley.
* idle timing continues to be at 18 with a medium spring in the distributor that kicks in at 1200.
* got the primary and secondary transfer slots set at 0.020 and reversed the secondary transfer slot screw so I can adjust it on the fly.
* Started up the engine and adjusted the secondaries only to give me an idle of 1050.
* Fuel pressure reads at 6.5 (7 psi stock, but new, pump)
* Vacuum reads at 14 hg in idle (at 1050) and 5 hg in drive (at 560)
* choke is fully off.

Setting it at anything below 1050 caused putting it in drive to drop way to low (450) and the engine would stall. Putting it above 1050 caused it to start getting mechanical advance.

I have not yet played with any other components of the Holley (ex. jets, power valve etc).

So questions:
* what controls the space between the idle rpm and drive rpm? how do I get the drive rpm to go up but leave the idle rpm at 1000?
* I am noticing that the idle is not always stable. It is stable during a particular run but if we stop the engine and turn it back on again it will run at 1150 next time so I have to adjust the secondaries again and the another time it will be at 1450 (mechanical advance kicked in) requiring me to adjust the secondaries again - any thoughts on why this happens?

Thanks for all your continuing help!
PS. Ordered the Holley Carburators book by Dave Emanuel. I'm sure that will help with the understanding. Should be in later this week.

Cheers
Gary

[cobalt327]

Originally Posted by ggevaert

CDminter59, I did call MSD and they basically said that I am modifying a distributor in a manner that is not recommended for that particular unit so they can help me. They recommended I go to the adjustable one. Lol, was what I expected.

Cobalt327, that is the procedure I followed and listed next.

Ok, progress on the Holley.
* idle timing continues to be at 18 with a medium spring in the distributor that kicks in at 1200.
* got the primary and secondary transfer slots set at 0.020 and reversed the secondary transfer slot screw so I can adjust it on the fly.
* Started up the engine and adjusted the secondaries only to give me an idle of 1050.
* Fuel pressure reads at 6.5 (7 psi stock, but new, pump)
* Vacuum reads at 14 hg in idle (at 1050) and 5 hg in drive (at 560)
* choke is fully off.

Setting it at anything below 1050 caused putting it in drive to drop way to low (450) and the engine would stall. Putting it above 1050 caused it to start getting mechanical advance.

I have not yet played with any other components of the Holley (ex. jets, power valve etc).

So questions:
* what controls the space between the idle rpm and drive rpm? how do I get the drive rpm to go up but leave the idle rpm at 1000?
* I am noticing that the idle is not always stable. It is stable during a particular run but if we stop the engine and turn it back on again it will run at 1150 next time so I have to adjust the secondaries again and the another time it will be at 1450 (mechanical advance kicked in) requiring me to adjust the secondaries again - any thoughts on why this happens?

Thanks for all your continuing help!
PS. Ordered the Holley Carburators book by Dave Emanuel. I'm sure that will help with the understanding. Should be in later this week.

Cheers
Gary

Sounds like the torque converter is too tight.

[ggevaert]

Sorry, not following?

[cobalt327]

If the engine has to idle so high that it's on the verge of (or is already) idling on the transition circuit, and the engine rpm drops way down when the transmission is engaged, the torque converter- if too tight- will cause the rpm to drop. This is uber common w/any sort of performance camshaft in combo w/a stock stall speed TC.

Another thing that can do this is if the mechanical advance is already adding timing at idle speed (very possible if you're idling at an abnormally high rpm), when it's put into gear, the drop in rpm causes the timing to drop as well. The result is the idle speed drops too much.

Have you checked to see what the timing does when out of gear compared to when in gear? What are the cam specs?

[painted jester]

Carb Tunning

This may help with your questions and save me a lot of typing!

Jester

[ggevaert]

Hello,

I still don't get what you mean "torque converter is too tight", you mean 1500 vs 3500?

t-slot on primary was setup at 0.020 and left there, idling was adjusted on secondaries only so would it be on the transiotion circuit? I did confirm that fuel starts dribbling down the primaries at 1950 rpm so that should be the transfer from the idle to main fuel circuits is and is way above where I'm working.

Also, I have been keeping a careful eye on the timing the whole time I'm doing this. It is set at initial 18 degrees and the springs installed (2 mediums) cause timing to come in at 1300 (vacuum is disconnected and plugged). As noted above, I did see the mechanical come in when the secondaries were too open but when I get it down to 1050 idle it runs at 18 degrees idle so, in my mind fine.

I have not checked the timing out of gear vs in gear; will do that tomorow.
Cam specs are: Comp Cams 450 lift, 224 duration, 206 lobe centre

Painted Jester, that is one of the articles I have followed when building my own procedure. I have not yet gone as far as modifying the PCVR's, jets, PCV's, etc as I want to work through where I'm at first (once I drill there is no going back). Next step is the air/fuel mixture but first I need a stable idle based on idle transfer slots. Based on what I've been reading I should be ok but, like Cobalt327 says, there may be other factors involved I will need to study up on.

Thanks and keep the information coming!
Gary

[ggevaert]

Never mind, found looser/tighter torque converter articles online so you are saying that I need a higher, numerically, torque converter. Ok, will look into that next.
Thanks

[cobalt327]

Setting the t-slot "square" and then setting the curb idle using the secondary is NOT how it's done. I don't know how BS like this gets passed around and somehow becomes a fact.

I see you've got another thread running on all this. Good luck.

[painted jester]

Originally Posted by cobalt327

Setting the t-slot "square" and then setting the curb idle using the secondary is NOT how it's done. I don't know how BS like this gets passed around and somehow becomes a fact.

I agree strongly!!!

Jester