Mildly modified 318 PCV valve selection

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Sifting through the dialog. What's the issue? Idle speed?
 
toolmanmike said:
Sifting through the dialog. What's the issue? Idle speed?
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I’m really not sure anymore. Lol

Seriously though, it started as me asking about pcv valves, which brought about questions from people if my carb and timing settings were ok.

My vacuum at idle is stupid low for this combo. I just can’t seem to figure out why.

I’m just trying to figure it out without making anyone angry. Lol
 
And my idle speed is higher than it should be.

But I swear, my 950/750 idle speeds according to the tach sound more like 500-600 by my ear. Seriously low.

And I think our trans issue might be a front pump. I’m hoping to pressure test it Wednesday.
 
Running too rich? Have you done a fuel pressure check? There seems to be a lot if that going on lately.
 
toolmanmike said:
Running too rich? Have you done a fuel pressure check? There seems to be a lot if that going on lately.
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Doesn’t seem to now that I put in the 4.5 PV.

Cleaned up the idle in gear a lot.

But still doesn’t explain why such a small cam has that low of vacuum
 
prorac1 said:
Doesn’t seem to now that I put in the 4.5 PV.

Cleaned up the idle in gear a lot.

But still doesn’t explain why such a small cam has that low of vacuum
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My 273 doesn't either. Except for cam timing (advanced) there is no reason.
 
It's not the cam that wants 20* it's the compression and cylinder pressure. That 318 is an 8.5:1 motor at best. Coupled with that camshaft, and your cylinder pressure is lower than normal. This is the reason it wants so much timing. Pull the timing up and leave it there. Does it run good there with no spark knock? Yes? There's your answer. All the forum geniuses in the world cannot tell you what the engine wants. It will tell you itself and is trying to. The PCV system is normal and fine. Spend time worrying about something you're really having trouble with, because the PCV valve and the timing ain't those things. You clearly have the timing figured out. Didn't the vacuum signal increase when you pulled initial to 20*? There's your evidence the engine wants the increase in timing. Just remember to keep the total limited. You are going to have to play around with that until you find the sweet spot. Some like 32. Some like 36. It all depends. As long as there's no spark knock, it wouldn't bother me to see close to 40. I never worry too much with total as long as there's no spark knock. Good luck.
 
I agree with RRR except for one thing
Your high idle is aggravating the TC and the only way to get it down is to pull timing, and fix the vacuum.
So if your car was in my shop, I would be doing a Leakdown test to make sure the valves were closing, on account of 298 degrees is a huge advertised spec for such a small cam. And valves not closing 100%, will cause a low-vacuum as the piston forces just-inducted mixture back up into the intake manifold. The proof IMO, is that it won't idle at 650 in N/P where it should. And if it did idle at 650, you wouldn't be having a 200rpm drop into gear.
Of course your cam timing could have something to do with that as well.
 
First thing I would do is yank that 390cfm , with all its air bleeds,power valves,secondary spring, accelerator pump cams bs,and sell it to the /6 crowd.
Slap on a box stock Ede 600cfm, turn the a/f screws out 1.5 turns and burn rubber down the street. You will futz with that Holley more than an English motorcycle.

In regards to the pvc. Shake the later model one you have on there, and get a more period correct one. PCV valves aren't designed all the same.
 
Johnny Dart said:
First thing I would do is yank that 390cfm , with all its air bleeds,power valves,secondary spring, accelerator pump cams bs,and sell it to the /6 crowd.
Slap on a box stock Ede 600cfm, turn the a/f screws out 1.5 turns and burn rubber down the street. You will futz with that Holley more than an English motorcycle.

In regards to the pvc. Shake the later model one you have on there, and get a more period correct one. PCV valves aren't designed all the same.
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Yep what he said! I used to own a Triumph! LOL^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
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