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Confused on power valve sizing

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#61 ·
try 31f & 35 rr
 
Discussion starter · #63 ·
Ok went up 3 sizes havent been able to drive it due to rain.

Changing the rear accel pump to a 30cc

Have a pump cam kit

Anyone know what size cam I should put in there? THink I had a pink one in but it felt flat before dont know if I should put that one in again with the larger squirter or use a larger cam? Which one?

In feeling flat it felt like it was a big two barrel hardly felt much when opening the secondaries.:confused:

Yes I checked the linkage to make sure they are opening.
 
#64 ·
cuisinartvette said:
Ok went up 3 sizes havent been able to drive it due to rain.

Changing the rear accel pump to a 30cc

Have a pump cam kit

Anyone know what size cam I should put in there? THink I had a pink one in but it felt flat before dont know if I should put that one in again with the larger squirter or use a larger cam? Which one?

In feeling flat it felt like it was a big two barrel hardly felt much when opening the secondaries.:confused:

Yes I checked the linkage to make sure they are opening.
Click to expand...
Start with a #35 shooter & the pink cam on the #1 hole.:thumbsup:
 
#65 ·
troposcuba said:
just a question... you are talking about jetting and power valves, but said you have only run it in the garage for 15 minutes. unless something is way off, the power valve and jets should not even play into your mixture with the car idling or running with no load on it. maybe a little if you are revving it up in neutral, but that is not the way to tune it anyway.
Click to expand...
Here is fact.

If you line the cams up all together you'll see the different profiles, some come in early, some in the middle, some late.

So the cams set the "squirt curve" and its volume. The squirters are like restrictors. Bigger ones will let the entire vol of the squirt thru quickly, the smaller ones put a delay on the total squirt volume.

So dialing in the pump shot is managing /optimizing that combination for each particular engine.

If your rear transfer slot is **just** showing, and you get the pump shot on the secs dialed in, you should feel no hesitation when you tip into the secondaries.

Keep up the good woirk. Reminds me of when I dialed in my first Holleys after a 20 yr hiatus. Off and on, off and on....but the results were well worth it.
 
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Discussion starter · #66 ·
Thanks...Getting better little at a time.

Motor sounded real lopey after upping the squirters, moreso than before.





Now this one I took this morning after changing the advance curve. I had both light springs in the dist. Put one regular one in and left the light one, got rid of some of the higher rpm lope and has more power.
Just rolling into it some and just cracking the secondaries, no WOT. At 2.08 sounds like it breaks the Mickeys loose a little for a moment. So far think Im headed in the right direction. THINK!:confused:

Next Ill retime it adjust the valves one more time and go back to the carb.

Keep the tips coming bound and determined to get this right.

Right now 72 front jet, 82 rear
6.5 PV
31 front squirter up from 28 and rear 35 up from 31.
 
#67 ·
Watch those light springs, they will often make the advance come on AT IDLE, esp if you're idling at 1000 rpms or so.

The only way to set timing is to set TOTAL ( vaccum off), at rpm, and then when you drop it back to idle check the initial.

Beautiful scenery on the vid, as compared to SNOWVILLE ( which isnt Buffalo right now oddly) BTW, the idle sounds TOO SMOOTH! ;)
 
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Discussion starter · #68 ·
Youre right think the advance was coming in too soon. The car seems to want more fuel now or at least responds to it. Ill retime everything next few days that Im off and go from there. Once I upped the squirters with the light springs at 1700-1800 it acted like it had a motor vibration worried me! Once I changed the spring it went away, learning here.

Now I just have to figure when to stop going up in squirter size?
 
#69 ·
When the hesitation is gone, no need to go up further...

If you were to go to the track with slicks, you might still need a larger shooter - but doubt you'll need 3 sizes bigger on the street, and IMO 1 or 2 sizes bigger would be splitting hairs.
 
Discussion starter · #70 ·
No real hesitation but I do notice when I "just" touch the gas in neutral or when I go to ease it into gear theres a slight hesitation

Could that mean it needs a diffferent cam? Has the pink one on the front now.
Have a box of them I bought just dont know which to use and grow tired of experimenting unles I have a good idea of what will work.

Thanks:beers:
 
#71 ·
get the timing straightened out before tuning the carb to get rid of the light throttle hesitation.


>>> "Motor sounded real lopey after upping the squirters, moreso than before."

you trying to say changing the squirters changed the idle?
 
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Discussion starter · #72 ·
Squirters didnt change the idle/quality but the area in that 1600-2200 range or so sounded "lopey" so to speak like in the first vid on this page whereas before it was smoother. Guessing the increased fuel combined with too much timing caused it?
 
Discussion starter · #73 ·
Put one medium spring back in the dist along with one light spring and the lopiness around that range cleaned right up, car runs much better all the way around starting to make a lil power.

plan on putting the white cam up front and the stock pink one out back, getting closer. Car runs Ok shot feels a touch weak on the primary side though.


From stacking the cams up white seems to be the next largest? Appears like the shot would come on stronger sooner but rest of the curve matches the pink one which hoping is what I want.. :confused:
 
Discussion starter · #74 ·
Got a vacuum leak so carb has to come off. Starting on the secondary side of the carb, will put the 30cc pump back on and put the pink cam in.

There are 3 holes on that assembly, which it the stock one, see 2 holes on the cam.

Looked at the front cams last night couldnt make heads or tails of which to use. Car runs good off the primary but still seems like it could use a little more inital shot other than that its Ok. Which one to try?
 
#75 ·
Online search of the pump cams gives you a great idea of which cams to try - look at the color vs how quickly the shot comes in. Sounds like you need a color that comes in quicker than what you have now - see the chart below and go from there.

Image
 
Discussion starter · #76 ·
Yes come in sooner....Im confused on the degree thing on that pic.

Cant figure which one to use, make a suggestion maybe? (next step up from pink) :beers:



Also did notice while trying to adjust mix screws they dont seem to have much effect. Car started idling higher today. Checked carb base nuts those are tight.

Vaccum leak or maybe blown power valve?
 
#77 ·
I'd jump to the blue cam - I've always had good luck with it, and the differences on the other cams are just too small.

I've found that tiny changes to the mixture screws have a big effect on MPG if not on idle quality - but in my last 2 engines, they didn't like to idle as well that lean. If you're not noticing a difference, keep them about 1.5 turns out.

If you have to change the position of the butterflies with the idle speed screw, you can affect the transfer slot, which can in turn throw everything off again.
 
Discussion starter · #78 · (Edited)
Got it.

Ok just put the 30cc pump in the secondary (used pink cam in #1 hole like stock), and on a recommendation from Holley tech moved the pink cam in front to # 2 meaning put the screw in the $2 hole and lined it up hope thats right. If thats not enough Ill try the blue one.

Also put a 4.5 PV in there just to try it.

. Just upon firing up seemed to feel a bit better but who knows. Soon as traffic dies down Ill take it down the street.

Edit: Got back, my legs are shaking this thing is starting to make some power!

THere is a slight momentary hesitation when opening the secondaries, lean?
Suggestions?

ALso wondering if should switch back to 6.5 PV sounded a little more cammy than it did, Id think with the smaller PV it would be cleaner?:confused:
 
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