Top End Miss

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YA might want to fudge it just a little higher..Or Try leave a little room to shim it up if you need to...
 
Did you look at K-Motion springs?
Might need to cut the pockets and shorten the guide for the stem seal?
 
How much spring you will need is in part dictated by the shape of the cam lobe (profile) and RPM. You could always go to a little less rearend gear also,lol.
 
pmarvetz said:
How much spring you will need is in part dictated by the shape of the cam lobe (profile) and RPM. You could always go to a little less rearend gear also,lol.
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if i can go faster with the 4.88's why would I?? i never go faster than 45mph anywhere i drive anyways where i live so it dosn't matter... and i live 25 minutes from the track...

and yes i know spring pressure is based on ramp slope, engine rpm, boost, and some other variables...

EDIT: may go higher if the car likes it... will up to a 30 or 31" tire as well though...
 
racerhog said:
Did you look at K-Motion springs?
Might need to cut the pockets and shorten the guide for the stem seal?
Click to expand...

i would have to cal lthem as their website is kinda weird lol... but im looking for a 1.5 out side Dia with a minimum .995 (roughly from what i remember) inside Dia... and a 400-420 rate...

being i have a max installed height of 1.7 its gonna be tricky i think getting a 350ish open and not to stiff of a seat...
 
PSI Also Dose a great job helping with valvetrain issues....

http://www.psisprings.com/

If I recall... 340 Dual springs would fit... ONLY if you cut down the guide and also you have to cut down the spring pocket... They were good to like.... .490 lift or there about...
I think "Racer Brown" was were I got the Info.... But I cant find it out in my shop..... Figures.... Sheesh
 
805moparkid said:
ok for giggles opened it up to .025... it wouldn't start... then .020 and it wouldn't... so it looks like .016 is it...
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That doesn't seem right to me since you are using an MSD box.
From what I understand the Mopar pickup is basically the same as the MSD pickup and MSD recommends a setting of .018" to .030"
[ame]http://c452191.r91.cf2.rackcdn.com/images/bccx/image/84661_frm30015.pdf[/ame]
That being said those pickups have a permanent magnet and over time that magnet can lose some of it's strength which will result in a weaker trigger signal.
 
kman521 said:
That doesn't seem right to me since you are using an MSD box.
From what I understand the Mopar pickup is basically the same as the MSD pickup and MSD recommends a setting of .018" to .030"
http://c452191.r91.cf2.rackcdn.com/images/bccx/image/84661_frm30015.pdf
That being said those pickups have a permanent magnet and over time that magnet can lose some of it's strength which will result in a weaker trigger signal.
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well it is what it is lol... that fact is that its not gonna hit now so it should be fine...
 
racerhog said:
PSI Also Dose a great job helping with valvetrain issues....

http://www.psisprings.com/

If I recall... 340 Dual springs would fit... ONLY if you cut down the guide and also you have to cut down the spring pocket... They were good to like.... .490 lift or there about...
I think "Racer Brown" was were I got the Info.... But I cant find it out in my shop..... Figures.... Sheesh
Click to expand...

cool cool... will give them a call... i REALLY dont want to pull the head and do machine work again yet... lol
 
I ran Crane doubles sold for the LA engine on mine with my .530" (before lash) Isky solid. I might see if I can find one of the leftover springs and test it. I doubt they were #400 open pressure springs. Thats a ton for the small valves in a slant. I couldn't tell you where mine floated, I never had it happen, and I pinged it off 7K a few times.
 
That's what I'm thinkin. I mean I know valve spring pressure is important, but damn, 350 pounds is a ton. I wouldn't dare go to 400 +.
 
StrokerScamp said:
That's what I'm thinkin. I mean I know valve spring pressure is important, but damn, 350 pounds is a ton. I wouldn't dare go to 400 +.
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the spring rate maybe 400 but at installed its not anywhere near there... just like my 354's i have now only have just over 300 open... i wouldn't do 400 open either lol...

racerhog said:
I'm more worried about the valve failing than I am the spring rate for the RPM....
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well i have good stainless valves...
 
SpeedThrills said:
Sounds like you don't have enough volume. I found this: http://forums.corvetteforum.com/c1-...5-hi-volume-mechanical-fuel-pump-testing.html
About half way down the first post he mentions how much fuel you should pump for a given car. He's talking faster, more powerful cars, but it seems you're right, the 60 gph you're seeing isn't enough.
New parts don't mean good parts. Go through your delivery system closely.
I don't have anything running to do a test on. You know anyone whose car you could test to compare?
Click to expand...

MORE crickets! -I'm not sure why I'm still tryin'.
 
SpeedThrills said:
MORE crickets! -I'm not sure why I'm still tryin'.
Click to expand...

The first series of tests involved the Barry Grant style 1-gallon test. Essentially the BG 1 gallon test is a measurement of how much time it takes to fill a 1 gallon container with fuel as delivered to your carburetor(s). His site states that a 12 second car should fill the 1 gallon container in 35 seconds, 30 seconds for an 11 second car, and 25 seconds for a 10 second car. I ran the first 2 systems twice and the third was run 3 times. All tests were performed with the Holley 12-454-25 mechanical fuel pump. For #2 and #3 the existing fuel system up to the Holley pump was eliminated with the 12’ of hose/line coming directly out of a 5 gallon container and feeding into the Holley pump.

So using there logic for a 14.0 second car it should be about 45 seconds...

Now i have to admit i messed up on my volume test last time... i had the regulator at what i though was "open" with the screw all the way out... well these are like a bottle regulator so all the way out is closed lol...

so that could have been why my numbers were so bad... also ive only had the reg a week or two so its not the miss cause... will try another test wensday...
 
A quick thought, what are you using for feeler gauges when setting the gap in the distributor? I believe it has to be something non magnetic. I believe using regular steel feeler gauges screws either the pick up, or the reluctor up some how.
 
BBBCUDA said:
A quick thought, what are you using for feeler gauges when setting the gap in the distributor? I believe it has to be something non magnetic. I believe using regular steel feeler gauges screws either the pick up, or the reluctor up some how.
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brass but i was told by my carb guy its just for better feel...
 
ok so i rechecked the fuel volume on the black pump set at 6psi... it now flows in at 38 seconds per gallon! much better...

and will be picking up the 750 holley today...

so now i guess i should play with lash and see if that does anything?
 
Yeah put the valve lash back where the card says it needs to be. I think you're gettin close dude.
 
ok so got the carb back... installed it and ran like a charm...

so i went and tried lashing the valves back to what the cam card said... opened them to .024/.024 hot from .016/.020 hot and ran it... had about 2" more vacuum at idle for the same rpm and maybe a half inch more at cruse...

but still missing...

so now what...
 
805moparkid said:
ok so got the carb back... installed it and ran like a charm...

so i went and tried lashing the valves back to what the cam card said... opened them to .024/.024 hot from .016/.020 hot and ran it... had about 2" more vacuum at idle for the same rpm and maybe a half inch more at cruse...

but still missing...

so now what...
Click to expand...
So I guess you mean it runs like a charm, but it still misses? A little confusing.
Glad you got your volume up, one less thing to wonder about.
 
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