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tell me why

1K views 12 replies 6 participants last post by  wld bil 
#1 ·
1972 long wheel base chevy truck, 350 .030, balanced roatating assembly, flat top pistons, .272/.454 cam, 67cc pro topline straight plug heads, Holley duel plane intake, Holley 600 carb, Hei distributor, turbo 350, 1800-2400 stall, 373 gears. Tell me why I can't out run a 86 long wheel base pickup truck that has a rebuilt 305 with a .268/.454 cam, 570 Holley carb, 3.08 rear gear.
 
#2 ·
???

Maybe the guy your running has one of those 400 cubic inch 305's....... L.O.L.

What is your et and what is his???? How about mph???

If your racing on the street ( and you should not be doing that) is he getting you aff the line or on the big end????

Keith
 
#3 ·
Re: ???

k-star said:
Maybe the guy your running has one of those 400 cubic inch 305's....... L.O.L.

What is your et and what is his???? How about mph???

If your racing on the street ( and you should not be doing that) is he getting you aff the line or on the big end????

Keith

We're on a country road. He beats me everywhere. What horsepower am I looking it with that motor combo I have. I know his is a 305, his stock heads have had a little work.
 
#4 ·
Is the Holley 600 a vacuum secondary type? If that's the case then maybe you have too stiff of a spring in there. Try going to a lighter spring to make sure the secondaries are opening. (or you could use the dreaded "cheater screw" and force the secondaries open) :mwink:
 
#7 ·
johnsongrass1 said:
His must be tuned better than yours. A lot better than yours.

I got my valves set correctly. The carb is a brand new 1850s 600 vacuum secondary carb. I bought it, and they said bolt it on, set the floats and go. The floats ended up being set correctly. The timing is set at 10 degrees (it has a vacuum advance distributor). It has a stock type distributor in it. When I first put the distributor in, and ran the motor, it would not go. After removing the cap, and rotor, the counter weights were stacked on top of each other. After separating them it decided to run. What would cause that? Do I need a new distributor, if I do, what kind at a reasonable price.

Here are the specs on what that carb has in it. Primary metering jet is 66, secondary metering jet is 9 plate*, pump discharge nozzle is 0.025, primary power valve is 65, and secondary diaphram spring is plain silver. I don't know what any of this means, but if any of you know what might could be changed to help it, please let me know.

Also, right now it has about 8" diameter, by 1.5" tall air fliter(temporary) on it, 1 1/4" headers with glass packs, stock plug wires, ac 45ts(i think) plugs, and Holley Contender dual plane intake. What filter, exhaust, plugs, wires, and intake change would benefit me more in this 1972 truck. I don't know what that intake is good for, or the equal to as far as an Elderbrock goes. Would K&N filter, 1 1/2"Hooker exhaust, ACCEL wires, ??? plugs help any.

What would a shift kit do for the 350 tranny. This is a daily driver/still want it to run a little better truck.

After saying all of this, this truck is running real smooth, and nice right now. I know after all, this is a big truck, just want to help it all I can.

killerformula said:
is yours a 4x4?

wait, does he have a 700 R4? That would help him out quite a bit-
It's not a 4x4, and I don't know what his tranny is, but he did say he had a shift kit.

I think I wish I would have stroke this engine. What would a 350 block bored .060 over with a 400 crank be? How much more money would it have cost me as far as the block work goes. The 350 rotating assembly I got out of JR Motorsports went from $599 to $899 for the 383 set.
 
#8 ·
.060 350 block with a 400 crank is a 388, I'm building one right now (except this dufus from texas is draggin *** on my intake:rolleyes: ).

I don't think that's the problem, your motor should have plenty of power, before you rip it all apart do some checking and tuning. Use and advance timing light to see what your total timing is, and try adjusting the weights in your distributor. How big are your tires? Bigger tires are going to kill your launch. You should be making good power all the way up to the high 5000 range with that setup.

Did you inspect those heads? MANY problems have been reported with PTL heads. How is the idle on this thing? How much vacuum do you have? Give us some more info, do some checking.

Another thing you might check is your voltage to your coil. Make sure its getting an honest 12+ volts of juice all the way through the RPM band. If it starts dropping off, you might not be making the power.

Most importantly (re-reading your post) what kind of exhaust do u have on this thing? Exhaust is what ties the whole motor together, without it, your cam is working against you. You'll need headers (1 5/8 should work) and duals (2.5 inch is as far as you need to go).

K
 
#9 ·
killerformula said:
.060 350 block with a 400 crank is a 388, I'm building one right now (except this dufus from texas is draggin *** on my intake:rolleyes: ).

I don't think that's the problem, your motor should have plenty of power, before you rip it all apart do some checking and tuning. Use and advance timing light to see what your total timing is, and try adjusting the weights in your distributor. How big are your tires? Bigger tires are going to kill your launch. You should be making good power all the way up to the high 5000 range with that setup.

Did you inspect those heads? MANY problems have been reported with PTL heads. How is the idle on this thing? How much vacuum do you have? Give us some more info, do some checking.

Another thing you might check is your voltage to your coil. Make sure its getting an honest 12+ volts of juice all the way through the RPM band. If it starts dropping off, you might not be making the power.

Most importantly (re-reading your post) what kind of exhaust do u have on this thing? Exhaust is what ties the whole motor together, without it, your cam is working against you. You'll need headers (1 5/8 should work) and duals (2.5 inch is as far as you need to go).

K

I hate to sound dumb, but I don't know what total timing is. I don't knon anything about adjusting the weights in the distributor. 275 60 on the tires. I didn't inspect the heads, I order them through a machine shop though, maybe he did. If there is a problem, is there any way to find out while the motor is together. It idles great, and I don't know how much vacuum. I haven't checked my voltage to my coil. It has 1 1/4' headers with glass packs. I thought about 1 1/2" Hooker headers(I didn't know if 1 5/8" would fit) with some type of flow master. Where could I take it to get total timing, adjust weights, and chaeck vacuum.

I would love to learn these things, and will if I could watch someone who knew what they were doing. I love this forum, it has really helped me a lot. I hope folks don't get tired of me asking ????. Maybe someday I'll be the one with the answers.
 
#10 ·
I think you should try changing the vacuum secondary springs on the carb. The silver spring that the 1850's come with is pretty stiff, and doesn't let all four barrels open as soon as most people want them to. Here is a link to the jegs site that sells the spring kits.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=837&prmenbr=361

For $10.00 it's worth trying out. Go to the lightest spring in the pack, and work your way back from there. Listen to the carb as the engine revs to make sure the secondaries are opening up at about 3000 - 3500 RPM's. That should give you the best all around performance.
 
#13 ·
Do you have a full 12v going to your HEI. HEI didn't come out until '73 as an option,and on all in '74, (pretty sure). Your '72 came w/points originally. Shoot your power wire for the didtributor, should be a 12g wire with 12 volts w/the ignition on. If it was converted and is stiil using the small resisted wire originally used with points (6 volts), your HEI will not work to it's full potential. Check this site for further insite.

http://www.oldengine.org/unfaq/hei.htm

Hope this helps!:cool:
 
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