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Hotting up a 502 Crate

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Hotting up a 502 Crate

Postby Caprimaniac » Thu Jul 24, 2014 5:09 am

Hi, fellas.
My pal has a 65 Chevelle which go to the strip, both 1/4 and 1/8 mile. In the 3100lbs region, and a light prepped auto. Currently 11.5 in the 1/4.
Engine is stock besides carb, which is pro- built for dragracing this car/engine/trans combo. Exhaust has 1 straight through muffler on each side, 2,5 or 3"- can't remember...

Anyway. Without changing heads or bottom end, what would be an easy route to more Hp?
Keep the intake, or does it need to be swapped to a single plane or other?
Will the heads benefit from any light home- porting?
I'm guessing a hyd roller in the 240-250 @.050- region and 0.50- 0.55" valvelift w/ matching springs & maybe lighter valve components, rockers and lifters?

Would swapping to good aluminum heads give much?

I'm a noobie to GM- stuff besides what i read on here and other forums. I found some lues in the thred below. Was sure i've seen multiple threads on crate 502 and hotting up for circle track on here, which could have interesting info, but didn't find them at first try.
viewtopic.php?f=1&t=22904&p=253384&hilit=Crate+502#p253384

Currntly enjoying warm weather & summer holiday at the coast. Thnks. RuneS
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Re: Hotting up a 502 Crate

Postby gvx » Thu Jul 24, 2014 5:54 am

Is this a strip only car? What is the rear gear? What tires and do you think you can put more power to the ground?

of course a top end and a cam is where the HP is. $4000 will get you 700 plus HP but how much do you really need? A $400 custom ground cam may net you a 80 Plus additional HP depending on your converter and how radical you can stand the idle.
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Re: Hotting up a 502 Crate

Postby swatson454 » Thu Jul 24, 2014 8:35 am

I just clicked on three different "502 Crate" engines and got three different intake valve sizes and two different cams. What are your valve sizes and what cam did it come with? Also, what rpm are you looking to peak at?


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Re: Hotting up a 502 Crate

Postby Caprimaniac » Thu Jul 24, 2014 8:55 am

Thank you, guys.
I'll have to ask my bud for the details.

He's launching on 315/75 (if i remember correct) @ 4-5000 somewhere. Drivetrain not ideal, but not bad either. @ 1.52 60- feet. Mostly strip, some street. Not looking to invest 1000's in it. Just some fidling about, like cam, porting, maybe intake and carb.

Before I figure out the details, the capabilities of the heads are unknown. I guess a 100 Hp gain as a target. From the stock 500(?).
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Re: Hotting up a 502 Crate

Postby gvx » Thu Jul 24, 2014 9:40 am

Sounds like you can easily meet your goals with light porting job, port mach the intake, a semi aggressive cam and make sure your exhaust is correct. Probably 31" 1 7/8's primarys and collector length can tuned to draw out a fer extra peak HP's

You need to post ALL the details from the carb through the headers inc. stall, trans, and final drive ratio. There are some really smart cam grinders here that will suggest a good cam grind for you. You may want to get your porting work done first so you can post the flow#'s this will be beneficial in calculating a cam grind.

Also decide whether 1/4 mile or the 1/8'th is where you want to dial in the engine package unless you are swapping diff's for each track.
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Re: Hotting up a 502 Crate

Postby F-BIRD'88 » Thu Jul 24, 2014 1:16 pm

A basic plate nitrous system and a separate dedicated supporting fuel system for that.
Buy a system like the NOS Cheater system.
Add a msd timing retard box for timing reduction
On nitrous runs

150-180hp will chop 1 full sec off the et and add 10-12
Mph.
May need to upgrade present valve springs as the car will mph abd traat higher
Rpm.

This is how you reach your goal within budget.
Its basic, reliable and VERY EFFECTIVE for the budget
And goal.
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Re: Hotting up a 502 Crate

Postby Caprimaniac » Thu Jul 24, 2014 3:45 pm

F-BIRD'88 wrote:A basic plate nitrous system and a separate dedicated supporting fuel system for that.
Buy a system like the NOS Cheater system.
Add a msd timing retard box for timing reduction
On nitrous runs

150-180hp will chop 1 full sec off the et and add 10-12
Mph.
May need to upgrade present valve springs as the car will mph abd traat higher
Rpm.

This is how you reach your goal within budget.
Its basic, reliable and VERY EFFECTIVE for the budget
And goal.

This doesn't sound stupid at all, F-bird....
Really like the idea of using NOS as power- adder. The historic "correct" way to do it, if not a valley compressor supercharger fit the plan. We need to discuss this over a cold beer, me and my pal. But i fear he want to go pump gas- on motor.
Well. Here's some details:
www.chevrolet.com/performance/crate-eng ... eluxe.html
11.2 sc, dome pistons
242/252 .612 110 lsa
Launch 5200, shift 6300
Th400
3.73 rear end, 30" tall 315.

Estimated Hp 565, from weight/ET
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Re: Hotting up a 502 Crate

Postby rfoll » Thu Jul 24, 2014 3:55 pm

Probably some room for improvement in the camshaft dept. I have run larger cams on motors with 100 ci less. If the exhaust is 2.5", the motor is being choked. If the chart from the link is correct, you may be over revving it a bit.
So much to do, so little time...
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Re: Hotting up a 502 Crate

Postby Caprimaniac » Thu Jul 24, 2014 5:42 pm

Yeah, well; he told me valve float at 6700. Shifting at 6000/6300

I'm not sure if springs are stock or not, but i figure- with that cam- it'd need springs.

I'll have to dig into the contents of this motor to figure more details.
Thanks all, for input.
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Re: Hotting up a 502 Crate

Postby Caprimaniac » Sun Jul 27, 2014 4:01 am

Hi.

After some Reading, it looks like the 12363390 heads on this motor is not holding him back. A light porting as mentioned, maybe. But what about a valve- job? Maybe some to be gained there?

This 502 has Performer RPM manifold and 1 3/4" headers.

Has a 1" carb spacer and 2" headers on the shelf, waiting to be bolted on.

As I understand from what I've read on here, the 2" headers might be too much, and 1 7/8 would be a better option?

What about a Victor Jr single plane. Would it Wake up the motor? As I see it, any intake would need some - or alot of porting as well...Or what?

He's determined to go N/A on pump gas.

Thanks.
RS
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Re: Hotting up a 502 Crate

Postby wyrmrider » Sun Jul 27, 2014 12:39 pm

how about a clue as to usage/ application and chassis, drivetrain, tranny gears, tires
remind me what bore and stroke is and what those heads are- oval port or peanuts or what
motor together and installed?
you need to run what you brung to as best as possible, get it all dialed in before making changes
timing, carb, plugs
then
try your spacers, adv and retard the cam, simple things
take good notes- your motor will tell you what it wants
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Re: Hotting up a 502 Crate

Postby randy331 » Sun Jul 27, 2014 7:48 pm

gvx wrote: You may want to get your porting work done first so you can post the flow#'s this will be beneficial in calculating a cam grind.

Will more cfm = more duration/lift, or less??

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Re: Hotting up a 502 Crate

Postby wyrmrider » Sun Jul 27, 2014 8:44 pm

it depends, are you going for more rpm
also your intake/ exhaust ratio will change, which affects your rocker and cam choices (and compression)
if the motor is together run it to get some baselines
then do the port work first
If apart get grinding
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Re: Hotting up a 502 Crate

Postby gvx » Sun Jul 27, 2014 9:01 pm

randy331 wrote:Will more cfm = more duration/lift, or less??

Randy

In this case he needs a larger profile any way. And considering the purpose is the same But in theory porting Influence on optimal cam grind depends on balance of improvement of IN/EX if the % the exact same or was one better. If improvment was proportional I think change in optimal cam grind will be minimal with minor porting. Even tho significant increase in port volume this may change this assumption.

I may be out in left field with my statement as this is just my general understanding of basic theory hopefully one of the cam grinders will check in and validate or help reshape my understanding
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Re: Hotting up a 502 Crate

Postby randy331 » Sun Jul 27, 2014 9:15 pm

gvx wrote: But in theory porting Influence on optimal cam grind depends on balance of improvement of IN/EX if the % the exact same or was one better. If improvment was proportional I think change in optimal cam grind will be minimal with minor porting.

So the same gain on in/ex as measured on a flow bench means the in and ex are both proportionally better on the running engine?

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