Hotting up a 502 Crate

[user-612937456]

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?

Randy

Yes but but with regards that the induction and exhaust system is not choking your newfound potential as well as proportional
increase in fuel/air supply to support increased expected output

[wyrmrider]

but it's most likely not going to be the same in both intake and exhaust
at all lift points?
not a chance
your camgrinder will want to see flow at all lift points
do your ports get with the program at low lifts?
or are they dead at low lifts?
affects overlap crossflow and backflow considerations-- Intake open and exhaust close, lift rates, (at certain piston speeds- piston draw) rocker ratios, etc
mufflers or open headers- do we get any draw at overlap?
but don't get ahead of yourself

[user-612937456]

Everything wrrmrider said this question has a very complex answer.

If you want to blend the bowls and port match the intake it will probably compliment your combo but if you do much more than that this is where it gats complicated this is where i consult a cam grinder. At this piont i say decide to what extent you want to port your heads then consult mike or someone like with your flow#'s and aplication

[randy331]

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?

Randy

Yes but but with regards that the induction and exhaust system is not choking your newfound potential as well as proportional
increase in fuel/air supply to support increased expected output

I disagree. I don't think gaining ex cfm on the flow bench is, any indication the ex port is better on the running engine. I've made ex port changes with no flow gain that increased the power of the engine. So what'd the bench tell me there?

And looking at just cfm on the intake side is no indication it will be better either.

And if you think having your "flows" in your hand when you call a cam grinder will get you the right cam the first time, your living in lala land.

Randy

[wyrmrider]

Having them in had will get you closer
especially on a non familiar build

[randy331]

Having them in had will get you closer
especially on a non familiar build

LOL. Whatever you say.

Try this. Call the same cam company several days apart, with the exact same combo but different "flows" and then you will know exactly how "flows' impact cam specs. Then report back to us with your findings so we will all know too.

Then call several cam Companies with the exact same combo AND "FLOWS" and see how close they are. They should all spec the same cam since they all had the "flows".

Randy

[wyrmrider]

Just pick the cam at the bottom of the page then go one size bigger and be happy
then change your valve seat angles to get it to work
call the big cam-grinders tech line LMFAO
BTW I'm going to try steeper seats on a coming up build
have to rethink everything
thanks for the prod

[bigjoe1]

Every time I get involved with one of these 502 crate engines, nothing seems to help unless you RAISE the compression. They never even have the rated compression ratio as they come from the dealer-- The 9.70 ( 502 HP engine ) in always down around 9.1 or 9.2 to one ----NOT GOOD--- Cam and increased CFM flow make very little difference unless the compression is increased


JOE SHERMAN RACING

[user-612937456]

LOL. Whatever you say.

Try this. Call the same cam company several days apart, with the exact same combo but different "flows" and then you will know exactly how "flows' impact cam specs. Then report back to us with your findings so we will all know too.

Then call several cam Companies with the exact same combo AND "FLOWS" and see how close they are. They should all spec the same cam since they all had the "flows".

Randy

I see you subscribe to getto scientific analysis. "Call the same cam company several days apart" Did you say off the shelf one size fits all?
or did you say go to autozone and give them a different symptom days apart and what do they try to sell you each time "Lucas!!" Do I need to explain marketing and incentive to maximize profit?

#1 marketing rule for a corporate salesman is to sell you what we have not what you really ask for and need. (not saying you can get a salesman that will if you request and give him the data will design and sell you a custom grind)

I disagree. I don't think gaining ex cfm on the flow bench is, any indication the ex port is better on the running engine. I've made ex port changes with no flow gain that increased the power of the engine. So what'd the bench tell me there?

And looking at just cfm on the intake side is no indication it will be better either.

And if you think having your "flows" in your hand when you call a cam grinder will get you the right cam the first time, your living in lala land.

Randy

I agree with what you disagree with If you take the small minded approach? But if you look at the larger picture of if you change the flow characteristics other items may need to be optimized to benefit.

Case in point you take a stock SBC 350 engine and put AFR 245's on it it will probably preform worse don't mater what cam grind you use. Leave the heads stock and use a better cam and wa-la you make more power. Does this prove your point?

Ok then put the AFR's back on, put an air gap intake with a 850 DP holly, the better camshaft, and 1 3/4 long tubes and you will probably make better power it may not be as drive-able but it makes more horsepower. Now put a more bigger more optimal grind and you will make even more power and maybe better drive-ability for what you purpose the radical engine for.

So minor changes in air flow may not require a different lobe profile but significant changes I airflow will benefit from a more optimal grind.

Does giving your AF #'s with all the other data guarantee a perfect grind not necessarily but you will get a better grind than if you give him no head data at all

[user-612937456]

Every time I get involved with one of these 502 crate engines, nothing seems to help unless you RAISE the compression. They never even have the rated compression ratio as they come from the dealer-- The 9.70 ( 502 HP engine ) in always down around 9.1 or 9.2 to one ----NOT GOOD--- Cam and increased CFM flow make very little difference unless the compression is increased


JOE SHERMAN RACING

I agree and disagree 2 points in compression with the right cam can make a sig increase HP but with the 9:1 comp and a totally different cam that optimizes VE and you will make some good HP #'s too even tho 12:1 comp will make better HP than the 9:1

It really depends on the ultimate goal and purpose of the power-plant. Not every car is an all out open headers dragster some may be for a not so radical street machine with much better drive-ability manners if it has 12:1's in it will need more overlap to bleed off comp for street-able octane fuels and close overlap means a radical sounding cam with higher RPM power-band. so 9:1's may be better for certain applications and still be capable of making impressive HP #'s

[Caprimaniac]

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

All good Points there.

It's mainly 1/8 and 1/4 mile, but he don't want to make the car impossible to drive on the street; heat, lumpy cruising etc. Getting it the 10's in 1/4. He has a gearing issue as well. Converter need a different stall speed.

As Joe stated; compression. He's swapped pistons and are now 11.2 static.

The car/ engine has got a great deal of attention; carefully changed and modified parts and getting faster every time. He's into something, but lack that last 0.5-1 second....

He's on leaf springs and 315 tyres. Has a loose front end aftermarket setup. Some goodies at the rear too, but I haven't looked at the details yet.

Thanks

[randy331]

LOL. Whatever you say.

Try this. Call the same cam company several days apart, with the exact same combo but different "flows" and then you will know exactly how "flows' impact cam specs. Then report back to us with your findings so we will all know too.

Then call several cam Companies with the exact same combo AND "FLOWS" and see how close they are. They should all spec the same cam since they all had the "flows".

Randy

I see you subscribe to getto scientific analysis. "Call the same cam company several days apart" Did you say off the shelf one size fits all?
or did you say go to autozone and give them a different symptom days apart and what do they try to sell you each time "Lucas!!" Do I need to explain marketing and incentive to maximize profit?

#1 marketing rule for a corporate salesman is to sell you what we have not what you really ask for and need. (not saying you can get a salesman that will if you request and give him the data will design and sell you a custom grind)

I disagree. I don't think gaining ex cfm on the flow bench is, any indication the ex port is better on the running engine. I've made ex port changes with no flow gain that increased the power of the engine. So what'd the bench tell me there?

And looking at just cfm on the intake side is no indication it will be better either.

And if you think having your "flows" in your hand when you call a cam grinder will get you the right cam the first time, your living in lala land.

Randy

I agree with what you disagree with If you take the small minded approach? But if you look at the larger picture of if you change the flow characteristics other items may need to be optimized to benefit.

Case in point you take a stock SBC 350 engine and put AFR 245's on it it will probably preform worse don't mater what cam grind you use. Leave the heads stock and use a better cam and wa-la you make more power. Does this prove your point?

Ok then put the AFR's back on, put an air gap intake with a 850 DP holly, the better camshaft, and 1 3/4 long tubes and you will probably make better power it may not be as drive-able but it makes more horsepower. Now put a more bigger more optimal grind and you will make even more power and maybe better drive-ability for what you purpose the radical engine for.

So minor changes in air flow may not require a different lobe profile but significant changes I airflow will benefit from a more optimal grind.

Does giving your AF #'s with all the other data guarantee a perfect grind not necessarily but you will get a better grind than if you give him no head data at all

Where did marketing get involved? You guys are saying call the cam company with flow helps get the right cam, I'm saying no it doesn't.

My "small mined approach" was developed when I started doing my own testing.

And Comp may have good marketing, but I don't have any trouble getting the exact lobes I want on the lsa I want, and no one mentions shelf cams to me.
I spec my own cams, you just keep your "flows" handy when you call the cam companies.

Randy

[swatson454]

Nah, there aren't any important algorithms based on head flow during the overlap period or anything. Just throw a bunch of cams at it, move them all over the place, change the rockers a half-dozen times and call it a day

[wyrmrider]

Then you can spec your own cams
helps if you are building great running 383 chevy's
randy has a combination that works exceedingly well

[swatson454]

Then you can spec your own cams
helps if you are building great running 383 chevy's
randy has a combination that works exceedingly well

I do and his 383 is a beast, no doubt about it.