Thread: 502 combinations

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I am wondering if I am going to get into trouble running the following combination on my Gen VI 502 with stock valve reliefs: I think Ill be ok but just wanted to double check.

AFR 325cc Magnum heads (119cc chambers) with crane cams powermax hydraulic roller cam:

Grind Number: HR-226/345-2S-12 IG
Operating Range: 2500-6000 RPM
Duration Advertised: 288° Intake / 298° Exhaust
Duration @ .050'' Lift: 226° Intake / 236° Exhaust
Valve Lift w/1.7 Rockers: .587'' Intake / .610'' Exhaust
Lobe Separation Angle: 112°
Max Lift Angle: 107° ATDC Intake / 117° BTDC Exhaust
Open/Close @.050'' Cam Lift: Intake - 6° BTDC (opens) / 40° ABDC (closes)
Exhaust - 55° BBDC (opens) / 1° ATDC (closes)


Also, crane cams reccomends 9.5-11 compression ratio. I think the best i can do is closer to 9. Is this an issue?

Any good 502 combinations out there? Looking for 600+ hp

you may be ok BUT i wound check valve to pistons clearance if you take some one word what said it is ok you are a fool. and with a head change to i would for shure check it. why are you running the 325 afr heads?i think for the cc runner on the heads and the 0.50 is small on the cam with the big runner heads. the cam stop 6000 and the head will go past that . to make good use of the heads i think a small roller soild cam would take the rpm that the heads will see .i know you will need more cr for the bigger cam. i think the cr and the cam is good but the heads are big for you com the 502 could take some more dura @0.50 but that is what i think .big engine low cr small cam good air speed smaller cc heads = torque .big cc heads hi rpm more cam more cr hirer hp and rpm

you hp many be 573 at 5500 and tq595 at 4500 with the cam you have and 9to1. hp many be less and the tq hard to say to many variable

Jlem502, Sallee-chevrolet.com builds a 502 that puts out 630 HP & 605 TQ. They call it the Ultimate Street. Actually they have 3 versions of it. The other two put out something like 625 HP, don't remember exactly but check it out. It lists all the parts that they use in it. Also sdpc2000.com now has a 509 that puts out in the 600 HP range but I believe this particular combo used to be built using a 502 block....... Hope this helps ya, Bill

like i said you do not have the cr i think . SDPC sell a 600+hp crate engine but the cam has 236-244 @0.50 like i said i wound like to see in your engine .this engine has gm rec ports heads fully ported heads and the cr is 10.2-1 there is to many things that differ i can and i have built big block for a long time so at the end of all this is a dyno. not the desk top dyno. i can get a lot more hp but the cr is not rigth to make the hp BUT you have tq .TQ is king and you can make more with 9to 1 at a lower rpm than the hp with your engine . on the sallee SDPC crate engines? piston to wall .the deck hi . rings make? ring gap? how much head work ?what headers do you have? the same they run at the dyno? how about mufflerswhat make? how big how long? on the pipes x or h cross? do you have the same intake and carb that they do at the time of there dyno ? the rigth push rods and this is not done with some cheap $2. checker you get at auto zone get this wrong you could see a loss in power and the same rocker arms they use to .all the thing here can be 10 hp more or less each.and the tune in. and oil pan ? and the oil ?like i said to many variable

Salley builds a ZZ502/550 that has your cam in it plus hand ported ZZ502/502 heads (110 cc). I bought one and added a BG 870 cfm speed demon carb. I have not fired it yet ..........

Billsbird is right on their 630 HP 502 crate motor as well ...........

For an extra $~2500 you could add a roots or centrifugal supercharger and tack on up to 200 hp more fairly easily. I am looking at a Procharger blow-thru unit right now running at a modest 6 psig for my 9.6:1 502 to bump up another ~150 hp. But I will probably get over it ............

kitz

Originally posted by pat mccarthy
you may be ok BUT i wound check valve to pistons clearance if you take some one word what said it is ok you are a fool. and with a head change to i would for shure check it. why are you running the 325 afr heads?i think for the cc runner on the heads and the 0.50 is small on the cam with the big runner heads. the cam stop 6000 and the head will go past that . to make good use of the heads i think a small roller soild cam would take the rpm that the heads will see .i know you will need more cr for the bigger cam. i think the cr and the cam is good but the heads are big for you com the 502 could take some more dura @0.50 but that is what i think .big engine low cr small cam good air speed smaller cc heads = torque .big cc heads hi rpm more cam more cr hirer hp and rpm

What Pat says here.Way to much head.I would think it would be really soogy on the bottom end because of the size of the heads.

thanks for the input guys......i think im going to use the sallee chevrolet recipe.....seems to be exactly what im looking....high hp but streetable. Does anyone see anything to be cautious of? If not I am going to use most of those parts. Im going to start with the heads (going to buy them tonight or tommorow). Any last thoughts?

...yes, enjoy your Horse Power ... Bill

Can I through a stroker crank (4.25") and 6.385 rods with stock pistons in a stock 502 (making 533 cubes)?

Or will I be smacking valves?

You can probably stoke it easily, but not with the stock pistons....the pin height is different because of the longer rods. And yes, use the longer rods if you're going to stroke it. Pat will offer more on this. Im not terribly familiar with the 502 blocks, I have done many 454's of the older variety. I dont know if those earlier heads you mentioned would be too large of an intake runner on that engine....yes, they're big, but I run 327cc intake runners on rect. port heads on my 505 stroker, and I can tell you it's anything buy soggy at low rpms!! or any rpms for that matter. John

This is my first engine build and I am doing it peicemeal, buying each component individually. I have the Gen VI 502 block, stroker crank, OE pistons and rings, and will be putting stroker rods in soon - Will the stock pistons be pushing the heads off? I will find out soon enough. I know the pin height would be different, I guess I will find out how much an 1/8" means on the business side of the cylinder.

I am going to be running Brodix RaceRite Oval ports, and a mild Crane Cam. I want a very streetable ride.

1/8 and down round the crank this is where they may hit the counter weights of the crank back sid of the piston if you have .080 or so there then zip off your sticking up part of the piston this will only work with stock rod 6.136 and a 4.250 crank if it was down in the hole stock. and you shoot of o deck it may not be much more than 0.080 but you will have less piston to valve and more cr to