502 Chevy 0 Hours

[Engreps]

Anyone have an idea on how much HP this combo will make????


$7,500.00

502 Chevy FRESH
502 Chevy Fresh rebuild Never cranked 0 Time

STD Rods STD Mains 9/1

Internal Balanced, Align Honed, New Crane Roller 139741, New Crane Gold Series Rockers, Reworked Rectangular port Cast Iron Merlin Heads, Weiand Team G air Gap Intake.
CV products engine stand and Carb lift plate..

I have $4000 in machine work. That does not include what I payed for the Crane Cam and Crane roller lifters..
I believe this engine is a gen 1V



Built by Joe Jefferson. He is know locally for building race engines.

REDUCED

$7,500.00 or best offer

336-210-8103

[MILD THUNDER]

575HP

[Ratickle]

I'd say he's dang close depending on carb and exhaust.

[600sci]

realisticly i say 530 HP !

[Engreps]

It was realy strong with the other cam. Should be more HP than before with the Crane cam. Never had it on a dyno with the other cam. Had no problem turning 6500. Ran about 88 MPH.

[MILD THUNDER]

6500rpm is pushing the limit if your using hyd lifters!

[C35]

There are hundreds of details about an engine build. That ad is missing most of them. Is it a stock GM steel crank? What rods? What rod bolts? What valves? Springs? Lifters? Pushrods? Those details are going to make the difference between a 6800 rpm 502 that will make that 575 and a Merc 415 with a bigger cam.

I've seen a bunch of people use the stock lifter on a more aggressive cam- they won't live long. Those are things you have to find out.

$4k in machine work? Maybe if they made a bunch of pieces from scratch. Or that includes the porting job at $2k to make a set of iron heads flow like a $2k set of aluminum heads. That one's a red flag to me- either a misunderstanding or a mis-speak. Either way, cause for concern.

An engine is only as good as its worst part. I had an engine apart last year that had a major failure due to the fact that the top-shelf builder with a national presence used a Chinese oil pump drive rod in a $62,000 blower motor.

It's not likely a "Gen IV". That designation is "Mark 4". And it would have to be an aftermarket block to be a 4. Then you have Gen V and Gen VI. You can quickly tell the difference between those two by counting the timing cover bolts.

A reputable high-performance engine builder is going to have a build sheet that includes every part with a detailed description and assembly notes, including clearance specs. Some of the "big name" guys don't do that- because maybe they can get away with it.

[600sci]

There are hundreds of details about an engine build. That ad is missing most of them. Is it a stock GM steel crank? What rods? What rod bolts? What valves? Springs? Lifters? Pushrods? Those details are going to make the difference between a 6800 rpm 502 that will make that 575 and a Merc 415 with a bigger cam.

I've seen a bunch of people use the stock lifter on a more aggressive cam- they won't live long. Those are things you have to find out.

$4k in machine work? Maybe if they made a bunch of pieces from scratch. Or that includes the porting job at $2k to make a set of iron heads flow like a $2k set of aluminum heads. That one's a red flag to me- either a misunderstanding or a mis-speak. Either way, cause for concern.

An engine is only as good as its worst part. I had an engine apart last year that had a major failure due to the fact that the top-shelf builder with a national presence used a Chinese oil pump drive rod in a $62,000 blower motor.

It's not likely a "Gen IV". That designation is "Mark 4". And it would have to be an aftermarket block to be a 4. Then you have Gen V and Gen VI. You can quickly tell the difference between those two by counting the timing cover bolts.

A reputable high-performance engine builder is going to have a build sheet that includes every part with a detailed description and assembly notes, including clearance specs. Some of the "big name" guys don't do that- because maybe they can get away with it.

i tent to agree !

[Engreps]

Ok believe it is a gen 4 Bow Tie block. Started life as a Bow Tie Crate motor.
All internal parts are GM Bow tie. Came is a Crane Roller 139741 I believe Crane said this came was good up to 6000 RPM. All bolts are ARP.
Push rods are Crane. Crane Gold Series Rockers. Heads are Rectangular Port Merlin which been worked. Valve spriings are Crane. Crank internal ballanced and all rods and pistons. Meaning the rotating assembly is ballanced. 4K was all machine work and assembly parts and assenbly of the engine. Cam, roller rockers and the zero ballance harmonic ballancer were extra charges.

When I was turning it 6500 was with a solid lift cam. Oh yes I for got to say. I have worked as a mechanic and fabricator on Pro Stock Drag cars also managed a couple mechanical shops. I have also a few NDBA patches for 150 mph in a quarter mile. This is not my first rodeo on marine engines.

Was just looking for an educated opinion on what people thought this engine would make for power. Not to be critised for not posting all of the internal parts list.

[600sci]

Ok believe it is a gen 4 Bow Tie block. Started life as a Bow Tie Crate motor.
All internal parts are GM Bow tie. Came is a Crane Roller 139741 I believe Crane said this came was good up to 6000 RPM. All bolts are ARP.
Push rods are Crane. Crane Gold Series Rockers. Heads are Rectangular Port Merlin which been worked. Valve spriings are Crane. Crank internal ballanced and all rods and pistons. Meaning the rotating assembly is ballanced. 4K was all machine work and assembly parts and assenbly of the engine. Cam, roller rockers and the zero ballance harmonic ballancer were extra charges.

When I was turning it 6500 was with a solid lift cam. Oh yes I for got to say. I have worked as a mechanic and fabricator on Pro Stock Drag cars also managed a couple mechanical shops. I have also a few NDBA patches for 150 mph in a quarter mile. This is not my first rodeo on marine engines.

Was just looking for an educated opinion on what people thought this engine would make for power. Not to be critised for not posting all of the internal parts list.

ok, gm stock internals...i say still solid 530-550 maybe
on hydraulic lifters i would not go over 5500 RPM !!!!!
compression is 9:1 so it cant be more then 550 HP
but probably very solid and rliable !

Not to critisize u in any way but C35's post was 100% on the money ...without knowing all the facts !
And also, that u have been involved in drag racing and building some engines for that matter...would if i needed one, absolutley scare me to buy this !

I had very very bad experience with darg/car engine builders that claimed they had build boat engines before..never lasted longer then 20 miles at WOT..but yeah..they shure made power for this short time !

:D:USA:

[C35]

Was just looking for an educated opinion on what people thought this engine would make for power. Not to be critised for not posting all of the internal parts list.

The "educated" entails knowing what's inside to make that assessment. No criticism intended. But no one can give you any sort of real number without knowing what parts are in the mix.

I also didn't realize this was your motor and that you were looking to sell it. But for what it's worth, what I asked would be all the same questions a potential buyer would ask.

[Engreps]

No problem Thanks for the response. The engine builder I used has lots of marine experiance. It was built for marine use not for a drag car..... I did not build this because I didn't have the time. I have always internal ballanced all big bloch Chevys that I have run..

[MILD THUNDER]

I have a buddy who had very similiar combo. 509CI, Merlin rect port heads, JE flat top pistons, 741 Crane cam ,dart single plane intake, and a 800 Holley. Made right around 600HP on the dyno, and 600FT lbs. GM cranks and rods.

Nothing wrong with the GM steel cranks and "DOT" rods. As long as its put together properly, and good fasteners are used. TONS of guys running around with those cranks and rods in blower motors making 700+hp.

A merc HP500 was rated at 470HP at the prop. On a dyno, they probably made around 500-510HP at the crank. That was with GM heads, and a milder flat tappet cam. 50-75HP is not out of reach with a better set of heads, and a cam upgrade.

If you were running a solid roller before, and turning 6500RPM, without knowing the specs, I'd still have a hard time believing this setup will make more power turning a safe 5500RPM with the HYD setup. However, it should be very user friendly and more reliable. I wouldn't feel comfortable turning a BBC marine motor to 6500, even with solids, and without a shaft style rocker system. Race motor is one thing, but a pleasure boat mill is another.

Sounds overall like a decent mill. Bowtie Block, decent heads, etc. Whether it makes 550HP, 575HP, or 500HP, its splitting hairs. Simple things like jetting, carb spacers, timing, air cleaner, header size, can make a 20-30HP difference on a dyno.

[C35]

The Merc 700sci is a 525 with a Whipple. All GM stock 502 HP parts. Put together correctly of course. People tweak that piece to close to 800.

[600sci]

all the above ..but i still say max 550 HP because with this cam u will not reach the rpm to make the power over 550 !

well u can..but not for long in a hyd. motor !!:willy_nilly: