502 Crate Engine..

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gn69z28
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502 Crate Engine..

Post by gn69z28 »

Customer brings us a 502 crate engine. Gen 6. Oil pump pickup fell off and melted 1 and 2 rod bearing. Very low mileage engine. When pulling it apart it appears to still have factory markings on all bolts and main caps. Std bore. Engine has a .010 .010 crank and JE pistons with Edelbrock heads. The oil pan still has the GM part number sticker on it. Is this a GM crate engine and since it looks new why a .010 .010 crank. Is this normal practice to use a ground crank in a new engine? Owner just bought the car with engine already in it so doesn't know where engine came from.
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Re: 502 Crate Engine..

Post by prairiehotrodder »

Thats no Gm crate engine anymore. Maybe it was at one time. The more i hear about GM crate engines the less i ever want to own one. Last week at the track i heard a bunch of horror stories about a 720 hp 572 that was nothing but grief for the owner.
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Re: 502 Crate Engine..

Post by Frankshaft »

Is it a 4.466 bore? Je did make the pistons for those engines for Gm. They will have a goofy metric ring stack. If it's 4.470, then it has been honed .004 over. The actual Bore size "stock" is 4.466. It should have stock dimple rod with 7/16 bolts. The cylinder heads if they say Edelbrock Performer Rpm on the ends, they are not what came on zz502's. If they say Gm Performance Parts, but they are actually Edelbrock Performer Rpm roval ports, the difference is the Heads stamped Gm Performance parts come with a 2.25 intake valve, the edelbrock stamped heads, have a 2.19. Its possible thecrank was ground. I have gotten "Brand New" Howards Pro series 4340 cranks, their best crank, that are like $1400, with rod journals already ground .010, not sold as a blem, twice. Once discovered, they gave me a credit, because that's bs. But, that's the low down on the 502. It will also have stamped rockers.
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Re: 502 Crate Engine..

Post by Frankshaft »

prairiehotrodder wrote: Mon Jul 09, 2018 8:43 pm Thats no Gm crate engine anymore. Maybe it was at one time. The more i hear about GM crate engines the less i ever want to own one. Last week at the track i heard a bunch of horror stories about a 720 hp 572 that was nothing but grief for the owner.
You can build a much better 572 for the same money and make WAAAY more power, overhyped. Although, I like fixing them. Those and zz502's. Lame ducks. I pick the 502's up about 250hp, still run on pump gas. The 572's wake up about the same. I should add, I have a couple combos for the 502's. 680hp hyd roller version. The 250 hp gains are with solid rollers, and dominators. But still run on pump gas and can be driven regularily.
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Re: 502 Crate Engine..

Post by gn69z28 »

It is 4.466 bore and the heads are stamped Edelbrock Performer RPM. Rods are dimpled with 7/16 bolts. I don't have the rocker arms yet since the owner took the heads off before bringing it to me. But he said he may want to get roller rockers so that leads me to believe they are stamped steelthat was on it.
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Re: 502 Crate Engine..

Post by ProPower engines »

The 502 iron head engines use a positive stop stamped rocker.
The 502 marine engines used a roller rockers just FYI but the mercruiser heads on the 502/502 were made for them by edelbrock but were not stamped as such as far as I have seen but the proof is in the stem size as the street heads used a 11/32" stem and the marine heads use 3/8" stems.
Mahle sells a replacement piston set that is .005 over the std. 502 bore for those that want to freshen up with out boring and a rebalancing the crank and are a much nicer ring pak then the OE JE pistons use.
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gn69z28
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Re: 502 Crate Engine..

Post by gn69z28 »

I took the heads apart today. They are stamped Edelbrock Performer RPM on the ends. They have 11/32 stem valves with 2.25 intake valves. Looks like a small square port intake port.
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Re: 502 Crate Engine..

Post by PRH »

Sounds like it started out as either an iron headed long block that got the heads swapped on, or a 502 shortblock that was finished somewhere other than GM.

No real help with the 10/10 crank, but it wouldn’t totally surprise me if it came from GM that way.
Somewhat handy with a die grinder.
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Re: 502 Crate Engine..

Post by Frankshaft »

PRH wrote: Wed Jul 11, 2018 11:49 am Sounds like it started out as either an iron headed long block that got the heads swapped on, or a 502 shortblock that was finished somewhere other than GM.

No real help with the 10/10 crank, but it wouldn’t totally surprise me if it came from GM that way.
That's what I was going to add. It might have been a gm short block and they copied it. What's the cam in it?
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Re: 502 Crate Engine..

Post by gn69z28 »

I'm not sure who's cam is in it. It has the number 241350 stamped on the back end of it. It's a hydraulic roller. Measuring the lobe lift and multiplying 1.7 I come up with .535 valve lift.
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Re: 502 Crate Engine..

Post by PRH »

The iron headed motor should come with a .510/.540 hyd roller cam, the ZZ502 shortblock uses a .527/.544 lift hyd roller cam.
Somewhat handy with a die grinder.
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Re: 502 Crate Engine..

Post by gn69z28 »

Update... customer wants to make close to 600hp on motor and later put a small turbo on it. And a FAST fuel injection unit on it. I need a camshaft recommendation.. street driven 72 Chevelle. Not planning on turning over 6000 rpms. Wants a weekend reliable drive anywhere car. Thanks
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Re: 502 Crate Engine..

Post by Frankshaft »

Erson #E120208. Put it in +4. Do some mild porting to the heads, and you will be there. You can use the factory lifters and dog bone/spider set up.
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