PDA

View Full Version : 502 vs. 502



Carl C
01-19-2012, 09:45 AM
Is the new Mercury 8.2 L, 502 based on the same platform as the old 502 or is it a completely different engine that just happens to also be a 502?

VetteLT193
01-19-2012, 10:09 AM
Standard Gen VI block. same as the 525, etc.

Carl C
01-19-2012, 11:59 AM
"Standard Gen VI block. same as the 525, etc."

Wow, glad I got rid of my white elephant 496!

gcarter
01-19-2012, 04:11 PM
If you go on GM's parts site, that's what they are........
standard Generation VI.

Carl C
01-19-2012, 05:47 PM
"gm stopped casting the Big blocks and thats why the 496 is no longer in use,,i believe the block is casted from another source for mercury.."

It's my understanding that the 502 has always been a crate engine only. They are purchased and marinized by Mercury. Raw blocks are CNC machined in house for the Mercury Racing engines. I wonder how much cheaper they got the 496s for to make the change?

silverghost
01-19-2012, 07:28 PM
GM officially shut down the Big Block MK VI production line for good just after the U.S. government "bailout" of GM.

This Big Block Chevy Tonawanda NY engine production line had been in continous operation since 1965 with the first the 396, 427, 454 MK IV , MK V 454,502 , & MK VI 502.

I don't know if the tooling & machine equipment was saved; or if someone else will start building these big block iron engines~~~I doubt it ?

Just before the line was officially shut-down for the very last time Mercruiser Marine took delivery a a very large batch of engines & parts ; as did GM performance for their dealer's over the counter performance catalog .

When their all gone~~~
I suspect they will be gone forever .

gcarter
01-19-2012, 07:57 PM
If you look here, you'll see they (GM) are supplying BB crate engines in lots of flavors:

http://store.gmperformanceparts.com/store/SelectCat.do?catId=1775&prodsFound=1&redir=true&category=Big%20Blocks

Here the specs:
ZZ 502/502 Tech Specs







Block Part Number:


10237292










Block Type:


Cast iron with 4-bolt main caps










Bore x stroke (in):


4.47 x 4.00










Camshaft duration (@.050 in):


224 degree intake / 234 degree exhaust










Camshaft lift (in):


.527 intake / .544 exhaust










Camshaft Part Number:


12366543










Camshaft type:


Hydraulic roller










Compression ratio:


9.6:1










Connecting Rod Part Number:


10198922










Connecting rods Type:


Forged steel, shot peened










Crankshaft Part Number:


10183723










Crankshaft Type:


Forged steel










Cylinder head Part Number:


12363390










Cylinder head Type:


Aluminum oval port; 110cc chambers










Displacement (cu in):


502










Engine Name:


ZZ502/502 Base Engine:










Engine type:


Chevy big-block V-8










Ignition timing:


8 degree BTDC @ 800 rpm; 36 degree total @ 5000 rpm










Maximum rpm:


5800










NOTE:


Distributor with melonized steel gear MUST be used with long blocks and partial engines with steel camshafts, or engine damage will occur. GMPP distributor P/N 93440806 is recommended.










Piston Part Number:


12533507










Pistons Type:


Forged aluminum










Recommended fuel:


92 octane










Rocker arm ratio:


1.7:1










Rocker arms Part Number:


12368082










Rocker arms Type:


Stamped steel










Valve size (in):


2.25 intake / 1.88 exhaust; stainless steel






And they're available from $7,200.00 w/aluminum heads..

gcarter
01-19-2012, 08:16 PM
Here's one w/iron heads and a lower C/R:
These are available for about $6,500.00.

502 HO Tech Specs







Block Part Number:


10237292










Block Type:


Cast iron with 4-bolt main caps










Bore x stroke (in):


4.47 x 4.00










Camshaft duration (@.050 in)


211 degree intake / 230 degree exhaust










Camshaft lift (in):


.510 intake / .540 exhaust










Camshaft Part Number:


24502611










Camshaft type:


Hydraulic roller










Compression ratio:


8.75:1










Connecting Rod Part Number:


10198922










Connecting rods Type:


Forged steel, shot peened










Crankshaft Part Number:


10183723










Crankshaft Type:


Forged steel










Cylinder head Part Number:


12562920










Cylinder head Type:


Iron rectangular port; 118cc chambers










Displacement (cu in):


502










Engine Name:


502 HO:










Engine type:


Chevy big-block V-8










Flexplate Part Number:


10185034










Flexplate Size:


14"










Ignition timing:


36 degree total @ 3600 rpm, with vacuum advance disconnected










Maximum rpm:


5500










NOTE:


Distributor with melonized steel gear MUST be used with engines with steel camshafts, or engine damage will occur.










NOTE:


GMPP HEI distributor P/N 93440806 is recommended.










Piston Part Number:


12533507










Pistons Type:


Forged aluminum










Recommended fuel:


92 octane










Rocker arm ratio:


1.7:1










Rocker arms Part Number:


12523976










Rocker arms Type:


Stamped steel










Valve size (in):


2.19 intake / 1.88 exhaust










Water Pump Part Number:


12484890










Water pump Type:


Cast iron, long-style

farmer tx
01-20-2012, 12:38 AM
I thought I read that Mercury bought the tooling. I remember getting the last two LS-7 crate engines from Scoggin Dickey for $2700. apiece back in '88 or '89.

http://www.seabuddyonboats.com/boats/new-mercruiser-mercury-marine-engine-stern-drive-engine-380-hp-to-700-hp/

Carl C
01-20-2012, 08:59 AM
"I thought I read that Mercury bought the tooling. I remember getting the last two LS-7 crate engines from Scoggin Dickey for $2700. apiece back in '88 or '89.

http://www.seabuddyonboats.com/boats...-hp-to-700-hp/ (http://www.seabuddyonboats.com/boats/new-mercruiser-mercury-marine-engine-stern-drive-engine-380-hp-to-700-hp/) "

Interesting article but I don't think Mercury is building these engines. Maybe some misinformation? I think GM is still building them as crate engines.

silverghost
01-20-2012, 09:14 AM
The GM Tonawanda NY engine plant was the very last GM owned facilty building any big block iron Chevy engines.
There was a big deal made in Tonawanda NY when the very last Big Block engine came off the line.
It was also on the national TV news.

As I had mentioned earlier this GM plant, & the Big Block line, had been in continous production since 1965 .
GM & Mercruiser stockpiled most of these last batch of engines & parts off of this line.

It is now possible that someone bought the machine tooling, casting patterns, etc and restarted production at another site ?

~~~I know Mercruiser was very interested in doing this ?
GM & Mercruiser have had a very long working relationship history.
Mercruiser actually built ALL the very first limited production Corvette ZR-1 series engines .
The long awaited ZR-! was delayed at least a year and a half because Mercruiser had problems building these engines for GM/Chevy.
These first very limited production ZR-1 Aluminum High performance Vette engines had some real serious issues.
A friend of mine bought two ZR-1 Vettes new in this time period.
He actually drove one car~~~ while putting the other in long-term storage to speculate on it as a car collector.

Carl C
01-20-2012, 10:11 AM
They built the 'vette engines because of their expertise and facilities for casting aluminum blocks. Remember they've been building aluminum outboards for many years. Now to built a cast iron engine is a whole different thing and ttbomk Mercury does not have a foundry or facility to do this. Maybe the GM big blocks that went out of production were the ones used in GM vehicles? The 502 was never offered in a vehicle afaik.

Greg Guimond
07-19-2014, 09:21 PM
So where did things end up?

Carl C
07-20-2014, 06:38 AM
So where did things end up?

The 496 is history and Mercury is back to buying 502 crate engines from GM for their production engines with catalytic converters. I believe the "blue" engines still use raw blocks CNC machined in house by Mercury. http://www.chevrolet.com/performance/crate-engines/big-block-502-ho.html

gcarter
07-20-2014, 06:55 PM
FWIW, and there're folks here that know a LOT more about this than I do, Dart blocks are a world apart from GM blocks. I'm not a metallurgist either, but the iron in the Dart block I bought is the densest, most uniform cast iron I've ever seen. The gentleman that did the block prep told me there's very little prep work to a Dart block compared to a GM block. The outside of the block was pretty slick w/no snags at the parting lines.
I suppose Dart isn't planning on going out of business any time soon, so I don't see a problem.