[Xtreme70SS396]

http://store.summitracing.com/partdetail.asp?part=NAL-12568782&autoview=sku

Gen VI 502 short block, with hydraulic roller cam and provision for mechanical fuel pump.

Per Summit: "The cam has 0.527 in. of intake lift and 0.544 exhaust lift, with 110 degrees of lobe separation. Duration at 0.050 in. of lift is 224 degrees for the intakes, and 234 for the exhausts."

#1 - I thought short blocks did NOT come with a cam-
#2 - how would this combo, if it does work out that way, work using my cast iron heads, enlarged valves, with 107cc combustion chambers due to unshrouding?

Any thoughts welcome - I'm trying to keep the budget under control on this one, and was planning on using everything I could off my 402.

 

[mr 4 speed]

Mark,If you used the heads off of your 402 (especially if they have 2.19/1.88 valves) you would have one potent street car that would be good for very low 12's IMHO
I use this rationale based on the performance of my 454 (12.56 @ 108 MPH with a mild 223/231 @ .050 f/t hydraulic cam and 3.31 gears) with the big valves.
The seat of the pants performance with my car is very entertaining on the street to say the least :thumbsup: and it idles enough to let you know its got something but you are not sure what

 

[GRN69CHV]

That is the shortblock for the ZZ502 motor. A set of closed chamber ovals (107CC) will push the compression to about 9.8-9.9/1. This version of the 502 comes with the ZZ502 cam and includes the factory lifters. You will need to change the oil pan. This block requires an electric fuel pump. Check out Pace Perfromance, you can get the 454 shortblock (comes without the cam/lifters) if you want to run a mechanical fuel pump.

 

[69-CHVL]

Not worth it for 4500.00+ and then shipping

You will probably want to change the cam (another 300.00). Motor is not percision balanced, pistons down the hole, and then there's the ever-popular low tension rings. No fuel pump boss either, and pan needs changed out as mentioned.

Other than that it nice.

 

[Xtreme70SS396]

Good point about the mechanical fuel pump, hadn't thought that one out...

I kind of think the ad is a misprint, though - the fact that it includes the cam doesn't make sense for a shortblock.

SOOOOO, looking at Pace as another alternative:
http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=26944
This is the 454 engine shortblock. Has similar issues as the 502, but has a mechanical fuel pump provision, which I prefer for the look of the car.

Accessory bolt holes are a larger size - 7/16 instead of 3/8...

Timing cover is painted black, block won't accept a timing cover suitable for a double-roller chain without some drilling and tapping.

FREE Shipping!!

Looks like I would need a suitable camshaft to make it work, with an expected compression same as stated above using my heads - somewhere aroung 9.8:1

Will accept the factory hydraulic roller setup, so I could probably run the standard ZZ502 cam with it. Or maybe even the Voodoo that Vince runs above.

Thanks for the input so far, guys!

I've been trying to get someone local to just build up my 402, but the few that start to respond quote an initial price the same as buying a crate 454. Having no luck finding anyone that seems to want the work - so I started the inevitable search for other opportunities.

 

[69-CHVL]

Mark,

I would think for the 3700.00 price for the 454HO shortblock you could probably get a 496 shortblock built. The 454HO uses low-tension rings, and the pistons are down in the hole .020 so your compression will be lower than what your thinking.

The cam I'm running required my pistons to be notched which was not a pleasent situation.

Read some of the recent threads I had going, pretty explain this motor in detail and all the issues that had to be overcome.

 

[GRN69CHV]

I went to the PACE site again for the heck of it. It does state the 502 shortblock as having the mech fuel pump provision, this is different than before. I wonder if GM made this change.

As for the 454 HO, you can get a ZZ502 cam take-out for cheap (I have one here that I only pd 75.00 for it) which would be plenty for a decent street 454 motor. OE lifter sets are only about 150.00. GENVI timing sets are plenty stout (I run one in my current roller motor), cost is around 45.00-50.00. The stock piston notches will work with the smaller cam and especially if you only have 2.19 valves. There is a lot to consider.

 

[RATtyCamino]

Just a thought..

If you don't have a good block to start with, and want a GenVI style block for the 1 piece seal, then go with a GM bare block. It's PN 12561353 and is the block that comes with the 454HO. It has a fuel pump boss. If I was going to go that route, I'd buy the block and put a 4.25 stroke rotating assembly in it. That way you get the best of both worlds....496 or so cubic inches, fuel pump boss, one piece seal and the block is half of what a dart "M" block costs. This also allows you to run your piston and ring set of choice so you are not restricted on what head you can run or leaving you stuck with a less than optimum ring style.

Bill

 

[Xtreme70SS396]

Great info so far, thanks.

Maybe my best bet would be to call Pace, if they do the shortblock assembly themselves I could probably tailor it a bit more for my needs. Worth looking into I suppose, as I'm not having any luck around here. Not that I've stopped looking.

I'm more interested in an assembled shortblock - I don't have the time or inclination to do that all myself, so my setting up a 496 is pretty much out. I've been trying to get people around here to respond to engine build requests, with very little interest. I think the crate motor market has kept the prices low to the point they can't or don't want to compete with it.

The price difference between the 502 shortblock and 454 is also a factor, but the 502 would certainly keep the door open for future changes.

 

[69-CHVL]

502 is about 1000.00 more, but if you factor in the cam and lifters it comes with, and the balancer/flexplate, seems to be a little better of a deal.

Not to mention ~50cu in more which translates into 50HP/50ft lbs of torque. I don't think you'll get that much HP for that price (so long as the fuel pump thing isn't an issue)!

 

[69-CHVL]

Mark for 6689 Summit has the complete ZZ502. Sell your 402 if its a good runner and put it towards a complete motor. You have to remebember that the little things add up (heads bolts, rockers, gaskets)...this will put you closer to the ZZ502 than you think. And again, even if it costs you a couple of bucks more, how else can you get that much more HP for this cheap? Were talking aluminum heads here!!

Just another option.

 

[RATtyCamino]

Great info so far, thanks.

Maybe my best bet would be to call Pace, if they do the shortblock assembly themselves I could probably tailor it a bit more for my needs. Worth looking into I suppose, as I'm not having any luck around here. Not that I've stopped looking.

I'm more interested in an assembled shortblock - I don't have the time or inclination to do that all myself, so my setting up a 496 is pretty much out. I've been trying to get people around here to respond to engine build requests, with very little interest. I think the crate motor market has kept the prices low to the point they can't or don't want to compete with it.

The price difference between the 502 shortblock and 454 is also a factor, but the 502 would certainly keep the door open for future changes.

If you want a customized GM short block, check out Scoggin Dickey. http://www.sdpc2000.com/

I've purchased quite a bit of stuff from them over the years and they have been great. They work with a top flight machine shop in the area that will balance/blueprint any of their shortblocks or crate motors. They will customize pretty much anything they have.

For about $500, they will take that 502 short block and completely go through it. They will deck the block and hone it with a torque plate, degree the cam, balance, and re-assmble with better bearings.

Bill

 

[Xtreme70SS396]

All of these are good options, which just makes the decision that much harder....

I started thinking shortblock because I've got some good stuff on my 402, but I could easily swap them between motors. (Stewart water pump, powdercoated Holley, polished bolts, etc) The holley would work better on a 454 than a 502, and may need to be altered anyway. It is a good runner, I'm sure I could get something for it. (not numbers matching, so no concern there).

Heck, just the ZZ454 is a pretty good engine and would represent a nice improvement over what I have today, and I've seen those online for $5,600 fully assembled - I'm sure Summit would match that price. While I'd love the extra with a 502, I'm trying to control myself and not shell out the extra $$ right now.

I'll go check the scoggins site now.

 

[JC70SS]

Mark my engine shop up her ein Milwaukee has a 502 short block that is less than 1 yr old. Let me know if you are interested.

-Joe

 

[Xtreme70SS396]

Thanks, Joe, another contact would be great.