Okay....I got the engine torn down partially,and here is what the insides look like.The pistons are .40 over flat tops,but unsure of the manufacture.The part numbers are 244P.
This engine has sat for a LONG time,but was pretty much.....no miles.It appears that water has sat in a couple cylinders,and started to etch into the cylinder walls.You can see it,but only feel it in one tiny area.I am going to pull the engine out,and freshen up for when I install the new cam,and the Brodix heads.I am hoping that I can just clean the walls up w/a hone,and install new rings,and bearings.
This is a 69 302,so I don't want to bore the engine,and use it.If something happened,then I lose the value of the block.If it can't be saved at 40 over w/a hone,then will build 70 truck 4-bolt,or a good 75 L82 that is over in the corner.
I have had a oil leak,and been unable to locate,and found a small crack on the intake,and a intake gasket that looks like it was sucking alittle air.My headlights have not wanted to go down here lately,and very slow going up????Is this the cause?
This is a shame,cause you can still very easily see the cross hatch where it was honed.It ran fine,and didn't burn any oil.
This engine was begging for breathing room.It has 65 #461 heads w/the original 1.94s,no screw in studs,solid lift cam,magnum style long shot rockers,and lock nut w/the allen head lock in the center.
Suggestions,and thoughts here fellas.
Thanks as always....

 

i bet a lite hone would clean it up enough.

 

For the shortblock, it's going to have to come all the way down for sure.

IMHO the safest route if the bores are within spec for taper and roundness but needs oversize would be a hone with a set of custom oversize pistons. This sort of thing used to be insanely expensive, but now they're not all that much more expensive than an off-the-shelf forged piston.

Should be a fun engine

 

Why do you say it is a 302. Those pistions sure are not 302 pistons nor are those heads you are talking about. Does it have a DZ on the stamp pad? The rest looks like it can be cleaned up. If it is a 302 just find another block and build it up. Does it have the 302 crank in it that has not been turned?

 

If you're concerned with the value of the block.. I'd sell it or stash it in the corner. If you continue to use it, you are going to continue to devalue the block even more. Also, if you are concerned about the value, sell the engine, and make a profit off its value. IMHO that block is no different than an L82 or any other high nickel block with the exception that it has a few numbers casted in it that says it belonged to a Camaro. If indeed it is a stroker, I'd take the rotating assembly out of it, stuff it in that 010 truck block or L82 block you got, sell the DZ block by itself, sell the rotating assembly out of either the truck block or the L82, and use the extra money for the car..

 

I tried shoving a bore mic thru my screen, but it didn't work.

 

Thanks for the comments.I was just trying to find the cheapest route to do this build.I have 2 good other engines over in the corner,and both run,but need gone thru.
The block has been decked,so no DZ stamp.I say it is a 302,cause it is a #386 block,and pulled the pan,and is a 4-bolt.Also,has the larger damper,and the 8" timimg chain cover.And the original builder said it was a DZ,but I still pulled the pan.Corvettes came w/#386 blocks too,but not 4-bolt.Only the DZ for 69.
I said the heads were 65 461s.NOT DZ heads.DZ heads would be 186s.This is a accumalation of parts,and was put together in the very early 70s.I'm going to sale the heads over in the C2 section.
Thanks for the thoughts,and will post more when I get the engine pulled.

 

Just right off from the pics........... They look like the TRW four valve relief forged pistons............. Very common 20 years ago or even the first KB hyper pistons.

All stock heads had valve spring caps and rotators retainers. Those might be titanium retainers. Chromoly are black. Back in the day before screw in studs. racers drilled a pin to hold the studs at higher spring pressures.

 

I just pulled the other head,and it looks like only water got into the LH side that I pulled first.The crosshatch is VERY visible on these cylinders.
This was a circuit car in the WOW in the 70s after it was built,and hasn't had alot of miles on it.the pitting is extrememly light,and hope that I can get away w/a hone.Alot also,depends on what the bottom end is.The builder said it was a stroker motor,but what was available in the early 70s for stroking a SB?When I pulled the pan....I didn't remove it.I dropped onside of the drag link to lower it enough to peek inside.It was killing me to know if it was a 4-bolt block,and it is.
I thought the pistons looked like the old TRWs too,but was unable to pull the number up?
The retainers do look titanium,and the spring look brand new.The heads were disassembled,and chromed,then put back together,but they left them as the 1.94s,so there is alot of breathing room left in this engine,or they left the 1.94s to try to develop some low end vacuum to pull signal for the induction.I don't know.
How much decking does it usually take to wipe a deck clean?How to I tell what the cc is for the top of the piston area,or do use a dial guage,and measure the distance from the top of the piston to the block,then figure in the heads ccs?The heads are brodix IK180s,and 64 cc.The machinist said they looked like they were decked too,and he trued them up,and suppose to let me know how they shake down cc'ed.
So....w/these pistons,and my heads...there is no way to pull close to 11.1?
The starter is DZ too,and has the green tipped dip stick.Other little things that are unique to the 302 for the 69 run.
Thanks as always.I have built engines before,but NOT a engine builder.I'm a half *** paint,and body guy,so ya alls help/imput is VERY much respected.

 

You said that you don't want to bore the engine but that it is already bored .040. If a hone will not clean up the pitting, why not go another .020 and get new .060 oversized pistons? Or if you want to retain the block, it could be sleeved if it is valuable enough to keep.
Terry

 

Terry...the block is now more of use to me as the 010 70 truck 4-bolt over in the corner,but......this engine to correct dated 69 Z28 is worth it's weight in gold.Even w/a decked front pad.These are very hard to come by.
If I can hone it,and use it,then I won't have to dump much more money into this ...which is VERY limited right now.If I have to go another 60,then I will just use one of my other engines here.This motor has been waaaaay tonned down,but I like rpms,and a 302 is right up my alley.I like R'ssssssss.

 

Yes you need to measure piston to deck height. It gives you quench and go ahead and figure out the stroke at the same time.

 

That casting was used from 68-74 , for 302,327, and 350. With the stamp gone, it could be any of those.

 

I don't know about to 74.I didn't see that,but...for 69(made in 68 for 69 run)....it is 302 290 horse 4-bolt,or 327 210 horse 2-bolt,and 350 4 bolt LT1.This is a 4-bolt w/a LATE 68 casting date for a 69 run.It's not 2-bolt,so we know it isn't the 327 that a few were still put in Camaros.They never put a LT in ANY 69 car,so we know it's not a LT1 350 for the 70 run(casted in 69),so......Am I missing something here?
Todays standards...this is a rare engine.When this car was built.....they were common.It was just toned down.Maybe trashed the engine,and that is why it is .40 over?Who takes a engine .40 over w/out reason?Guys bore them .30 over usually unless there is some cause to go larger.Bent rod?Broken piston?

 

The only reason to bore it that far oversize is that it's required to get it in spec. Could have been anything.

 

Engine is out.....I'm kinda at a loss for the direction to take.Owner said it was a DZ engine.Numbers check out,but the engine has been decked,so no front engine pad.Owner said it was a "stroker motor".Appears it is infact a "stroker motor".A 302 block,that very likely blew apart,and "stroked" w/the guts from a 350.Crank is cast 350.Balancer,starter,dip stick is from DZ.Block checks out that being a 4-bolt,late 68 cast.....302.
I don't know if I should try to sale this thing,or what.There's no manufacturer on the pistons belly.Just the part # on the top,and .040.Hmmmmm.Look at the rods.Polished to relieve the possibility of stress cracks?Remember......this was done in the early 70s.I am waiting for more info. from the builder.
Anyways,some suggestions w/the direction to take w/this engine?W/what I have......what can I do to pep this little burger up?Sat. we are going to St.Louis to pick up my heads from the machine shop,and the cam,etc.
Here's some pictures of the lower end,and someone was asking me about the exhaust some time back,so....

 

I believe a z-28 302 has the vin stamped above the oil filter, but it's faint. Take a look.

 

That is only true on SOME Z28s,or so the nastyZ28 board says.It says 386,and 371,I think.I will look again tomorrow,but pretty sure that's what it is.Most were on the front pad w/the DZ at the end of the call tag.
Thanks for your thoughts here.I have researched this engine,and researched it.The guy that built this car owns a big salvage yard,and has been building some of the most famous cars of the 70s show cars.he told me the engine was a stroked 302,and he had the 6x2 intake,and pulled the 427/400 horse,and went w/the SB,and had the exhaust made.
I will hopefully be talking to him right after Christmas,and he said that he has a packet of info. that he keeps on all his cars,but I have yet to receive this.

 

Those blocks are hard to find as that is one with the 2482 center caps which is the nodualr iron performance caps GM used only on a few applications, It looks like a cast crank.

 

The only way I was able to see mine was by taking digital pictures under bright lights, then zooming in on the pictures. The fact that it's not machined for a stamping doesn't help.

Merry Christmas Kevin,

I was looking for your intake and carbs in the Christmas giveaway thread.