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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
dont bother with factory vortecs, its not if they will crack, but when they will crack. check out Blue print engines 190 cc intake heads, for the cost of a new set of vortecs and the machine work to be able to use a slightly bigger cam, you can get a new set of these aluminum heads that do flow slightly better and can already handle the extra lift right out of the box and shave weight off the front end for under a grand.
Last edited by fullsize fun; Oct 20, 2017 at 08:16 PM.
dont bother with factory vortecs, its not if they will crack, but when they will crack. check out Blue print engines 190 cc intake heads, for the cost of a new set of vortecs and the machine work to be able to use a slightly bigger cam, you can get a new set of these aluminum heads that do flow slightly better and can already handle the extra lift right out of the box and shave weight off the front end for under a grand.
I brought a a l31 block and vortec heads to my builder for a 383 stroker build. he said he'd check them out and see if they're cracked and if they aren't cracked the machining costs for them to take the extra lift would be more than a set of aluminum heads like those. they were dart pro 1 copies and they looked great. the vortecs ended up not being cracked and I went with the aluminum heads.
So, long story short, don't clean the rust from a block by leaving the block in vinegar for a week.
Anyway - picking up a 98 Vortec tomorrow. Guy says oil and coolant mixing. Is this likely to be cracked heads? What should I look for?
Anything to look for in general?
It's a complete pull out with all accessories, etc.
Going to turn it into a 383. This time I'll choose a different cleaning method.
GD
Magnetic particle inspection is standard inspection for cylinder head reconditioning and will be performed before any other head work other than disassembling and cleaning. Most shops can and will pressure test with water to. If your shop doesn't do this you need another shop. It reads like your trying to do what the shop should do. My suggestion is find a shop you can trust.
Can you please elaborate on cleaning the block with vinegar?? I have wondered if that could be made to work at home but it would take a very large container and a whole lotta vinegar. At home I clean all my iron small parts by a 2 day soak in vinegar. But never over 2 days. I think it could work for blocks but haven't got there yet. What I like is goes down the drain when done as it's eco friendly - and it works pretty darn good to on iron parts. Tried it once on magnesium valve covers but it killed those valve covers and used a bunch of vinegar to.
So what happened with a full week soak on a block???
Bit of a sludge factory but nothing the parts washer can't handle.
Definitely an intake gasket failure.
GD
Looks like someone never changed their oil! But for $200 that's as good as it gets and if you sell all accessories/unused parts you should get alot of that back.
So what happened with a full week soak on a block???
Heh. It heavily pitted all the surfaces - and the rust scale in the coolant jackets wasn't all gone yet even after a week. It damaged the lifter bores to the point they would have to be sleeved... If that's even possible.
I think the vinegar attacked the carbon in the cast iron. Basically turned it into a porous sponge looking surface. Pretty ugly.
I think with the level of rust that was in the jackets on that block.... well a different method would be needed for sure. Something that definitely cannot attack cast iron. I'm no chemist (obviously) but apparently mild acid is out....
Looks like someone never changed their oil! But for $200 that's as good as it gets and if you sell all accessories/unused parts you should get alot of that back.
The gentleman I got this one from has at least 4 more for the same $200. In Portland, OR. Really nice guy - he's disabled and parts out full size Chevy's in a big shop behind his house. Loaded it for with his forklift even. I figured $200 is a steal. I'll use the vortec heads and serpentine drive on my 69 GMC truck. Block for my Trans Am, and sell off the late model Vortec intake..... or could I use that on my truck with something like the FAST EFI? Hhhhhmmmm.
I measured the cylinders - out of round and taper are all within a thou. I'm just going to drop in some stock sized forged pistons and run it - no honing. I might do the mainline and have some 4 bolt billet caps installed. Probably change out the cam bearings. Leave it at that.
GD
Last edited by GeneralDisorder; Oct 22, 2017 at 01:57 PM.
Dude at least run a ball hone down the cylinders so new rings can seat.
I have a LOT of experience in that area. Honing is a HUGE mistake that will only result in excessive wear, oil burning, and power loss. The rings will seat great on these bores. You'll see
At home I clean all my iron small parts by a 2 day soak in vinegar. But never over 2 days. I think it could work for blocks but haven't got there yet. What I like is goes down the drain when done as it's eco friendly - and it works pretty darn good to on iron parts. Tried it once on magnesium valve covers but it killed those valve covers and used a bunch of vinegar to.