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#48038 02/21/09 04:33 AM
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I am tearing apart my 250 and it is my first entire rebuild. Have everything taken out except the cam, and the head is staying together, as it is integrated and I plan on rebuilding it for a turbo setup once the funds allow in a year or so.

Basically this is to clean up everything so the next rebuild will be a tad easier and now I know whats inside the motor and have a little experience.

Anyway, I need to know what can be re-used and what should be replaced for sure. I know gaskets obviously, but is it ok to reuse old rings, bearings, bolts not TTY, etc?

The crank is huge! I will definitely be looking into knifing it and putting a billet steel flexplate in front of a 2500-3000 stall tq converter for the turbo setup.

I plan on letting some CLR sit on the bare block in the water jacket because there is a good deal of rust, and don't quite have enough for an acid wash.

Mostly the gaskets will be replaced, but for the 2nd time around, and I do search when I can, but what would be best to get the most efficiency for the turbo setup? I am not asking about the turbo itself, just what valve springs, alterations and modifications, things like that. I also realize forged piston heads are best, and the 1963 crank was the only forged crank according to my inline book.

I know some of these questions are answered, but nothing shows up recently so thought a refresher would be good.

Thanks.

neonova75 #48039 02/21/09 05:58 AM
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Neonova75,

How much boost do you plan on running? I'm in the same boat you are and I've read and heard it said by many that a stock 250 will easily handle up to 7 pounds boost, which is what I'm running.

Oblio


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Oblio #48040 02/21/09 10:11 AM
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I personally would never reuse old rings, they will usually spin in the cylinders and line up resulting in using oil or smoking. If you havent pulled the pistons and the engine didnt use any oil and has reasonable milage leave them in. Bearings are cheap and will also help to restore any lost oil pressure. Being you have the head off I would have it checked for cracks, they where prone to cracks. I am not sure if you are going to use this head for turboing, (personally wouldn't),in the interim of going to build for a turbo I would deck the current head just to raise the CR for a little better drivability while you put things together. If building down the road for turbo I would also consider getting another block and do the build up on it vs downtime on your current project. Motors can be had anywhere from $50 & up and no sense wasting money going back through your engine again since you are not doing a full rebuild this time, if you are going to use this block for you turbo build and it has a lot of milage on it then it will need to be bored, hot tanked etc and going turbo possibly forged pistons, your current setup will not need an expensive flywheel or any other exotic peices (stall converter) do these when you are ready to go that route, peformance of a stock motor with a 2500/3000 stall would be a waste of time, money, and no real performance gains.

67 Bowtie #48045 02/21/09 06:38 PM
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I don't want to use this head for the turbo, which is why i don't really care about it honestly, lol.

I plan on honing and acid washing the block later, to keep it as close to numbers matching. I may consider getting a 292 to build up if I find one for cheap, but I also want to keep the turbo setup as economic as possible, part of the project, and i'm not sure of the 292's MPG possibilities.

I'll get a ring set, bearings too.

I have a standard flywheel to replace the prior cracked one, nothing fancy. The billet will come in when the turbo setup comes through.

Oblio #48046 02/21/09 06:41 PM
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 Originally Posted By: Oblio
Neonova75,

How much boost do you plan on running? I'm in the same boat you are and I've read and heard it said by many that a stock 250 will easily handle up to 7 pounds boost, which is what I'm running.

Oblio


Well I have a few tuner friends helping me out (big into toyota's and subaru's lol) and they want me to install a boost gauge, so I can adjust 8lbs city driving, and kick it up to 15 on the highway.

I read some brazilian sixes are handling insane amounts of boost, 20-30 with stock cranks.

neonova75 #48052 02/22/09 03:01 AM
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Guys in Brazil are boosting 30-40 PSI.

Install forged pistons.

Side grind,polish & shot peen your rods along with resizing & ARP rod bolts.
Knife edging the crank is a waste of $$$$, unless you are spinning some high RPMs & are looking for every last bit of HP.

Cylinder head, Twisted6 AKA Larry is in Florida for your head needs.

You do not want to use any forged cranks form GM stock.
They have less counter weights,vibrate more & often crack more so over stanadard cast cranks.

If you have any chemical places out there that will chemically dip your block & remove all the rust,better choice plus less time,& removes all rust. Cost is about $60-$100 range possibly?


MBHD


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Thanks for the heads up on the forged crank. I am pretty sure the stock one will do fine for what I want to run, it's pretty sturdy.

I'd really like to dip that block, but unless a miracle comes along for an extra 100 bucks, i can't afford it. I figure the CLR remover I got will be the best I can do for now. The radiator definitely needs to be dipped though.

What kind of fuel setup would work best for a t4 turbo? I'm thinking about an electrical fuel pump, but IDK how well that would be, and I hear you can get more "uumph" from a carb'ed setup over a FI setup.

neonova75 #48091 02/24/09 02:01 AM
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F.I. is the way to go.

Not sure of what your plans are on turbocharging?
Draw through,blow through? You want to run a carb?
How much power do you want to make?

MBHD


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I can rarely post on here for some reason.

But anyway, I'd like to run carb'ed but I will probably run the cheapest setup at first, till everything seems to be in order (since carb would be fastest) then do more research and see if FI is worth the money for what I want to accomplish.

My goal is to get 350 hp to the ground, 350 tq, and maintain 22+ mpg.


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