Which Block for an 85 C4?
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
Which Block for an 85 C4?
Ok, I want to buy a 350 block and build it into a 383. What exactly do I need to be looking for in a block for it to go right in without any problems? Thanks, Zak.
Pro
Joined: Nov 2006
Posts: 638
Likes: 0
From: Plano TX
I think you need to probably provide more information before this can be answered. If you're going to stick to the TPI or one of the intake variants based on this, any Gen 1 block would be fine. I'd personally go for a roller block in that case.
Race Director
Joined: Feb 2004
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Oil pan and dipstick must match the year of the block, and fit the chassis.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
Pro
Joined: Nov 2006
Posts: 638
Likes: 0
From: Plano TX
Here's another suggestion, just based on reading other posts of yours... unless you're wanting to rebuild the motor as a hobby and to learn -- which is always fun -- I would probably just sell it and get another Vette that's running good. They're cheap enough here in the Dallas area. Going the route you're speaking can get really expensive really fast. Then again, like I said, if it's a hobby thing and you want to do it to learn, there's nothing building your own motor and firing it up for the first time.
Not to mention all the new random tools you get to buy. That's always fun too! You get some really cool niche tools when doing this stuff.
If you're wanting to rebuild it cause you think it's just not running right, do some diagnostics. You might shocked by what you find. It could be something like a bad MAF or some other sensor causing all of your issues. A good compression and leak down test can tell you a lot about your engine. The FSM also carries good troubleshooting information too.
Not to mention all the new random tools you get to buy. That's always fun too! You get some really cool niche tools when doing this stuff.
If you're wanting to rebuild it cause you think it's just not running right, do some diagnostics. You might shocked by what you find. It could be something like a bad MAF or some other sensor causing all of your issues. A good compression and leak down test can tell you a lot about your engine. The FSM also carries good troubleshooting information too.
Last edited by evmlarry; Nov 24, 2007 at 11:01 AM.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
Here's another suggestion, just based on reading other posts of yours... unless you're wanting to rebuild the motor as a hobby and to learn -- which is always fun -- I would probably just sell it and get another Vette that's running good. They're cheap enough here in the Dallas area. Going the route you're speaking can get really expensive really fast. Then again, like I said, if it's a hobby thing and you want to do it to learn, there's nothing building your own motor and firing it up for the first time.
Not to mention all the new random tools you get to buy. That's always fun too! You get some really cool niche tools when doing this stuff.
If you're wanting to rebuild it cause you think it's just not running right, do some diagnostics. You might shocked by what you find. It could be something like a bad MAF or some other sensor causing all of your issues. A good compression and leak down test can tell you a lot about your engine. The FSM also carries good troubleshooting information too.
Not to mention all the new random tools you get to buy. That's always fun too! You get some really cool niche tools when doing this stuff.
If you're wanting to rebuild it cause you think it's just not running right, do some diagnostics. You might shocked by what you find. It could be something like a bad MAF or some other sensor causing all of your issues. A good compression and leak down test can tell you a lot about your engine. The FSM also carries good troubleshooting information too.
Yeah, well Ive always wanted to learn to do this anyway.
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Team Owner
Joined: Feb 2006
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From: sw Ohio
If your looking to go carb, its actually rather inexpensive to do. The parts to do the conversion will cost around $600. Granted there are drawbacks when compared to the stock TPI and of course it will no longer be original.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
There is some good information her on carb conversions with C4's. Do a search using strings like "carb conversion" or "carburetor".
If you have to go thru emissions testing, the carb setup will mostl likely fail and it there is a visual inspection, well..... And you have to be careful about hood clearance.
Buying an old "seasoned" block may work, but you really need to sit down and figure out what you will need in terms of parts and labor to build a motor. You have to find a reputable machine shop to do the necessary crank and block work, cylinder head work and possibly basic assembly. You will be buying new pistons, rings, bearings, gasket sets, a carb, possibly new rods, cam, valvetrain pieces, water pump, bracketry for accesories, etc. The cost of all of this adds up fast!
Factor in all of that work and cost and compare that to available crate motors. A GM ZZ4 motor is a little over $3100 and it comes with a warranty, something that a machine shop probably will not give you. Jasper has a line of performance motors and they offer a great warranty. Both GM and Jasper also have 383-inch motors.
If you have to go thru emissions testing, the carb setup will mostl likely fail and it there is a visual inspection, well..... And you have to be careful about hood clearance.
Buying an old "seasoned" block may work, but you really need to sit down and figure out what you will need in terms of parts and labor to build a motor. You have to find a reputable machine shop to do the necessary crank and block work, cylinder head work and possibly basic assembly. You will be buying new pistons, rings, bearings, gasket sets, a carb, possibly new rods, cam, valvetrain pieces, water pump, bracketry for accesories, etc. The cost of all of this adds up fast!
Factor in all of that work and cost and compare that to available crate motors. A GM ZZ4 motor is a little over $3100 and it comes with a warranty, something that a machine shop probably will not give you. Jasper has a line of performance motors and they offer a great warranty. Both GM and Jasper also have 383-inch motors.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
There is some good information her on carb conversions with C4's. Do a search using strings like "carb conversion" or "carburetor".
If you have to go thru emissions testing, the carb setup will mostl likely fail and it there is a visual inspection, well..... And you have to be careful about hood clearance.
Buying an old "seasoned" block may work, but you really need to sit down and figure out what you will need in terms of parts and labor to build a motor. You have to find a reputable machine shop to do the necessary crank and block work, cylinder head work and possibly basic assembly. You will be buying new pistons, rings, bearings, gasket sets, a carb, possibly new rods, cam, valvetrain pieces, water pump, bracketry for accesories, etc. The cost of all of this adds up fast!
Factor in all of that work and cost and compare that to available crate motors. A GM ZZ4 motor is a little over $3100 and it comes with a warranty, something that a machine shop probably will not give you. Jasper has a line of performance motors and they offer a great warranty. Both GM and Jasper also have 383-inch motors.
If you have to go thru emissions testing, the carb setup will mostl likely fail and it there is a visual inspection, well..... And you have to be careful about hood clearance.
Buying an old "seasoned" block may work, but you really need to sit down and figure out what you will need in terms of parts and labor to build a motor. You have to find a reputable machine shop to do the necessary crank and block work, cylinder head work and possibly basic assembly. You will be buying new pistons, rings, bearings, gasket sets, a carb, possibly new rods, cam, valvetrain pieces, water pump, bracketry for accesories, etc. The cost of all of this adds up fast!
Factor in all of that work and cost and compare that to available crate motors. A GM ZZ4 motor is a little over $3100 and it comes with a warranty, something that a machine shop probably will not give you. Jasper has a line of performance motors and they offer a great warranty. Both GM and Jasper also have 383-inch motors.
Yeah, I will probably just put the TPI on it for now.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
Ok, thanks. Ive been checking Craigslist and I found a 350 that Im looking at getting. Heres the ad.
Chevy 4-bolt 350 block, crank, cam, rods, pistons. - $150
"Up for sale I have a Chevy 2-piece rear 4-bolt block. Block does not appear to have been bored yet. Also will include stock crank, stock cam, rods and pistons, flywheel, crank pulley, misc bolts, 2 motor mount plates, other misc related parts. No heads, engine is disassembled, from a project that never left the ground. Good for rebuild into 383CI stroker."
Does this sound like a good deal?
Team Owner
Joined: Dec 1999
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
One of the problems in buying used parts is that you really cannot tell their condition. There could be very small cracks in the crank that are not readily visible to the naked eye, and the same with the block, rods and pistons.
The crank journals may be already turned down to where you cannot get decent oversized bearings, same with the rods and I would not even trust used pistons.
Without checking all of the parts using something like magnaflux testing, there is no way to know if any pieces are even useable.
And I certainly would not buy a short block without a visual inspection. Even with being able to see it first, I would want to have the components checked by a machine shop as a condition of the sale. You could offer to pay for a shop to inspect the stuff and then work out a deal if everything is suitable for machine work and to handle whatever HP/torque uptput you are going for.
I just wouldn't accept the seller's claims until I had a chance to see and inspect the pieces.
The crank journals may be already turned down to where you cannot get decent oversized bearings, same with the rods and I would not even trust used pistons.
Without checking all of the parts using something like magnaflux testing, there is no way to know if any pieces are even useable.
And I certainly would not buy a short block without a visual inspection. Even with being able to see it first, I would want to have the components checked by a machine shop as a condition of the sale. You could offer to pay for a shop to inspect the stuff and then work out a deal if everything is suitable for machine work and to handle whatever HP/torque uptput you are going for.
I just wouldn't accept the seller's claims until I had a chance to see and inspect the pieces.
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
One of the problems in buying used parts is that you really cannot tell their condition. There could be very small cracks in the crank that are not readily visible to the naked eye, and the same with the block, rods and pistons.
The crank journals may be already turned down to where you cannot get decent oversized bearings, same with the rods and I would not even trust used pistons.
Without checking all of the parts using something like magnaflux testing, there is no way to know if any pieces are even useable.
And I certainly would not buy a short block without a visual inspection. Even with being able to see it first, I would want to have the components checked by a machine shop as a condition of the sale. You could offer to pay for a shop to inspect the stuff and then work out a deal if everything is suitable for machine work and to handle whatever HP/torque uptput you are going for.
I just wouldn't accept the seller's claims until I had a chance to see and inspect the pieces.
The crank journals may be already turned down to where you cannot get decent oversized bearings, same with the rods and I would not even trust used pistons.
Without checking all of the parts using something like magnaflux testing, there is no way to know if any pieces are even useable.
And I certainly would not buy a short block without a visual inspection. Even with being able to see it first, I would want to have the components checked by a machine shop as a condition of the sale. You could offer to pay for a shop to inspect the stuff and then work out a deal if everything is suitable for machine work and to handle whatever HP/torque uptput you are going for.
I just wouldn't accept the seller's claims until I had a chance to see and inspect the pieces.
Well with what I want to do, I would be replacing all of these parts anyway. I really only need the block.
Team Owner
Joined: Dec 1999
Posts: 34,873
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
A seasoned block is always a good starting point for a build-up, but you still should have the block magnafluxed and dye-checked to make sure there are no cracks in the cylinder walls, lifter bores, or even around the mains.
Team Owner
Joined: May 2002
Posts: 24,337
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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
I would get a 4-bolt roller, I know these were used in the trucks around 96-98, which there are a bazillion of, not sure about other applications.
This link may be useful:
http://forums.corvetteforum.com/showthread.php?t=496402
This link may be useful:
http://forums.corvetteforum.com/showthread.php?t=496402
Thread Starter
Instructor
Joined: Sep 2007
Posts: 175
Likes: 1
From: Fort Worth Texas
Yeah, I will definitely do that. Will any 2 piece rear main seal 4 bolt main 350 block work with everything currently in my 85? Thanks, Zak.
Burning Brakes
Joined: Feb 2001
Posts: 769
Likes: 0
From: Granbury TX
As mentioned in an earlier post in your string, the only difference in pre 86 blocks may be the side the dipstick is on. This of course requires the matching oil pan. If the block you are buying has the dipstick on the same side as your 85, you won't know the differance from it and rebuilding your original block. Some are 2 bolt and some are 4 bolt, Other than that, most will slip right into your 85 just fine. There were some variations in metalurgy over the years and I've heard of some crappy castings made in Mexico ( that may be bullsht). I used a 79 400 cid block in my 87. The 400 block has differant coolant holes for the head and larger mains, but after assembly, all the factory accessories fit perfectly and the installation went off without a hitch.
Instructor
Joined: Nov 2006
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From: Detroit
1986 I believe they changed to 1 piece rear main seal to prevent leaks, I am not sure if the crankshaft changed when this did. Speaking from experience the easiest and least aggravating way to do this is to buy an crate engine short block or long block from GM or someone else. Everything is already sorted out and you know what the power is and you usually get a warranty. GM's 383s are prettty and nice and cheap also I would check out summit racing or jegs to get an idea what is out there.