lt1 block questions.
#1
lt1 block questions.
This is my first f body and I pulled the motor from my 96 camaro that has about 110k miles on it. Was told it had a blown head gasket and sat for about 7 months. I'm looking at taking it to the machine shop to get some work done on the block. I was advised to take it in and get new bearings and o rings, get it honed, and arp 2000 bolts. I called up a local shop and they said with that many miles it'll have to be bored 30 over cause there is most likely a lip in the cylinders (which there is). I'm not really looking to bore it at the moment unless I really need to, id rather put it else where but will do what I gotta do to get it running good. I don't know to much about the blocks, but if I have to get it bored, what should I do for pistons and the other components? Also, does a 350 bored 30 over make a 355?
#2
TECH Senior Member
iTrader: (2)
If the cylinders are that out of round then yes you'll need it to be bored to clean it up. You don't necessarily need a .030", you may be able to get away with a .020", but that won't matter too much.
You'll need oversized pistons also. There are several companies who offer a nice budget hypereutectic piston. A 350 .030" is a 355.
You'll need oversized pistons also. There are several companies who offer a nice budget hypereutectic piston. A 350 .030" is a 355.
#3
Village Troll
iTrader: (2)
The machine shop can measure the bores to see if they're still true as well as making sure the cross hatch is still in tact and that there aren't any vertical marks in the bores that may hinder the sealing of the rings. If that all checks out then there's no reason why you can't reuse the stock rods/pistons as long as you use them in the same bores they came out of.
If you do have to bore it, it depends on what you want to do. If you are staying N/A then you can stay with a .030 over stock replacement hyper-u and be fine. You can also do rod bolts, but it would be highly recommended you get the rods redone. Again, I wouldn't do bolts unless you are doing to go over 6500rpm. JMO.
I had a stock rebuild done on an engine with approx 100K on it and the bores checked out great and the stock rods/pistons were reused. You may be able to do so as well.
If you do have to bore it, it depends on what you want to do. If you are staying N/A then you can stay with a .030 over stock replacement hyper-u and be fine. You can also do rod bolts, but it would be highly recommended you get the rods redone. Again, I wouldn't do bolts unless you are doing to go over 6500rpm. JMO.
I had a stock rebuild done on an engine with approx 100K on it and the bores checked out great and the stock rods/pistons were reused. You may be able to do so as well.
#5
Thanks for the replies, I really appreciate it. I also think some of these shops are just trying to make money off of me since I am new at this. Some of the cross hatch is starting to go and I believe also that it is carbon. When I called them up they also said if I do rod bolts then to get the rods redone as well. I have another 350 sitting in my garage that I was going to build into a 355 so I can still drive with this one in the meantime. Ill give a few places a call and see what they say.
#6
Al 95 Z28 going back together slowly.
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#11
Yeah I figured id just get it rebuilt just so it lasts a lot longer as well. And sorry, I didn't know they come with them, all this is new to me, just trying to build knowledge! I got mr. Gaskets head gaskets a few weeks back because I thought that was all I was going to have done to it. Now that I'm boring it, do I need different head gaskets?
#12
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Yeah I figured id just get it rebuilt just so it lasts a lot longer as well. And sorry, I didn't know they come with them, all this is new to me, just trying to build knowledge! I got mr. Gaskets head gaskets a few weeks back because I thought that was all I was going to have done to it. Now that I'm boring it, do I need different head gaskets?
Some numbers you will need to know are: Bore 4.030, stroke 3.46, head CC ~55cc, deck clearance is how far you piston sits in the hole.. typically .020-.025.
#13
I have mr. Gaskets 5716g (.026 thickess) gaskets. Was wondering if they'd still work with it now being bored 30 over. But I found the answer to my question. Is there anything else recommended that I should have done while its out?
#17
I am wanting to aim for a CR of 11:1. I am trying to play with some numbers with a chart I got, I do not know what the top ring down is, or what dome or dish is..I talked to a machine shop and they said anything over 10.5 is useless on pump gas, which i can tell isn't true. But, I am trying to figure out how much I need to get milled from my heads to reach that.