Rebuilding the 350.. again
02-04-2012, 11:01 AM
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Car: 88 trans am
Engine: 350sb
Transmission: t400
Axle/Gears: 7.5/2.73
Rebuilding the 350.. again
So.. I blew up my trans am again for the 2nd time. I started off with a 305 TPI, swapped it for a 350sbc, now I blew up the 350.
Now for the rebuild notes and progress. Currently I have already taken the motor out and ripped it down to the bare block. In this I found that I spun every single bearing, all my rods are screwed, my crank got beat up by my rods, and my heads might have valve damage. This is only the start of my problems most likely, as there is probably a lot more damage then I know of. So, here are some pictures and then I will continue with the boring typing part.
So this is where I started.
Break it down a little.
And detach the headers.
Give her the 1, 2 , lift
And then you have this
Now for the rebuild notes and progress. Currently I have already taken the motor out and ripped it down to the bare block. In this I found that I spun every single bearing, all my rods are screwed, my crank got beat up by my rods, and my heads might have valve damage. This is only the start of my problems most likely, as there is probably a lot more damage then I know of. So, here are some pictures and then I will continue with the boring typing part.
So this is where I started.
Break it down a little.
And detach the headers.
Give her the 1, 2 , lift
And then you have this
Last edited by thebuffalo; 02-17-2012 at 11:59 AM.
02-04-2012, 11:02 AM
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Car: 88 trans am
Engine: 350sb
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Re: Rebuilding the 350.. again
So now you have to take it apart and see what all is broken. In my case, pretty much everything.
so I have a starter..
A set of lifters I'm probably going to replace, even though they all look brand new.
My distributor, fuel pump, lifters, and my broken oil pump. I know the oil pump is bad because my bearings spun and produced metal shards that clogged it.
My heads and beast of a cam, .488 lift. and the edelbrock performer intake.
My BECOOL Radiator and trans-cooler.
Rocker arms with +100 push rods
Edelbrock 750cfm carb w/ shiny alternator.
Timing chain/gear, harmonic balancer, oil pump housing and a bunch of destroyed bearings.
so I have a starter..
A set of lifters I'm probably going to replace, even though they all look brand new.
My distributor, fuel pump, lifters, and my broken oil pump. I know the oil pump is bad because my bearings spun and produced metal shards that clogged it.
My heads and beast of a cam, .488 lift. and the edelbrock performer intake.
My BECOOL Radiator and trans-cooler.
Rocker arms with +100 push rods
Edelbrock 750cfm carb w/ shiny alternator.
Timing chain/gear, harmonic balancer, oil pump housing and a bunch of destroyed bearings.
Last edited by thebuffalo; 02-04-2012 at 11:10 AM.
02-04-2012, 11:10 AM
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Car: 88 trans am
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Re: Rebuilding the 350.. again
168 tooth flexplate, WHY FLEXPLATE YOU ASK? Because I have a t400 semi-automatic transmission.
A broken crankshaft. stock.
A bunch of good pistons on a bunch of bad rods.
And the 350 4 bolt main, ready to be removed of its ugly paint and repainted.
Along with all parts being cleaned, and ready to be re-used. Atleast the ones I am re-using. More to come as soon as I get these parts in.
And this is a terrible work space.
Another Head shot.
Last edited by thebuffalo; 02-04-2012 at 11:21 AM.
02-04-2012, 11:10 AM
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Re: Rebuilding the 350.. again
It will if it's built for it.
Sounds like something was done seriously wrong when it was built. Did you check clearances?
02-04-2012, 11:20 AM
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Re: Rebuilding the 350.. again
Well, by punching it, I mean you probably shouldnt be doing track launches on a fresh rebuild thats planned to be a DD. And it for sure wasnt built for 6500 rpms lol. As far as the clearances, I'm pretty sure everything was right. But, I didn't put the internals together. I know that I was driving across a bridge and pop. But this time i will be doing everything and im going to make sure its right.
This is what I will be using to rebuild her, for reference
This is what I will be using to rebuild her, for reference
Last edited by thebuffalo; 02-04-2012 at 11:38 AM.
02-07-2012, 09:15 AM
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Re: Rebuilding the 350.. again
So right now I'm having trouble finding the right parts I need for the right price..
Does anyone know where I can get a kit of all the gaskets, main bearing/rod bearings, rings/pistons, rods, oil pump, & crank? Preferably $600 or less? Thanks in advance.
Summit seems to be slacking
Does anyone know where I can get a kit of all the gaskets, main bearing/rod bearings, rings/pistons, rods, oil pump, & crank? Preferably $600 or less? Thanks in advance.
Summit seems to be slacking
02-07-2012, 06:24 PM
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Re: Rebuilding the 350.. again
I've had good luck with Northern Auto Parts,they will tailor an engine "kit" to your needs.
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02-07-2012, 07:59 PM
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Re: Rebuilding the 350.. again
600 gonna be tight with needing a crank and rods. More likely between 600-1,000. Watch what you cut costs on. Get a better balancer if you want those high rpms. And have block line bored and crank balanced also. What HP are you trying to achieve?
02-09-2012, 09:17 AM
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Car: 88 trans am
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Re: Rebuilding the 350.. again
I got everything I need for $612!! but I didn't get a kit.
I'm going for around 400rwhp max. And by block line bored do you mean getting the block bored? right now its stock 4.000" and the stroke is stock 3.48". I already got 4" pistons :\
And crank balanced?Not sure what this means, I'm no professional
I'm going for around 400rwhp max. And by block line bored do you mean getting the block bored? right now its stock 4.000" and the stroke is stock 3.48". I already got 4" pistons :\
And crank balanced?Not sure what this means, I'm no professional
02-09-2012, 09:49 AM
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Car: 89' camaro RS TTOP
Engine: 92 5.0tpi Bosch III, headers, msd
Transmission: 700r4 built. trans go. 2,300 stall
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Re: Rebuilding the 350.. again
Line boring deals with crank journals. A must for high rpm engines. Guarantees the journals are true and straight. How do you know your stock bores are in good shape? Mine looked good but were out of round. Had to be bored out. A good quality crank will come balanced in most situations. A balanced crank is also a must for high rpm engines. Hate to see all this work you're doing not last. Replace Cam bearings also. But if you don't have a Cam bearing install tool, take to a machine shop. Cost me 30 bucks to have done. And most importantly, take your time. Seriously.
02-09-2012, 10:04 AM
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Re: Rebuilding the 350.. again
I did get cam bearings, As far as the crank, i just bought a Eagle Cast Steel Crankshaft. How can I find out if my stock bore is okay? I'm not sure if the crank comes balanced. As for getting cam bearings installed do I bring the cam and bearings or the block? I'm pretty sure my old cam bearings are still stuck in the block.
Do I just need to bring my block & heads to a machine shop and get them looked at?
Do I just need to bring my block & heads to a machine shop and get them looked at?
02-09-2012, 10:32 AM
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Re: Rebuilding the 350.. again
Definitely throw block in car and take to machine shop. Most will inspect for free it dirt cheap. Cam bearings go in block. Takes a special tool to install and remove. If bores are good, just have them honed. If not go minimum over to make bore true and exchange your pistons for correct oversize. Machine shop will have to rehang your rods on the new pistons also. Stock rods use a press in wrist pin. If you have money, you can get new rods and pistons that use a floating wrist pin. Cost me I beloved 25 to have rods rehung on my new pistons. I went. 030" over on my bore.
02-09-2012, 10:38 AM
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Re: Rebuilding the 350.. again
I did get floating rods! Just incase I needed to change pistons alot hahaha. So I guess I will be taking the block to a machine shop whenever I get a open day. Now I just have to find a good one around here.
02-13-2012, 01:26 PM
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Re: Rebuilding the 350.. again
Parts just came in, before I get to installing I want to get a few things checked out. I need to get my cylinder walls honed out im assuming, my heads checked to be sure theyre good, my camshaft bearings are stuck in the block and I have to get the new ones put on, and my pistons i got I dont have the necessary tools to remove the pin, and i don't want to attempt to do it and crack my piston. What else should I have done at the machine shop?
02-13-2012, 05:56 PM
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Unless the pistons are oversized from your current bore size, the cylinders won't have to be honed, just a glaze break for the new rings to break in.
The machine shop should do the cam bearing install. If you have floating pins, you should be able to install the pistons, but you may want to go ahead and have the shop do it to reduce the chance of improper installation.
The machine shop should do the cam bearing install. If you have floating pins, you should be able to install the pistons, but you may want to go ahead and have the shop do it to reduce the chance of improper installation.
02-13-2012, 05:58 PM
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Re: Rebuilding the 350.. again
Unless the pistons are oversized from your current bore size, the cylinders won't have to be honed, just a glaze break for the new rings to break in.
The machine shop should do the cam bearing install. If you have floating pins, you should be able to install the pistons, but you may want to go ahead and have the shop do it to reduce the chance of improper installation.
The machine shop should do the cam bearing install. If you have floating pins, you should be able to install the pistons, but you may want to go ahead and have the shop do it to reduce the chance of improper installation.
02-13-2012, 10:28 PM
#18
Re: Rebuilding the 350.. again
Depends.
Do you know how to fit rings to pistons/bores?
I also take issue with your "dont punch it" blanket statement. How do you think top level drag cars break in their engines? You think they street drive them for 500 miles? They throw em and beat the snot out of em. 500 miles of easy driving wouldn't make a difference. If the bottom end was gonna let go when you went WOT, it was gonna do it regardless of whether or not you babied it for a year or you broke it in like you were trying to blow it up.
Also, you can turn down cranks that are damaged. Why did you buy a new one? Is the old one broken?
Do you know how to fit rings to pistons/bores?
I also take issue with your "dont punch it" blanket statement. How do you think top level drag cars break in their engines? You think they street drive them for 500 miles? They throw em and beat the snot out of em. 500 miles of easy driving wouldn't make a difference. If the bottom end was gonna let go when you went WOT, it was gonna do it regardless of whether or not you babied it for a year or you broke it in like you were trying to blow it up.
Also, you can turn down cranks that are damaged. Why did you buy a new one? Is the old one broken?
02-14-2012, 11:55 AM
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Re: Rebuilding the 350.. again
Depends.
Do you know how to fit rings to pistons/bores?
I also take issue with your "dont punch it" blanket statement. How do you think top level drag cars break in their engines? You think they street drive them for 500 miles? They throw em and beat the snot out of em. 500 miles of easy driving wouldn't make a difference. If the bottom end was gonna let go when you went WOT, it was gonna do it regardless of whether or not you babied it for a year or you broke it in like you were trying to blow it up.
Also, you can turn down cranks that are damaged. Why did you buy a new one? Is the old one broken?
Do you know how to fit rings to pistons/bores?
I also take issue with your "dont punch it" blanket statement. How do you think top level drag cars break in their engines? You think they street drive them for 500 miles? They throw em and beat the snot out of em. 500 miles of easy driving wouldn't make a difference. If the bottom end was gonna let go when you went WOT, it was gonna do it regardless of whether or not you babied it for a year or you broke it in like you were trying to blow it up.
Also, you can turn down cranks that are damaged. Why did you buy a new one? Is the old one broken?
But, I dropped my block and heads off at the machine shop to get checked out, turns out my block was bored .030 over and my cylinder walls have some decent damage. So, I'm getting it bored another .030 over to make it .060 and I'm returning my 4.000" pistons and ring set in for a 4.060" set. Getting the block cleaned and all that good stuff too. Next step will be painting all the stuff that needs painting, cleaning all my bolts and random parts, then the fun will begin.
Last edited by thebuffalo; 02-14-2012 at 11:58 AM.
02-14-2012, 01:55 PM
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Re: Rebuilding the 350.. again
for my budget 355 build i used the sealed power kit from summit, came with everything including pistons.. just need crank and rods for $290.. a crank from summit is only around $200 and a set of new rods would be around $200. but if you have std bearings you can use the summit rebuild kit for $210.. and be in your budget. this will be my second time using the kit and have great results with them, i am having a machine shop balance mine though.
good luck on your build!
good luck on your build!
02-14-2012, 01:57 PM
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Re: Rebuilding the 350.. again
for my budget 355 build i used the sealed power kit from summit, came with everything including pistons.. just need crank and rods for $290.. a crank from summit is only around $200 and a set of new rods would be around $200. but if you have std bearings you can use the summit rebuild kit for $210.. and be in your budget. this will be my second time using the kit and have great results with them, i am having a machine shop balance mine though.
good luck on your build!
good luck on your build!
I also got the casting number off the back of my 350
3970010, is this a good 350?
Last edited by thebuffalo; 02-14-2012 at 02:11 PM.
02-14-2012, 02:11 PM
#22
Re: Rebuilding the 350.. again
But, I dropped my block and heads off at the machine shop to get checked out, turns out my block was bored .030 over and my cylinder walls have some decent damage. So, I'm getting it bored another .030 over to make it .060 and I'm returning my 4.000" pistons and ring set in for a 4.060" set. Getting the block cleaned and all that good stuff too. Next step will be painting all the stuff that needs painting, cleaning all my bolts and random parts, then the fun will begin.
I had a .060 over block, my first 350, lasted me one time around the block before it started puking coolant into the oil through this crack:
Nice and steam cleaned.... had been running a total of 30 minutes at that point.
02-14-2012, 02:13 PM
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Re: Rebuilding the 350.. again
All the motors I have built for me or cars I build for people go right from assembly to the dyno. They have the cams broken in if needed then change the oil, bring motor to temp and we start flogging it on the dyno immediately. There is no break in on an engine. Set the timing correctly, figure out a/f ratio and let it eat.
02-14-2012, 02:13 PM
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Re: Rebuilding the 350.. again
Did they sonic check the bores before they bored it to .060? Are they sure it's safe?
I had a .060 over block, my first 350, lasted me one time around the block before it started puking coolant into the oil.
Nice and steam cleaned.... had been running a total of 30 minutes at that point.
I had a .060 over block, my first 350, lasted me one time around the block before it started puking coolant into the oil.
Nice and steam cleaned.... had been running a total of 30 minutes at that point.
02-14-2012, 02:25 PM
#25
Re: Rebuilding the 350.. again
Depends on the block man. The only way to know if your block can handle it is a sonic test.
I would find another block.
Some of this is drivel, but it's an interesting discussion:
http://www.hotrodders.com/forum/60-o...ch-4256-1.html
Like I said, mine was fine for the cam break in. I actually had to abort mid break in when I had an unrelated problem. 3 months and some new cylinder heads later, I finished the break in and the bore looked fine then. Changed the oil afterwards. Oil looked fine. Went around the block to start tweaking the TV cable to spec, and noticed a tapping valve, decided to go over the valve lash routine again and there was milky oil EVERYWHERE.
All it takes is one tiny spot in one cylinder to let go under pressure from the walls being too thin in just that one spot, and the block is pretty much a waste unless you're silly enough to sleeve it and hope the other bores aren't on the virge of breaking too.
And mine was one of those "magical" 010 blocks from the 60s too. No block is immune to production variances. If the walls are too thin and it doesnt spring a leak and crack like mine, you will still be more prone to ring sealing issues long term.
I have never heard of a 4.145 bore on a 350... thats more than a 400sb and their cylinder walls are siamesed.
Ive seen a lot of .060 over 350s work just fine. Mine didn't work fine.
Also, FYI, if you buy a brand new 350 block, their maximum bore is 4.030 according to GM. That's new production with modern machines and tolerances. I'd grudgingly push a good block to 4.040, but definitely no farther. Machinework is too expensive to waste it on a gamble like a .060 overbore in my opinion.
I would find another block.
Some of this is drivel, but it's an interesting discussion:
http://www.hotrodders.com/forum/60-o...ch-4256-1.html
Like I said, mine was fine for the cam break in. I actually had to abort mid break in when I had an unrelated problem. 3 months and some new cylinder heads later, I finished the break in and the bore looked fine then. Changed the oil afterwards. Oil looked fine. Went around the block to start tweaking the TV cable to spec, and noticed a tapping valve, decided to go over the valve lash routine again and there was milky oil EVERYWHERE.
All it takes is one tiny spot in one cylinder to let go under pressure from the walls being too thin in just that one spot, and the block is pretty much a waste unless you're silly enough to sleeve it and hope the other bores aren't on the virge of breaking too.
And mine was one of those "magical" 010 blocks from the 60s too. No block is immune to production variances. If the walls are too thin and it doesnt spring a leak and crack like mine, you will still be more prone to ring sealing issues long term.
I have never heard of a 4.145 bore on a 350... thats more than a 400sb and their cylinder walls are siamesed.
Ive seen a lot of .060 over 350s work just fine. Mine didn't work fine.
Also, FYI, if you buy a brand new 350 block, their maximum bore is 4.030 according to GM. That's new production with modern machines and tolerances. I'd grudgingly push a good block to 4.040, but definitely no farther. Machinework is too expensive to waste it on a gamble like a .060 overbore in my opinion.
Last edited by InfernalVortex; 02-14-2012 at 02:32 PM.
02-14-2012, 02:37 PM
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Re: Rebuilding the 350.. again
Depends on the block man. The only way to know if your block can handle it is a sonic test.
I would find another block.
Some of this is drivel, but it's an interesting discussion:
http://www.hotrodders.com/forum/60-o...ch-4256-1.html
Like I said, mine was fine for the cam break in. I actually had to abort mid break in when I had an unrelated problem. 3 months and some new cylinder heads later, I finished the break in and the bore looked fine then. Changed the oil afterwards. Oil looked fine. Went around the block to start tweaking the TV cable to spec, and noticed a tapping valve, decided to go over the valve lash routine again and there was milky oil EVERYWHERE.
All it takes is one tiny spot in one cylinder to let go under pressure from the walls being too thin in just that one spot, and the block is pretty much a waste unless you're silly enough to sleeve it and hope the other bores aren't on the virge of breaking too.
And mine was one of those "magical" 010 blocks from the 60s too. No block is immune to production variances. If the walls are too thin and it doesnt spring a leak and crack like mine, you will still be more prone to ring sealing issues long term.
I have never heard of a 4.145 bore on a 350... thats more than a 400sb and their cylinder walls are siamesed.
Ive seen a lot of .060 over 350s work just fine. Mine didn't work fine.
Also, FYI, if you buy a brand new 350 block, their maximum bore is 4.030 according to GM. That's new production with modern machines and tolerances. I'd grudgingly push a good block to 4.040, but definitely no farther. Machinework is too expensive to waste it on a gamble like a .060 overbore in my opinion.
I would find another block.
Some of this is drivel, but it's an interesting discussion:
http://www.hotrodders.com/forum/60-o...ch-4256-1.html
Like I said, mine was fine for the cam break in. I actually had to abort mid break in when I had an unrelated problem. 3 months and some new cylinder heads later, I finished the break in and the bore looked fine then. Changed the oil afterwards. Oil looked fine. Went around the block to start tweaking the TV cable to spec, and noticed a tapping valve, decided to go over the valve lash routine again and there was milky oil EVERYWHERE.
All it takes is one tiny spot in one cylinder to let go under pressure from the walls being too thin in just that one spot, and the block is pretty much a waste unless you're silly enough to sleeve it and hope the other bores aren't on the virge of breaking too.
And mine was one of those "magical" 010 blocks from the 60s too. No block is immune to production variances. If the walls are too thin and it doesnt spring a leak and crack like mine, you will still be more prone to ring sealing issues long term.
I have never heard of a 4.145 bore on a 350... thats more than a 400sb and their cylinder walls are siamesed.
Ive seen a lot of .060 over 350s work just fine. Mine didn't work fine.
Also, FYI, if you buy a brand new 350 block, their maximum bore is 4.030 according to GM. That's new production with modern machines and tolerances. I'd grudgingly push a good block to 4.040, but definitely no farther. Machinework is too expensive to waste it on a gamble like a .060 overbore in my opinion.
I talked to the guy at the machine shop, He said that my block will be fine with 4.060" bore. He says that this block is a heavy duty block and I could go to 4.080" but he doesn't recommend any more than that. But this got me thinking, if my block is at 4.030" right now, Why were my old pistons GM pistons with stock numbers? Is it possible my 350 was factory 4.030"? Is there any way of finding out if they had a special package that might have had the oversized bore?
Last edited by thebuffalo; 02-14-2012 at 02:49 PM.
02-14-2012, 03:02 PM
#27
Re: Rebuilding the 350.. again
I think usually you're fine, but it's roulette. I'd probably run it and see what happens at this point if you're already this deep in it. Just be ready to source another block if you need to. There's no such thing as a "heavy duty block" really, unless you get a bowtie block or something like that. Aftermarket or high end GM blocks like that cost serious money, though. A Dart (which can be had in a 400 bore for the same price) SHP block is $1500 before machinework. Not bad for what you get, but it's definitely not cheap. And to be fair, any used block is a risk. You just never know. Some blocks .030 is too far. Some can go .060 and be perfectly fine. Just depends.
02-14-2012, 03:04 PM
#28
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Re: Rebuilding the 350.. again
Yeah, I paid $100 for this one when i got it. So hopefully I can find another one that cheap if things go sour
02-15-2012, 10:38 AM
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Re: Rebuilding the 350.. again
As soon as I actually start building the motor I will be taking more pics of every step and documenting pretty much everything.
02-17-2012, 08:34 AM
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Re: Rebuilding the 350.. again
Talked to the machine shop today, the hot tank had diesel parts in it all week so my block gets the weekend treatment. They're definately slowing me down 
Either or, pistons n rings got here
Either or, pistons n rings got here
02-17-2012, 09:00 AM
#34
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Re: Rebuilding the 350.. again
I still have a little over a 1/4" of wall thickness. I won't be boring it again. I actually thought it was stock 4.000" until I brought it there.
02-17-2012, 09:02 AM
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Re: Rebuilding the 350.. again
You didn't even have that much thickness when it was new.
02-17-2012, 09:08 AM
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Re: Rebuilding the 350.. again
I'm going by what the guy at the machine shop said
for what I know, if the block is bottom-side up, the ends of the cylinder walls do actually get very thin near where the crank goes, I have a pic of the cylinder wall, I'll upload it and circle where I'm talking about. When I say thin, I mean like.... really thin.
Right there, if the block was upside down you could see a thin piece where the cylinder wall extended past the solid part of the block and was about this thin --> ||
I'll try to find a better pic to better explain. Lol I just realized that this pic it kinda looks like im talking about the surface that connects to the head, but I'm talking about the bottom end by the crank
for what I know, if the block is bottom-side up, the ends of the cylinder walls do actually get very thin near where the crank goes, I have a pic of the cylinder wall, I'll upload it and circle where I'm talking about. When I say thin, I mean like.... really thin.
Right there, if the block was upside down you could see a thin piece where the cylinder wall extended past the solid part of the block and was about this thin --> ||
I'll try to find a better pic to better explain. Lol I just realized that this pic it kinda looks like im talking about the surface that connects to the head, but I'm talking about the bottom end by the crank
Last edited by thebuffalo; 02-17-2012 at 09:13 AM.
02-17-2012, 09:18 AM
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Re: Rebuilding the 350.. again
That's immaterial. Cylinder wall thickness is how thick the walls are in the unsupported region between the deck and the webbing.
02-17-2012, 09:32 AM
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Re: Rebuilding the 350.. again
I'm not too sure what 'webbing' is.. never heard this term before
02-17-2012, 09:41 AM
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Re: Rebuilding the 350.. again
It's the thickness "in the middle" that matters then, not at the ends.
02-17-2012, 09:47 AM
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Re: Rebuilding the 350.. again
So the thickness in between each cylinder? I don't know how this machine shop is with the whole honesty thing, I've never been to it before. But the guy I was talking to said if he ran into anything that made him think the block wouldn't be usable he would stop with what they're doing and call me and see what I wanted to do from there.
02-17-2012, 10:03 AM
#41
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Re: Rebuilding the 350.. again
The cylinder is a sleeve of metal attached to the block at the top of the bottom, and surrounded on all sides by coolant. The thickness is how much metal there is between the inside surface and the coolant.
By design there's nominally about .200" of wall in all directions on a new block, but the cores shift in all directions in the foundary so the I.D. and O.D. aren't concentric, and when the block is machined there'll be more or less thickness on some sides or all around.
On a good street block there should be at least .160" or .170" on the thrust side and at least .120" or .130" on the non-thrust side. A little bit less on the thrust side is ok if the cylinder is more concentric and the non-thrust side is thicker. The pin side is less important, about .100" is fine there.
Starting with .200" on the walls on a concentric block, boring it out .060" brings the thickness down to .170". There's about .010" of core shift tolerated in the non-thrust direction then while still having decent thickness.
But you can see how boring any further than .060" makes the walls too thin. You can also see that if the core was shifted more than .010" in the non-thrust direction then even boring .060" is too far. Likewise though, you could have some core shift in the thrust direction, and be able to get a little more bore out of it.
By design there's nominally about .200" of wall in all directions on a new block, but the cores shift in all directions in the foundary so the I.D. and O.D. aren't concentric, and when the block is machined there'll be more or less thickness on some sides or all around.
On a good street block there should be at least .160" or .170" on the thrust side and at least .120" or .130" on the non-thrust side. A little bit less on the thrust side is ok if the cylinder is more concentric and the non-thrust side is thicker. The pin side is less important, about .100" is fine there.
Starting with .200" on the walls on a concentric block, boring it out .060" brings the thickness down to .170". There's about .010" of core shift tolerated in the non-thrust direction then while still having decent thickness.
But you can see how boring any further than .060" makes the walls too thin. You can also see that if the core was shifted more than .010" in the non-thrust direction then even boring .060" is too far. Likewise though, you could have some core shift in the thrust direction, and be able to get a little more bore out of it.
02-17-2012, 10:17 AM
#42
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Re: Rebuilding the 350.. again
Okay, I understand that mostly, if I read it about 5 more times I should get it 100%.
Basically, I need to worry about the thickness of the wall so the core, where the coolant is?, doesn't end up leaking into the cylinders? Which would be a cracked, useless block if it wasn't thick enough to handle the piston throw? If this is right, then the only thing I don't really understand is the non-thrust side, the thrust side is the side that the pistons run against and the non-thrust is the coolant side? Reading what I'm typing confuses me even more because how can there be 2 different measurements of 1 thickness? I must not be right about the thrust/non-thrust side. Is it 2 different diameters?
Basically, I need to worry about the thickness of the wall so the core, where the coolant is?, doesn't end up leaking into the cylinders? Which would be a cracked, useless block if it wasn't thick enough to handle the piston throw? If this is right, then the only thing I don't really understand is the non-thrust side, the thrust side is the side that the pistons run against and the non-thrust is the coolant side? Reading what I'm typing confuses me even more because how can there be 2 different measurements of 1 thickness? I must not be right about the thrust/non-thrust side. Is it 2 different diameters?
Last edited by thebuffalo; 02-17-2012 at 10:33 AM.
02-17-2012, 10:32 AM
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Re: Rebuilding the 350.. again
The piston exerts more pressure on one side of the cylinder than the other due to the angle of the connecting rod. That's the thrust side. The other side is the non-thrust side.
On an SBC, that's the "lower" sides of the cylinders on the passenger side, and the "upper" sides of the cylinders on the drivers side.
On an SBC, that's the "lower" sides of the cylinders on the passenger side, and the "upper" sides of the cylinders on the drivers side.
02-17-2012, 10:37 AM
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Re: Rebuilding the 350.. again
Okay, That actually makes complete sense now. I'll talk to the guy at the machine shop and ask him to do measurements on that, I'm sure he probably already is but it's better to be safe than sorry.
02-22-2012, 10:04 AM
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Re: Rebuilding the 350.. again
Went to the machine shop yesterday to drop off cam bearings and freeze plugs. My block looks brand new, I'm already excited to get this thing running again. Should have it back in 3-4 business days so probably next Monday. Then all the fun begins.
02-22-2012, 01:44 PM
#46
Re: Rebuilding the 350.. again
350 with a hole in it:
Dont pay attention to the bottom, but the middle areas and how thin they look.
Here's an interesting post elsewhere on the interwebs.
http://speedtalk.com/forum/viewtopic...07a6af6a#p5832
http://speedtalk.com/forum/viewtopic.php?f=1&t=924 interesting thread
Dont pay attention to the bottom, but the middle areas and how thin they look.
Here's an interesting post elsewhere on the interwebs.
http://speedtalk.com/forum/viewtopic...07a6af6a#p5832
-here's some examples of cylinder wall thicknesses.
---------------------------------------
1-brand new 454 marine block, one of two in a twin engine Reggie Fountain 33 foot toy:
-thinnest thrust wall .215", thickest thrust wall .286", thinnest front or rear wall .105" thickest front or rear wall .255".
2-the other 454 block in the same boat:
-thinnest thrust wall .217", thickest thrust wall .273", thinnest front or rear wall .152", thickest front or rear wall .241"
---------------------------------------
3-another 454 passenger car block:
-thinnest thrust wall .293", thickest thrust wall .357", thinnest front or rear wall .131" thickest front or rear wall .305"
---------------------------------------
4-283 chevy bored out from 3.875" to 3.990" with the bores moved offcenter to save some of the wall thicknesses:
-thinnest thrust wall .135", thickest thrustwall .204", thinnest front or rear wall .103" thickest front or rear wall .216"
---------------------------------------
5-a 307 bored out from 3.875" to 3.930" with intentions of going to 4" and the bores centerlines were also moved to save wall thickness:
-thinnest thrust wall .209", thickest thrust wall .245", thinnest front or rear wall .113", thickest front or rear wall .209"
------------------------------------------
6-one 350 block I used for several years as a fairly serious oval track engine in the 1980's, about 500 honest HP:
-thinnest thrust wall .196", thickest thrust wall .245", thinnest front or rear wall .085", thickest front or rear wall .210"
-----------------------------------------
7-this is a 400 SBC that I built into a 382ci engine in the late 1980's with intentions of about 575 honest HP used 4.132" bore size with NO corrections to help the wall thicknesses:
-thinnest thrust wall .154", thickest thrust wall .301".
-thinnest and thickest front or rear wall wasn't measured becasue of the siamesed bores.
-but there is five grooves down the bore walls inside the water jackets below the headbolt holes and the thinnest groove is .145" and the thickest groove is .238"
-(haven't ever used this engine yet)
-----------------------------------------------
8-a 390 Ford after bored .030":
-thinnest thrust wall .150", thickest thrust wall .174", thinnest front or rear wall .090" thickest front or rear wall .166"
---------------------------------------
9-a 4.3 V6 Chevy marine:
-thinnest thrust wall .174", thickest thrust wall .257", thinnest front or rear wall .129", thickest front or rear wall .194"
-----------------------------------------------------------
-typically the thickest front or rear walls is at one of the front or rear cylinders.
---------------------------------------
1-brand new 454 marine block, one of two in a twin engine Reggie Fountain 33 foot toy:
-thinnest thrust wall .215", thickest thrust wall .286", thinnest front or rear wall .105" thickest front or rear wall .255".
2-the other 454 block in the same boat:
-thinnest thrust wall .217", thickest thrust wall .273", thinnest front or rear wall .152", thickest front or rear wall .241"
---------------------------------------
3-another 454 passenger car block:
-thinnest thrust wall .293", thickest thrust wall .357", thinnest front or rear wall .131" thickest front or rear wall .305"
---------------------------------------
4-283 chevy bored out from 3.875" to 3.990" with the bores moved offcenter to save some of the wall thicknesses:
-thinnest thrust wall .135", thickest thrustwall .204", thinnest front or rear wall .103" thickest front or rear wall .216"
---------------------------------------
5-a 307 bored out from 3.875" to 3.930" with intentions of going to 4" and the bores centerlines were also moved to save wall thickness:
-thinnest thrust wall .209", thickest thrust wall .245", thinnest front or rear wall .113", thickest front or rear wall .209"
------------------------------------------
6-one 350 block I used for several years as a fairly serious oval track engine in the 1980's, about 500 honest HP:
-thinnest thrust wall .196", thickest thrust wall .245", thinnest front or rear wall .085", thickest front or rear wall .210"
-----------------------------------------
7-this is a 400 SBC that I built into a 382ci engine in the late 1980's with intentions of about 575 honest HP used 4.132" bore size with NO corrections to help the wall thicknesses:
-thinnest thrust wall .154", thickest thrust wall .301".
-thinnest and thickest front or rear wall wasn't measured becasue of the siamesed bores.
-but there is five grooves down the bore walls inside the water jackets below the headbolt holes and the thinnest groove is .145" and the thickest groove is .238"
-(haven't ever used this engine yet)
-----------------------------------------------
8-a 390 Ford after bored .030":
-thinnest thrust wall .150", thickest thrust wall .174", thinnest front or rear wall .090" thickest front or rear wall .166"
---------------------------------------
9-a 4.3 V6 Chevy marine:
-thinnest thrust wall .174", thickest thrust wall .257", thinnest front or rear wall .129", thickest front or rear wall .194"
-----------------------------------------------------------
-typically the thickest front or rear walls is at one of the front or rear cylinders.
Last edited by InfernalVortex; 02-22-2012 at 01:53 PM.
02-22-2012, 01:52 PM
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Re: Rebuilding the 350.. again
Put a bottle of Barr's in the rad and some Lucas in the oil and that'll close right up.
02-28-2012, 12:32 PM
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Re: Rebuilding the 350.. again
Well, the machine shop is seriously taking FOREVVERRRR its actually getting extremely annoying. But whenever I get this all back, I get to send them my crank to get balanced and THEN, FINALLY, I will rebuild this thing. In the mean time whenever I pick the block up in the next few days I'm going to re-paint it and consider painting my valve covers.. not sure yet. Also might get a different air cleaner or get a duel snorkel setup to an airbox or my foglights. Any input on how these work on carb'd motors?
03-02-2012, 12:59 PM
#49
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Re: Rebuilding the 350.. again
...Well summit racing has failed me again. They sent me the wrong rods so I ordered the right ones and will be returning the wrong ones today. Machine shop is still slow as ***** so.. I'll probably have my motor/heads/and crank back by the end of next week.. On the bright side, There is nothing on the bright side as of now. I don't even want to know how much they are going to charge me at the shop, even though they have been slow as hell.
03-07-2012, 12:36 PM
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Re: Rebuilding the 350.. again
Got the block back today, looks great. Will take pics when I get off work. Bringing in the flexplate and harmonic balancer tomorrow so they can balance the crank.
