350 build opinions

[RustyBuckets]

Thanks to all of the advice ive gotten on my 350.

I have attached some pics from my build, pulled a bunch of goodies and im down to the cylinders, turns out she has been cut .040.

Cylinders look good, so I hope everything holds up to the compression boost from some vortecs... once i pick some out.

Under the valve covers what quite a bit of creamy sludge, I hope some new heads and gaskets will fix this and my exhaust smoking problem

 

[HotRodPC]

So there is still lots of crosshatching in the cylinders? This would be a good indicator of a lower mileage motor and it should hold up to the higher compression if so. I just wonder how or why you might have blown a head gasket, possibly cracked a head or what is the cause of the creamy junk you're talking about? Are you assuming something may be wrong with the current heads or gaskets? Was it overheated? I'd sure get a straight edge and check the block decks for being flat and square.

What I'm getting at, is if it's a mid mile motor as far as mileage and wear, maybe you should go ahead and yank it. Go thru the block too with some new bearings and rings. A good ball hone job to renew the crosshatch pattern and maybe some chromolly rings. If in spec, it'll be as good as a brand new motor with a new timing chain set and oil pump.

Worse case scenario, just go with the heads for now. If need be, you can yank it in 10,000 miles or so if the rings didn't hold up and still have the good heads ready to bolt on the newly re rung motor.

 

[Tyger13us]

So there is still lots of crosshatching in the cylinders? This would be a good indicator of a lower mileage motor and it should hold up to the higher compression if so. I just wonder how or why you might have blown a head gasket, possibly cracked a head or what is the cause of the creamy junk you're talking about? Are you assuming something may be wrong with the current heads or gaskets? Was it overheated? I'd sure get a straight edge and check the block decks for being flat and square.

What I'm getting at, is if it's a mid mile motor as far as mileage and wear, maybe you should go ahead and yank it. Go thru the block too with some new bearings and rings. A good ball hone job to renew the crosshatch pattern and maybe some chromolly rings. If in spec, it'll be as good as a brand new motor with a new timing chain set and oil pump.

Worse case scenario, just go with the heads for now. If need be, you can yank it in 10,000 miles or so if the rings didn't hold up and still have the good heads ready to bolt on the newly re rung motor.

I agree,, prolly a cracked head,, them ole smog truck heads are famous for it..

but he said it smokes,, and is .040 over,, new heads will wake it up and more than likely stop the smoking,, but the blow by???

the ring grove @ the top of the cylinders would give a better clue on condition? and if he can see the rings looking down the side of the cylinders? its got milesssssssss on it..

I often look to see the ring end gap,, and yea ya can see them,most of the time, or? do an oil in the cylinder test,, rotate the motor and ya can really get a good look at the ring gap by the trail it leaves......

but it sounds tired to me and will prolly have blow by,,, im not saying it wont run,, it will!! it will run really good,, loose ole sbc's run excellent,, and then run a road draft tube or a catch can and no pcv!!! ..

 

[Tyger13us]

Thanks to all of the advice ive gotten on my 350.

I have attached some pics from my build, pulled a bunch of goodies and im down to the cylinders, turns out she has been cut .040.

Cylinders look good, so I hope everything holds up to the compression boost from some vortecs... once i pick some out.

Under the valve covers what quite a bit of creamy sludge, I hope some new heads and gaskets will fix this and my exhaust smoking problem

in the bottom pic i see? ether a cracked head or a bad head gasket on # 5..

cant make out much more without better pics....

 

[RustyBuckets]

If you look closely you can see the piston in #5 on bottom pick, it was very clean, all of the rest had black carbon build up.

i tried measuring deck height by setting a speed square(carpentry triangle)
flat across piston at tdc lowest number i could get was .035 which sounds to high

and it wasnt the easiest but i pulled the cam out without pulling the motor

 

[HotRodPC]

If piston #5 was clean and the rest had carbon build up, that tells you there was a head gasket or cracked head near the #5 cylinder and an adjacent water jacket. The water/coolant lightly leaking into the cylinder is converted to steam from the heat from combustion and pressure. In short, #5 piston was steam cleaned where the others were not. I'd certainly have that head checked out with a good magnaflux and also check the deck surface of the block for being flat. You might need to have the block decked a few thousandths.

 

[RustyBuckets]

whats the best way to check deck surface

 

[HotRodPC]

Straight edge and a feeler gauge or piece of paper. If you can lay a straight edge across the deck and slide a .010 feeler gauge under it at any point then it needs decked. If you don't have a feeler gauge, then use a piece of paper folded in half doubled up. If anymore than that will slide under the straight edge, meaning if it slides under the edge loosely, I'd get it decked. Composition head gaskets will compensate for a little bit, but if it's not 100% true, then I sure wouldn't consider a metal thin gasket without having the block decked. By looking at the pics, I'd be concentrating on the area by the lower round water jacket between cylinder 3 and 5. It's appears that's where the failure was. You can tell by the color on the deck. And the real problem may been on the head side of the gasket instead of the deck side. It very well could be and hopefully nothing more than a head gasket failure and the deck and the head be just fine.

 

[Tyger13us]

Straight edge and a feeler gauge or piece of paper. If you can lay a straight edge across the deck and slide a .010 feeler gauge under it at any point then it needs decked. If you don't have a feeler gauge, then use a piece of paper folded in half doubled up. If anymore than that will slide under the straight edge, meaning if it slides under the edge loosely, I'd get it decked. Composition head gaskets will compensate for a little bit, but if it's not 100% true, then I sure wouldn't consider a metal thin gasket without having the block decked. By looking at the pics, I'd be concentrating on the area by the lower round water jacket between cylinder 3 and 5. It's appears that's where the failure was. You can tell by the color on the deck. And the real problem may been on the head side of the gasket instead of the deck side. It very well could be and hopefully nothing more than a head gasket failure and the deck and the head be just fine.

yep,, and looks to me that the lower bolts,, the one under #3 and the 2 under #5 wernt torqued correct........

Id Highly suggest that ya buy a new 7/16 coarse thread tap and chase ALL the holes in the block and clean um up real good,, wire wheel the threads on the bolts also,, if the threads are rust eaten,, i find some other ones to use..

id also use the blue silicone felpro head gaskets,, IMO,, id never use a thin metel head gasket on the street........

 

[HotRodPC]

yep,, and looks to me that the lower bolts,, the one under #3 and the 2 under #5 wernt torqued correct........

Id Highly suggest that ya buy a new 7/16 coarse thread tap and chase ALL the holes in the block and clean um up real good,, wire wheel the threads on the bolts also,, if the threads are rust eaten,, i find some other ones to use..

id also use the blue silicone felpro head gaskets,, IMO,, id never use a thin metel head gasket on the street........

That's great advice. I'd chase all the head bolt threads. Sometimes the extra drag from a dirty thread will throw your torque spec measurement off and leave a loose bolt. And again, Ty is correct. It could very well have been an improper torqued head bolt that caused the failure in the first place. Sometimes those issues don't show up or come to light for thousands of miles.

I also like those Blue FelPro PermaTorque head gaskets. They got raised silicone built into the gasket that does a very good job of sealing and do offer forgiveness for an imperfect deck or head plane. Unlike say a cheap Detroit or Mr Gasket comp gasket. They don't have the raised sealer around the water jackets. I always encourage someone to spend the $60 on a FelPro engine gasket kit rather than the cheap $25 engine gasket kit. You'll not only find the materials the gaskets are made of are better, but the fit is also better and more accurate in many cases. You get what you pay for. and gaskets, espeically head gaskets, is not where you want to skimp.

Composiiton gaskets are just fine for street or dd motors. Only way I'd even consider using steel shim head gaskets is if it were a street/strip race motor I was building and I was concerned about that little bit of compression I could gain, and to do that, I'd want the heads and block deck resurfaced to be 100% certain that they are true. Then you have to be concerned if your intake is going to fit correctly depending on how much block deck was removed and head surface was shaved off.

 

[cedens]

http://www.summitracing.com/parts/mll-bp3830ctc/overview/

I may get crazy and go this route, not the SB 400, or even one converted to the 383 but still a 4 bolt main

 

[Tyger13us]

http://www.summitracing.com/parts/mll-bp3830ctc/overview/

I may get crazy and go this route, not the SB 400, or even one converted to the 383 but still a 4 bolt main

the only thing ID ever do with a 400 is use it for a boat anchore,, throw it over board,, then cut the rope when it was time to go......

the cranks are weak,, really weak,, Siamese cylinders go oval,, the wrist pins are to far up in the pistons and cause the pistons to rock and bust scurts on cast pistons,, they always over heat cause of the way the water flows throughout the block and head and i wouldnt turn a sb400 ANYTHING over 5 k rpms...

i know people who have tryed really hard to make a 400 "Work" but it was an abortion from the start,, lot of waisted time and money......

Id go with 383 in a heart beat,, but i built my 357 cid to be a timex.....

its tough,, reliable,, and proven,, plus parts galore @ any parts store or wreaking yard/someones back yard junk.......

JMO,,,,,,,,

 

[cedens]

I liked the torque on that one, the price looks decent for a nice crate with all the dressings on it.

420 FtLBs and about 400 HP on the engine dyno

Definite upgrade from 275lbs with 165HP it has now which still runs great, have done some tune up on it (mostly new fluid plugs and filters) and she's got some of her old pep. but i miss my old 03 Stepside with the 325 (5.3 L) i could chirp tires at 45 MPH but it governed at 99 MPH Those IIRC put out about 320 HP and if it wasn't so much work time and money i'd think about, all i have is a shade tree my 24 x 24 garage is packed.

3 riding mowers (5 acres of lawns here) 2 push mowers, a 4 wheeler, 81 Yamaha 650 and a Honda "trail bike" or Passport. along with a crackerbox welder, huge welding table tool boxes, chemical cabinet and shelving of junk ... and all the christmas decorations that don't make it to a shed.

 

[HotRodPC]

The SBC 400's did have some issues. I do know they'll run and make some good drag race motors if done right, but NO, I wouldn't want one in my daily driver or roundy round race motor. If you like the stoke of the SBC400, which is where all the torque comes from in the first place, is the longer stroke, then just go with an aftermarket stroker 383 rotating assembly kit. You can get them already balanced, crank has been crossdrilled and chamfered etc. The sky is the limit as to what you have order your kit with. Stock con rods all the way up to Aluminum H beam rods. Then find you a good 350 block. If you're going for mega horsepower, I'd go with a 2 bolt block, and then have it retrofited with splayed 4 bolt mains and line bored, along with a main girdle or at least straps. Now that's getting into some into some heavy duty horsepower to need all that, but it can be done. There's a guy here in OKC running in the 9's with a 383 in a Vega, carrying a wheelie half track.

 

[Tyger13us]

I liked the torque on that one, the price looks decent for a nice crate with all the dressings on it.

420 FtLBs and about 400 HP on the engine dyno

Definite upgrade from 275lbs with 165HP it has now which still runs great, have done some tune up on it (mostly new fluid plugs and filters) and she's got some of her old pep. but i miss my old 03 Stepside with the 325 (5.3 L) i could chirp tires at 45 MPH but it governed at 99 MPH Those IIRC put out about 320 HP and if it wasn't so much work time and money i'd think about, all i have is a shade tree my 24 x 24 garage is packed.

3 riding mowers (5 acres of lawns here) 2 push mowers, a 4 wheeler, 81 Yamaha 650 and a Honda "trail bike" or Passport. along with a crackerbox welder, huge welding table tool boxes, chemical cabinet and shelving of junk ... and all the christmas decorations that don't make it to a shed.

yea,, thats a good price for a turn key motor.. ive got close to 8k in my motor,, 3k in just the heads!!,, it adds up quick with all the extra goodies..

ive got the same problem,, out back under a shade tree or 2,, no garage,, man i wish i had one though,, this damn heat ya cant get nothing done,, ya gotta go out just before sun up and ya gotta quit just before noon,, i just cant take the heat anymore,, then the rest of the day is waisted......

ive got 2 acres of sage brush 10 trucks,, from 74 up to 86,,with alot of spare parts collected from here and there,,, a retired pontiac sunbird sport coup that needs a cage before it goes back on the road,,a couple toys,, and ole 64 fiberglass beach buggie,, a dr 250 suzuki dirt bike,, and a golf cart i want to convert to gas and make a go-kart out of,, ive got plenty to do,, but no shop to do it in.......