jmadison

ok guys heres the deal. My goal is to be between 375hp-400hp. What i have is a 350 sbc that was already bored 60 over. I have absolutly no idea what is in it. This is my first engine build. i will be taking all the parts off down to the block then work my way up there. just a forewarning, i need to know what all i will have to buy such as heads crank pistons so on and so on. i need to know what all needs to be dona at a machining shop as well as a likely price. Im obviously trying to keep this as inexpensive as possible, although i know more power = more money. It would also be greatly appreciated if you can leave websites for me to find what i need. I need every little detail that you can give me about what i need. Feel free to throw any ideas at me. however, i would like to have carburated rather than tpi. and im sure alot of people have different opinions about that. if someone has a 350 bored 60 over, you could just give me your complete build list as well. thanks in advance for your help and suggestions.

vetteoz

iTrader: (13)

First up you need to strip the motor and measure the bores to see if you can stay at 60 over.
If not the block is a throwaway as you don't usually bore a SBC more than 60 over ; especially if you want to make power , the cyl wall thickness becomes too thin
Crank also need measuring as well to see if machining or replacement is needed

60 over is no different than any other 350 build except for the size of the pistons (+60)
A Google search will bring up plenty of documented 400Hp 350 builds, use them as a guide for required parts

jmadison

if its bored 60 over what do i need to measure the bores for? im not trying to be complicated, ive just never done this before. how do i know if i can stay at 60 over? i want to put a new crank in it but have absolulty no idea of what type, size, or where to find them online. im worried bout getting one that might not fit my engine since its bored 60 over
. thanks for the fast response though!

birdman_29

iTrader: (1)

You need to measure the bores to double check on the size. Because if it is definitely bored .60 over than tearing it all down to the block you might find out that the bores might need worked on. An in that case if the cylinders need to be bored more to clean them in the shop, than your getting your self in thin water. Bottom line is .60 is the max that you should get a block bored out at, at least a 350 sbc. An most don't even recommend that. So before you dump alot of money into the build get the bores measured and checked.

InfernalVortex

iTrader: (4)

1. .060 inches overbore is the max you can go for a smallblock chevy. Many wont even go that far.

2. Over time the bores go out of round, they wear into a slight oval shape. This hurts ring seal. In order to restore roundness to the cylinder walls, during a rebuild the machine shop will just literally bore the whole thing out until it can be made perfectly round again. Then you buy larger pistons to compensate. The maximum recommended overbore from GM for their blocks is officially .030 over. Some will take it to .040 and some to .060. Just depends on how much you want to risk thin cylinder walls as to how far you're willing to go with a factory block.

3. So the machine shop will measure the bore at several different places and directions up and down the bore. If it's within spec, you can get away with just a hone and throw it back together. Even that can be risky depending on how close to the edge you are with that block's cylinder walls.

4. Common overbore sizes are. 010, .020, .030, .040, and .060.

5. Bore size has no bearing whatsoever on crankshaft size. So you're fine on that front. The bore size affects the pistons you choose and NOTHING else. At .060 you will need to take a little care selecting a head gasket, but beyond that nothing special is needed to accommodate the bore.

6. Given my experiences with .060 blocks... I'd tell you to use the block for parts and skip that block for the next one you see. Look for something newer with less wear. Like a roller block.

1gary

A competent machine shop will insist on having the pistons you buy in hand before boring anything so they can size the bores to the pistons.

vetteoz

iTrader: (13)

My reference to the crankshaft was in relation to ;
if the block is now out to 60 over then crankshaft may also have been machined to it's min spec in past rebuilds

InfernalVortex

iTrader: (4)

Ah, I see now. that's a good question, fortunately it has a simple answer. Theres no real correlation there.

Cankshafts usually only need attention after catastrophic damage, and that damage may or may not have happened at some point in that crankshaft's life. The difference is crankshafts wear but due to the oil film and bearings on them during operation, they don't see any physical friction unless something fails. Cylinder bores see constant friction and wear, and old carbureted engines didn't fuel them as accurately, resulting in more wear over hundreds of thousands of miles. (In fact, it's not uncommon to get a 85+ fuel injected block and need to go .010 over or less, whereas with 70s and older blocks, .030 was usually the minimum, )

Crankshafts wear, but not in a linear, predictable, significant fashion the way bores do. Its not uncommon to find them 10/10 or 20/20 though, with one number representing the journal undersize on the rod bearings and the other on the main bearings.they dont need to be same, either. you can have the stock size journals on the mains and undersize journals on the rods. I think it was a David Vizard book I read that advocated turninga crank undersize as much as possible to facilitate a good radius from the journal to the counterweight. He had some reasoning why this was a great thing, but Im not sure it's worth messing with as there were a few caveats.

Some shops will stamp the crank for the journal sizes, but dont count on that or count on that being correct.Basically, you will have to either measure it or have someone else measure it. But that goes for almost anything in a used engine anyway. Dont buy parts unless you measure first.

jmadison

i now have a much better understanding. thanks everyone for the help!

Atilla the Fun

Fail, and you should know better, even if the OP doesn't. JE was making forged 70-over pistons before there were any aftermarket blocks with siamesed 4" bores. Cast 80-over pistons have been around since the early '70s, and are still readily available. From experience I can say that such a build will survive 400-HP street duty for years. JE and others now have 65-over on the shelf.

1gary

All these companies are in business to sell parts.Just because those parts are available doesn't make it a correct tactic for a re-build and the one one or two of a kind re-builds doesn't justify them either.If you sonic check the bores and they measure below the minimums,then the block is junk.Also it is almost not worth the effort to take that "chance" of a block being useable being bored larger that .060 over when a new core at a stock bore is so cheap to get let alone getting a roller block.

Atilla the Fun

Sonic-checking the SBC wall thickness at 0.060"-over on a '70s 350 isn't necessary to know it's still safe for a 400-HP build. The parts wouldn't be shelf items if there wasn't steady demand, and wouldn't stay in demand if there were problems with using them. You obviously don't know jack about circle-track claimer engines, or what kind of abuse they see. Sustained running at 6800 RPM with Vortec heads and bottom-of-the-page cams are entry-level builds. These surviving multiple seasons at 70 over should tell you something. None of us do 15-minutes at a time above 6500 RPM on the street. I know what these blocks usually show for wall thickness, and the results prove it is plenty. So who are you to say it isn't thick enough? Same thickness giving problems on some 455s? Yep. But we aren't considering a 455, we're considering a '70s 350. Better to ask questions than making wrong statements.

1gary

We've bought those "claimer" parts out of Syr auction from the Parts Peddler swap meet for over 20 yrs and sold the ones we bought at the Indy Race racer auction. We have sat at dinner with the same outlets you talked about for about the same amount of time. Some are friends.Sooooooooooooooo. Your wrong. I spoke about sonic checking .070 overs and not .060's. We have been in no small part a part of the high performance industry for the same amount of time. Ya just never know WHO ya going to meet on these forums.

Now I have always wonder about your "on probation" under your user............

Oh our policy is when we are not doing the machine work in person to error(if even it is a error) to advise on the safe side. THAT is .060. Been a standard for yrs and yrs.

tylercamaro

iTrader: (1)

i havent built a ton of engines, but sonic checking would be a must if i were to go anywhere near .60 over.

as for original statements, take your block to an engine builder, buy your full rotating assembly once you know what your doing and have them spec everything out for you, if they rebore the meains ask them what types of bearings you need size wise.

i would have them balance your engine while they have the lower end too. they can take care of measuring bores, decking heads, and checking any clearances you may be unsure of. it will cost you quite a bit tho for the full treatment to your block, but in the end if you build it right, it will be completely worth it.

1gary

Yep Tyler.The O/P has a block bore out without having the pistons in hand.The question is if he can find a set of pistons to mate up with the bore.I agree.The best move for him is to take it to a trusted machine shop for them to find a set of pistons.

tylercamaro

iTrader: (1)

wait! the block is already .060 over and it doesnt have pistons?!?! or hes taking it in to get it bored without them? if its already that far i wouldnt even use it. it would end up as an end table, anchor, volleyball post wieght, or mailbox. any GOOD machine shop that knows what they are doing wont touch a .010 over bore without having matching pistons first.

1gary

Yep.That is the problem.He bought a block already bored .060 and didn't have the pistons.

tylercamaro

iTrader: (1)

block=trash

find a virgin bore or close to virgin bore one, no matter than ..020 over if it were me and use that one. assuming a block is good because its already bored for larger pistons is no-no number one. as for any knew engine build you need to do alot of reading and research before you jump to any big purchases or conclusions about how something is suppose to work. it sucks i know im 19 and i was in the same place 3 years ago. its not fun but it make a world of difference learning your stuff and doing your research first.

InfernalVortex

iTrader: (4)

I had a cylinder bore crack on my early 70s "010" 350 block after cam break in when I took it around the block. Dumped a ton of water into the oil. I will never use a .060 over block again. Some may be perfectly fine, but when you can get a new 1 pc RMS roller cam prepped 350 block for the same or a little more money, the total cost of which pales in comparison to the machine work investment, I think it's a no brainer to just trash anything beyond .040.

GM only recommends .030 over on factory Gen I blocks these days, and I trust modern metallury and machine work far more than 70's era machinework and quality control.

for the record, I bought my block used from a guy who had to tear it down because he had a crack in his cylinder heads. He thought it was the block, but his new build had the same problem and he finally found out it was the heads. It had 3000 miles on that build before he ended up tearing it back down. I took the block to the machine shop and they checked it out (they didnt have a sonic checker, though) and gave it a fresh hone and everything looked perfectly fine. Looked fine to them and it looked fine to me.

I even had to abort my first build because I ended up buying a junker set of overported heads (courtesy of dans87gta and shagwell ) that were welded up and polished up to flip. Another lesson - never buy ported heads. They even pressure tested fine, but as soon as the hot exhaust heat hit the welds they cracked and started pouring steam out of the tailpipes. (the bore that was cracked was not one of the 3 ports that was welded up, btw). I pulled the heads and replaced them with another set and the bores looked fine then too. Got a new set of heads and finished break in and the oil was clean and the engine ran fine. Then went around the block once and parked it til I could get back to finishing it all up the next weekend, and the oil was milky.

Found a cracked #6 cylinder bore.



Theres no telling how thin the walls are, and just because it's a "70's" block doesnt mean diddly.

1gary

I'm not ready to tell this O/P his block is a total write off.If the engine is taken to a good machine shop and checked out and if that machine shop can find a set of pistons to fit the finished bore he has,he might be able to salvage this situation.
The sonic check is a way of projecting if there is enough meat to spend the labor costs do the machine work.
Pressure testing is a way of checking to see after the work was done if there are cracks
Mag testing should reveal cracks fairly easily.

I knew of only one place in Boston,Mass that has a long,long,history of effective welding of cast iron.To do that you really have to know your metals.(well isn't that true of all welding??)But with cast iron you have to know just the right amount to pre-heat the repair area and just the right amount to post heat the weld.Of course it has to be the correct heat selection for the weld too. It is very labor intensive and very costly if done right. Some guys have epoxied cracked heads with varying success.The factor of finding oem ported heads that were cracked is telling that oem heads do not have alot of rm to be ported before you have water issues.It is one of the main reasons why the aftermarket heads came into existence. Yeah the resident hot rod historian in me can remember that development time period.LOL. Yrs ago the Mondello heads for SBC's was the hot ticket. Man we sure where in caveman tech back then.

tylercamaro

iTrader: (1)

i agree with gary, even for sopmeone relatively knew to the engine building game like me theres stuff was you get your mind set into researching stuff that you just pick up on. if he can find a set of heads to match the bores then amen to him...that is if the sonic and magnufluxing checks out.

ive found it to be alot harder and costly to find pistons to match a bore than a bore to match pistons.

jmadison

hold on guys. sorry for any misunderstanding here. i have the 350 bored 60 over. i got it from a friend in a 87 trans am gta. it ran amazingly! VERY fast. the spark plugs started arching n then it was running like ****. at that point, i then decided i wanted to rebuild it. the engine still sits in the car as of right now as im getting an engine hoist next week hopefully. i did tear the engine down to the heads, but didnt want to go any further until i get my engine hoist. so there are pistons in it as of right now, i will check when i remove the engine, but right now im assuming they are the right pistons as what should be in it. The heads tho, im not really sure. This engine has power, just not as much as i believe it should. the friend i got it from says that he dont believe the "computer is tuned appropriatly". maybe that has something to do with it too. my plan is so far, to take the engine out of car. get it torn apart to bare block. take it to a machining place and get it hottanked and checked for anything wrong with it such as bore size ext... IF everything checks out there, i would then like to find the proper set of heads in the case that the ones on there are not the correct ones that should be used. pistons are not AS expensive so i was gonna get new ones anyway. Can somebody tell me, from your experience/knowledge, what size/type/description of heads, and pistons i need. I also know nothing about the other parts such as the "cam", "crankshaft" ext. Dont get me wrong, you all have helped greatly and i hope you'll keep doing so.
on a side note, i did want to mention i am also thinking about finding a bare block 350 that hasnt been bored over n abused, and starting from there. any comments/suggestions are always welcome
jim

tylercamaro

iTrader: (1)

with a .060 you cannot buy new piston heads! any well built engine has the bores fit around the pistons so if your gonna buy new piston heads you need the bores to match which is not do-able with an already .060 engine.

start with the bare block and youll be happier, engine will have a longer life etc. find yourself a roller block go .020 or .030 over and put on a ported set of vortecs or something like that depending on how much your willing to throw at it.

do.not.use the already .060 block. its bad news bears. run it as it is and let it destroy itself but dont rebuild it. the wall thickness is already thin, rebuilding it wouldnt make sense to me.

jmadison

[QUOTE=tylercamaro;5389791]with a .060 you cannot buy new piston heads! any well built engine has the bores fit around the pistons so if your gonna buy new piston heads you need the bores to match which is not do-able with an already .060 engine.

i dont understand because its bored 60 over and they have pistons that are 4.060 bore.....standard chevy 350 block is 4.000 bored 60 over is 4.060, why would new pistons not work in it?

jmadison

will be posting pics/dimensions/info tomorrow for rockers pushrods and also the number displayed on the heads. i mostly need help with the heads to see if maybe thats why im not getting the power i should be out of this engine

1gary

Technicality you should have the pistons in hand before you bore the block/finish hone.Pistons do vary that much that you want those sizes.Because you have a block .060 over already,the standard limit is .060 over.Some guys on here are going to disagree with that.But the point is with your .060 bore,to find another set of pistons to fit your already bored block has the potential of a issue.

Rest assured my advise is based on spending your money wisely at the lowest risk possible. We have built all kinds of motor sports engines(and some larger than .060 with the understanding it was totally at the customers risk),but in general we hold the bores at .060 for reliability.

Hope this helps you understand better.

jmadison

ok i understand. i copied down the head numbers and lookup them up.
14102193 Chevrolet Cylinder Heads Small Block V8 1987 305 or 350, 1.94/1.5 valves


how do i know if those are the heads that should be on there or if i need different ones n thats y im not getting my potential hp out of this engine????

InfernalVortex

iTrader: (4)

Agreed. The block may be fine. I just dont like the idea of someone telling him "oh it's a 70's block dont worry about it!" when I've been there, done that, and had to pay a bunch of extra money to fix it. If he can get it sonic checked Im all about using it, but there's a lot of caveats to rebuilding a block that's already .060 over as you're discussing. Just wanted him to know that cylinder wall thickness isn't something you take for granted.

Those heads are terrible. They were good for 200hp stock, and are just larger valve versions of the TBI 305 heads. They are great for low end torque and good on gas because they have these weird swirl ramps in the intake ports, but GM took that idea and took it to a whole new level with Vortec heads and it works FAR better. The swirl ramp helps port velocity and gas mileage but it severely impedes flowrates despite having a fairly large port volume. They are servicable because they have 64cc chamber and will allow for reasonable compression ratios, but flowrates aren't great with them and they will keep the power down. They have great exhaust flow so if you know what you're doing you port the entire swirl ramp away and make them work pretty well, but very few people bother with that. The work it takes and the gains you get... it's a lot easier to just go aftermarket or get some Vortecs or even some 083 heads (stock on F-body L98s) or maybe some 113 heads (aluminum stock stock on Corvette L98s from 87ish to 91, comes on the ZZ4 crate engine too, I think).

As a block wears, the friction and crank rotation etc put side loads on the cylinder bores, and it will oval them over time. This hurts ring seal. When you rebuild you just bore it out until it's round again. If you want to go to a 4.010 bore, the machine shop actually bores it to 4.009 basically. And then the honing machine (Adds the crosshatching to the cylinder bores. The crosshatching is what causes the piston rings to seal when new) adds the final extra bit to get it to the correct final size of 4.010. But different pistons are slightly different size. These are small numbers, but generally you want to measure the pistons or use the manufacturer's measurements for recommended final bore specifications and match the bore to hte pistons. In your case, your bore is already .060 over, and already a little worn. you may not be able to bore it farther. Your new pistons may be too small. That's not ideal, but it's not the end of the world as long as it's close ,and most likely it will be fine. You can even re-use your old pistons as long as they're not damaged (I would do this).

Ideally I would have told you to leave the bottom end together. The best pistons to fit that block are already in it. But once you tear it down, you gotta deal with a rehone to get new piston rings to seal properly... so you've at least got to do that, and your pistons will probably be ever so slightly too small. Is this a tragedy? No. It will most likely be fine, but if you're trying to win races its something you want to avoid.

Should you get a new block that isnt worn out? Your call. But if you can find one that's set up for roller cams you are way ahead of the game.

Otherwise as far as the "right" parts to make it go fast, there are many, many, many different ways to do that. What's the right route to take to get from Nebraska to Oregon? There are infinite ways to go there.

1. What's your budget?
2. What's your power goal?
3. What's your usage for the car?

You gotta find a happy medium between those 3 things and from there you can figure it out.

1gary

It sure would be of interest to find out where you are with the engine as it stands now.

jmadison

ok... i now understand how use of an engine can oval the cylinder, thus it then needs bored slightly to be backe to circle. 60 bore, the walls are already really thin, one would then hesitate at rebuilding such an engine with the high risk of loosing money, and the engine its self. If i am to pursue the idea of rebuilding this motor, i would need to take it to a machine shop have them check it to see if it needs an additional bore. also need to check for any cracks, uneven wear ext.... if it does need bored again, it seems it would be smarter to find a new motor to rebuild. however, if it doesn't need it, i would then have then check the pistons to see if they can clean them up and make them almost like new so i can save money. If that all checks out, i would then need to find a set of heads, as infernal had informed me, those heads ain't got what i'm looking for. I am looking into aluminum stock 113 heads at this point. Do i need to do anything with the cam???? im not sure whats in it but my guess would probably be stock along with the heads..... if you do suggest cam replacement, what ones would you suggest? Also, if i get 113 heads, can i use the same pushrods, rockers, ext??? If not ill have to get one that is fully assembled. With 113 aluminum heads, what would be a good intake that would fit, keep in mind, carbureted. Would i just need standard 350 valve covers? or tall ones? thanks for all the help and understanding as i jump into this feet first, its great to know i got some support.
by the way, this is in no way gonna be a primary vehicle, and also will never see snow. my budget is 2-3 thousand. power goal....as close to 400hp as possible. but also keep in mind, this is gonna be a long project for me, not just something where ill have it done next week. Right now, my primary focus is making a blue print pretty much of exactly what parts im gonna have such as the 113 heads, what cam, what valve covers, what intake, what carburator ext.... i want to have this whole thing mapped out first as i try to be very organized in the work that i do. another question, how can i know if a block is set up for a roller cam or not. im gonna guess the one i got is not a roller cam...how can i tell? and what would i have to do to put a roller cam in this one? is there alot of alterations or replacment parts needed for this?
jim

jmadison

right now, the engine is still in the trans am. i have it tore down to the rockers. the heads are still on it because the exhaust manifold is connected to it and i got it disconnected from the heads but they are still connected to the exhaust pipe so i cannot take the heads off. i tried disconnecting the manifold from the pipe but i cant figure out what size the two bolts are....i know that sounds like im retarded. i tried 5/8=too big, 1/2=too small, 9/16=just barely to big to where it slips off. i then thought they might be metric which i have a bunch of metric sockets but none of them are deep well like my standard sockets. I have most wiring disconnected from engine. once i get the exhaust manifold off, im gonna take the heads off then unbolt the engine from the transmission and remove the motor mount bolts n get her yanked out. its dark out right now or i would put pics up of most my parts. Ill be sure to take some tomorrow for yall.
jim

jmadison

whats the higher number compared to lower number of "cc' do on heads? the higher the number, the more power? how do u know what cc u need for optimizing performance without trying to make a dragster? lol im definatly looking at vortec but from there, im lost lol
jim

InfernalVortex

iTrader: (4)

You choose combustion chamber cc's to fit your desired compression ratio. Ideal compression is different for different uses, cams, heads, etc. You choose intake port cc's to fit your camshaft/displacement/RPM range.

In regards to compression levels which are mostly controlled by chamber size and piston dish size, most commonly with a street car is 9.0-10.0:1 for iron heads and 9.5-10.5:1 with aluminum heads (maybe a little higher, but it's better to be conservative here). That ideal range will change with different camshaft selections too. You have to balance everything. But generally with a 350 you'll want 58cc aluminum heads and 64cc iron heads. Understand that this is like saying "To get the best gas mileage, go 53 mph", there are TONS of other factors to be worried about here. These are GENERAL guidelines just to get you started looking at things. Dont just buy something because it matches a number I gave you, there's a lot more to it than that, but use it as a guideline to start looking into things.

If you have flat top pistons (With valve reliefs), look at 64 cc iron heads and 58-64cc aluminum heads.

Also, understand that all the best heads are aftermarket like AFR, Brodix, Dart, Trickflow. Any factory head is comparatively garbage. The Vortec 906 and 062 and the L98 083, 113 are pretty much the cream of the crop for factory heads. They're good, but not great.

jmadison

ok thanks ill definatly keep that in mind. i never woulda guessed there was so much to go together to make an engine work. thanks yall. pics will be up later today
jim

tylercamaro

iTrader: (1)

if your bores are ovalled chances are you arent gonna get to bore them out much more thats why weve all been saying get a new block with a virgin bore.

whats your budget is what most of this comes down to. if you call up AFR telling you the exact specs and everything of your engine they can find something for you that will max most of your motors potential. alot of companies wil do that on a basic standpoint.

have you even chosen a cam yet? what compression ratio are you going with? what type of piston head are you using? those all come into play when building an engine that runs good.

scrap your whole .060 black and idea. .060 means nothing more than your block was bored that far out.

if you run vortecs, have them port and polish them for you, opens up a bit more potential the heads can have in my opinion.

what cam is in the engine now? if you cam it, youll likely have to put a stall in it too.
as for intake it depends what your use of the vehicle the engine is going in is for. also with vortecs you need a special manifold that will only work with vortec heads. they are different compared to any other sbc manifold or head for that matter.

roller blocks started around 1988 when they went to 1 piece RMS. look up the vin on the block, if its anything 70s or low 80s chances are its not a roller block.

valve covers dont matter at the slightest about an engines performance, as long as they clear your rockers it boils down to visual taste.

tylercamaro

iTrader: (1)

hold on, you said cam and heads may be stock? if they are stock type .060 over piston heads they are smoggers, so in order to acheive your 400 hp goal youll need new ones meaning yes youll need a new block that can take a new bore. if your doing all that id suggest going .030-.040 over tops. get a roller block 88+ from what i understand.

for your cam if its stock the heck yes youll need more. and the more cam you have the bigger stall you need in your transmission.

InfernalVortex

iTrader: (4)

Stop giving bad information. The fact that the heads are stock and the block is .060 over means NOTHING in relation to each other. It could have 083s or 882's. It means nothing. Besides he already identified the heads as 350 TBI swirlport heads (193), which came on 87(ish?)-95 truck 350s.

Stop using the term "piston head", it's confusing and it isnt common nomenclature. The term you're looking for is, I think "piston", but sometimes it's hard to tell if you mean piston or head, and both are very different things.

And they do all play a factor in coming up with a good build, but it's not rocket science. But what you do NOT do is pick a cam, and then pick everything else the way you imply. You pick a desired power level and budget. Find the best parts you can, then figure out how fast you need to spin it to hit your power goals, and how mild you need to keep it to make it streetable, and then you set your camshaft and compression goals and heads based on that. The cam, heads, compression ratio, intake all depend on each other. You have to match everything. He doesnt even know what heads he needs so you shouldnt be encouraging him to pick out a cam... that comes later.

Why? Most of the time when people port vortecs they ruin the port velocity characteristics that make them so good to begin with. Now you can port the exhaust, but there's just not much point to it. It's real easy to mess that up and end up with boat anchors. Porting vortecs is generally a bad idea. Even the junk ported set I had they left the intake ports alone completely. I would never advocate porting vortecs, and I'd never advocate a newbie pay the moeny to have someone else port heads or learn to himself. Just expensive and risky and the gains arent that big. He'd be better off just buying another set of heads.

tylercamaro

iTrader: (1)

i said them take it to you a shop to do it for you, ive ported heads before not vortecs but an old set of darts and a few other. and one mistake and they are good as trash. the absolute most id do on vortecs is clean them up a little, nothing more, i wouldnt start porting them to hell like you mentioned. yes for what you can have a shop rework your heads for you your better off going out talking to a few companies and seeing what they can offer you with the goals and information you give them

i didnt know he already idnetified the heads but none of that is gonna get anywhere near 400hp. swirl ports suck even with some work to them they still suck. they a 1.94 and 1.5's and dont flow worth a darn. they have good lower torque for an engine that isnt high on performance but other than that they arent good for anything.

i never meant to say pick your cam then start schoosing stuff. sorry to bunch up your panites but no need to get all uptight. its not bad information yes what you said is correct but you need to know what cam to run once you have all the figured out, if you have everything golden such as rpms,cr, etc etc and run some small peanut cam what good is that going to do you.

he asked about cam, i dont think he knows that the bigger cam he runs(which i large cam may not be neccesary) hell need to run a stall. he has 14 different questions in one paragraph. if my questions werent answered then id get sorta antsy. hes learning so basic answers for now while focusing on one main point is what needs to be done. as far as i know we are still on the whole piston/block debate which i believe he finally understands.

TTOP350

iTrader: (8)

Looks like just a rust stain to me. Did you pressure test that block to make sure?


Tylercamaro; What the heck are piston heads????

InfernalVortex

iTrader: (4)

I cleaned it up more later. It is rust becuase water was seeping through the water jacket there and sat for a few days, but it's rust because that was the source of the water. The heads were steam cleaned in that bore and they pressure tested fine afterwards. They've been put on my new block with no issues for years.



Also here's another picture of it.



The clear stuff in the other bores is where I was spraying wd-40 through the ports because I didnt have time to tear it down farther a few days and it was REALLY humid out. One of those 3 days of bleak rain crap we get here in the south occasionally.



As far as getting the block pressure tested, I didnt see the point. I could feel the crack with my fingernails. The backside of the cylinder walls were just too thin, old, and probably rusted up to hold after the hone they went through to fit my new pistons and my new build in it. I thought I could make a .060 over build work because I replaced hte pistons with the same brand/part number as the pistons that came out of it, but it needed a hone to make sure the rings would seal, and thats what pushed it too far. It had issues before it was torn down but that was due to a crack in the cylinder heads that allowed exhaust gas into the cooling system, but it didnt allow coolant into the block. He dealt with that for a while even on his new build. But it ran very strong for 3000ish miles before he tore it down and that crack didnt manifest itself until AFTER I finished camshaft break in. Neither I or the machine shop saw anything in that bore before then.

The heads look a little weird in that picture, like something bounced around in there, but it was just due to the really short amount of run time it had with that crack in it. Less than 5 minutes probably, and it was under no load. I checked the valve seats and cleaned up the chambers and there was no damage anywhere, no evidence at all of anything metal bouncing around, and I know how meticulous I was putting it together so I felt I could rule that out. It didnt crack until I drove it around the block and put a load on the engine. The cam break in was fine and the oil was clean then. There was no evidence of oil/coolant mixing til after I took it around the block. A cracked bore was the only answer that made sense and the evidence fit that hypothesis.

InfernalVortex

iTrader: (4)

Vortec intake ports are best left alone completely. 1.94 and 1.5 valves are fine for the vast majority of even performance builds. Beyond that, you're right, he's a newbie and asking a lot of questions at the same time, but when you have someone like that you have to be careful what you say. Its real easy to give someone the wrong idea or misrepresent things unintentionally.

tylercamaro

iTrader: (1)

pistons, i work alot with old car guys and they say it. it gets to be second nature i guess. you get past the confusion with them, you cant really tell them differently so you just accept it.

jmadison

will have pics up in about an hour. i didnt forget. also i got the heads taken off. i got one exhaust manifold off n im working on the other one as the bolt to attach it to the exhaust pipe from under the car is REALLY rusted on. i did get a 15 metric deep well that fit it though. pics to be up soon guys.
jim

1gary

With iron heads I set the DCR@ 8.5.Some guys push the envelope to 9.0 but that is asking for possible problems.

jmadison

pics

jmadison

more pics

jmadison

some more pics

jmadison

last of the pics

mr.350

so a sbc 350 bore .040 over enough to make good hp?

jmadison

I BELIEVE.... the bigger bore, the bigger pistons, in turn the bigger options for bigger hp. however 60 over is great potential for power, but with the thinness of the cylinder walls, you take a higher risk at everything u just put money into to going to ****. from what i heard so far, in my opinion a 350 with a 40 bore and the correct combo of parts would rersult in great power. then if u ever needed to bore just a little more later down the road the walls wont be to thin in the cylinder and u should be able to add a slight additional bore to fit around new pistons and to make sure its circle not oval. i may be wrong as im new to this but this is what i have learned so far to my understanding.
jim