I am in the process of gathering parts for a new engine build up, and I hope you guy's can answer a couple questions . The planned engine is a regular 350 small block . The block itself is a 4 bolt main,cast in 1978 ,I think it's a truck block.The block was given to me free ,from my older brother(thanks Mick).I plan on reusing the stock cast crank. I micropolished it myself with fine grit sandpaper/ solvent and a shoe lace . The crank will be magnafluxed and checked for straightness at the machine shop.I will also be reusing the stock rods.The beams will be ground smooth on the sides and polished by me and they will be resized by the machine shop and magnafluxed.Should I go with forged pistons ,or hypereutectic? should I use press fit pins? molly rings?The block will be .030 over ,it will be decked,torque plate honed, and the mains will be align honed.I plan on using tri-metal bearings. This leaves the cylinder head and cam selection.As of now I have two sets of heads,casting#461 cast in 1968 with 72 cc combustion chambers,that are bare,and casting # 882 which are complete . Which heads should I use to get the best low end torque?Although I plan calling comp cams for a cam recommendation, what cam#/specs would you guys go with?Iplan on using roller rockers. I'm building for low/ midrange torque. Edelbrock dual plane intake-Edelbrock 795cfm quadrajet,15/8 inch headers,Flowmaster mufflers. Trying to build this as cheap as possible.Wish I could find some vortec heads at the junkyard.So if some one could give me some advice on the above questions(Iknow there is a lot)it would be greatly appreciated. Let me know what you run in your 350's and also any past builds. As of right now , Iam not going to use a stroker kit-that's for next time.Thanks
CK5
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GEN 1 SMALLBLOCK QUESTIONS
- Thread starter 4xfrankie
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everybody's still sleepin'!
What is your maximum rpm range? that will be a big question Comp will want to know.
For an offroad truck with a small block I would build for low and midrange as you have mentioned.
If you want to run mud or sand, more rpm would be desirable.
all the block and bottom end work sounds real good, I'd go with a forged piston for the durability. I'd do the moly ringset as well.
If you have to have head work done, consider a decent set of aluminum heads and bump the compression a bit.
those 461's are only 64cc heads, the 882's are 76cc's
the 461's don't have an X on the underside of the intake port do they?
What is your maximum rpm range? that will be a big question Comp will want to know.
For an offroad truck with a small block I would build for low and midrange as you have mentioned.
If you want to run mud or sand, more rpm would be desirable.
all the block and bottom end work sounds real good, I'd go with a forged piston for the durability. I'd do the moly ringset as well.
If you have to have head work done, consider a decent set of aluminum heads and bump the compression a bit.
those 461's are only 64cc heads, the 882's are 76cc's
the 461's don't have an X on the underside of the intake port do they?
In my opinion, you don't need to spend $$ on pistons. If the budget is there, find better heads.
In my opinion, forged pistons are a waste for your build. Hypereutetic pistons are pretty good stuff and will be more than you need.
Thank you for the input!! Everyone on this sight seem like real good people(as the Donald would say)Idon't know why everyone is so uptight over there on PIRATE4X4 ,they act like your inconvieniencing them!Dude basically told me to do a google search- he wasn't gonna serve up answers on a silver platter! (terrible people, terrible people ) from what I got on a google search these particular heads have 76cc but maybe Iread it wrong.These heads have the un hardened valve seat right? What is your opinion about vortec heads?My truck is going to be used as an Ultimate adventure type vehicle for all types of wheelin. I would like to have a compression ratio that would allow low grade fuel-87 octane ,so what do you think 9.5:1?
Vortec heads are WAY better than the heads you have, but require a different intake manifold, valve covers, and even pushrods and rockers if I remember right.
Everybody has there own opinion so here's mine. The #461 heads you have are "Double Hump" heads, and have 64cc chambers instead of the 72cc you mentioned. The #461 double hump head was a very desirable head to have back in the day, and can still make a damn good set of heads today. My sugestion for budget build use the #461 heads. You could put bigger 2.02 INT valves and 1.80 EXH valves, but this cost more money. Go with hypereutectic dished pistons because of the 64cc chamber heads, flat top pistons will be to much compression. I personaly go with steel rings for street engines. Then get a COMP RV type cam which has about upper 270 to low 280 range advertised duration. I would skip the Edelbrock Quadrajet, and get an Edelbrock Performer 650 CFM, with a good electric fuel pump that has built in regulator. The regular Edelbrock Performer street carb is not a good carb for off roading though, If you plan on doing off roading with your vehicle it is worth spending the money to get a carb built for off roading.
OK that's what I thought , the vortec is what I was after , but these heads were free and I think I will go with them later when I can get them (vortec) out of a junk yard. Do you see any disadvantages in using a vortec head?
Carcinogen
1/2 ton status
I think you can "get away with" using the stock pushrods, but watch the lift on the cam you choose otherwise your in more money making sure you don't get any binding. But it would probably be best to list to Chris and NOT me...
There are tons of write ups all over the internet for the vortec swap if you want exact details. I personally like this write up, it has tons of info but its not truck specific.
http://www.nastyz28.com/forum/showthread.php?t=56505
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You can get both sets of your heads to have flow numbers as good as vortecs by going to 2.02 INT and 1.80 EXH valves, which is what people had to do in back in the days your heads where manufactured, in order to make horse power. But, they will never have an efficient burn rate of fuel as vortec's because vortec's have swirl port technology along with semi-cathedral intakes runners, which is why you can get away with higer compresstion ratios on vortecs, and not your heads. With your heads I would recommend nothing higher than 8.75:1, if you plan on running regular grade gas.
I am not sure if your #882 heads require self-aligning rocker arms. If they have screw in rocker studs, with push rod guides, then you can get a set of "long slot" stamp steel rocker arms to make sure you do not have rocker arm bind with a higher lift cam. If you do not have rocker studs, then your #882 heads require self-aligning rocker arms. The only long slot self-aligning rockar arms are roller rockers. A company called 'Scorpion' has the cheapest and best quality self-aligning roller rocker arms, in order to prevent your rocker arms from slamming into the rocker stud from too much lift. The previously mentioned RV cam I recomended should come with a lift in the nieborhood of .460" lift, which would need longer slot rocker arms.
I am not sure if your #882 heads require self-aligning rocker arms. If they have screw in rocker studs, with push rod guides, then you can get a set of "long slot" stamp steel rocker arms to make sure you do not have rocker arm bind with a higher lift cam. If you do not have rocker studs, then your #882 heads require self-aligning rocker arms. The only long slot self-aligning rockar arms are roller rockers. A company called 'Scorpion' has the cheapest and best quality self-aligning roller rocker arms, in order to prevent your rocker arms from slamming into the rocker stud from too much lift. The previously mentioned RV cam I recomended should come with a lift in the nieborhood of .460" lift, which would need longer slot rocker arms.
Ok , after digging out the heads that I thought were 461 casting number , Ifound out they are actualy casting number3932441 they are in really bad shape , had to spray easy off and wire brush to get a better look at the number. These heads will require quite a bit of work to get them in good running order-machine for hardened valve seats,bronze valve guids, will get machined so I run umbrella seals instead of the O-rings on the valve tip ect. After I get all this stuff done(as well as getting them milled flat and magnifluxed for cracks , will it exceed the price of vortec heads?My friend that lives down the road from a fairly large junk yard in Tilton IL said he has pulled three sets of vortec heads, and they were all cracked but one head. He told me that even though the vortecs have excellent ports/ combustion chambers and all that they are still considered a "lightweight" head and are prone to cracking, esp. after getting milled. MY 882 heads are in the best shape, and will probably just need new seals , and then the valves lapped, which I can do myself.So Ihave decided, to use them for now and get a set of hypereutectic pistons. Since the 882 heads have a 76 cc combustion chamber I will get flat tops.The 441 heads might get put on craigs list, how much are they worth? Or Imight try and do my first porting job on them and have 2.02/1.60 valves installed .
I haven't had any machine work done in quite some time, but if I was, I'd make sure I needed to have the block decked before actually doing it. Flat top pistons are really where you want to be if you can run them, doubtful in hyper. that they are more costly in any meaningful way than dished. Flat is ideal, but not a requirement. You aren't going for maximum power, and you need to ensure you will end up with a compression ratio that doesn't make you run gas you don't want to pay for.
Never really understood the desire to deck anything if unnecessary, except that with zero deck and an ~.040" compressed head gasket you don't have to do any thinking to get ideal quench. But head gaskets in about any thickness are available, running .025" deck height (which is normal) with a .015" head gasket is doable, and just about anything in between.
Engine building tends to be a pretty opinionated topic, everyone has what they prefer to do, or what has worked for them.
One thing I didn't understand when I built mine was quench, and that might have made the engine a bit more resistant to detonation than it is. The other was that one piece rear main motors are superior in terms of leaks. But sounds you are pretty well stuck with what you have. It's hard to beat free.
Never really understood the desire to deck anything if unnecessary, except that with zero deck and an ~.040" compressed head gasket you don't have to do any thinking to get ideal quench. But head gaskets in about any thickness are available, running .025" deck height (which is normal) with a .015" head gasket is doable, and just about anything in between.
Engine building tends to be a pretty opinionated topic, everyone has what they prefer to do, or what has worked for them.
One thing I didn't understand when I built mine was quench, and that might have made the engine a bit more resistant to detonation than it is. The other was that one piece rear main motors are superior in terms of leaks. But sounds you are pretty well stuck with what you have. It's hard to beat free.
Well ,I think that the decks should be milled to square up the block, and give the block/heads an ideal mating surface for head gasket sealing. Other wise ,you have to establish the right deck height to maximize quench.So I'm pretty sure you want the deck height as much as close to zero as you can as long as you obtain the right piston to valve clearance.Since this is going to be a low RPM engine, and I am not going to run a crazy high lift cam I should be able to get away with less deck height and therefore more quench, without having to worry about the valves hitting the pistons,correct?I haven't had any machine work done in quite some time, but if I was, I'd make sure I needed to have the block decked before actually doing it. Flat top pistons are really where you want to be if you can run them, doubtful in hyper. that they are more costly in any meaningful way than dished. Flat is ideal, but not a requirement. You aren't going for maximum power, and you need to ensure you will end up with a compression ratio that doesn't make you run gas you don't want to pay for.
Never really understood the desire to deck anything if unnecessary, except that with zero deck and an ~.040" compressed head gasket you don't have to do any thinking to get ideal quench. But head gaskets in about any thickness are available, running .025" deck height (which is normal) with a .015" head gasket is doable, and just about anything in between.
Engine building tends to be a pretty opinionated topic, everyone has what they prefer to do, or what has worked for them.
One thing I didn't understand when I built mine was quench, and that might have made the engine a bit more resistant to detonation than it is. The other was that one piece rear main motors are superior in terms of leaks. But sounds you are pretty well stuck with what you have. It's hard to beat free.
I think decking may be used interchangeably or incorrectly instead of surfacing. You can true up a surface without taking off a bunch of material, just depends on what kind of shape it's in. Heads are the same way, they may be near flat, or require a bunch of material removed to true them up.
Without knowing everything to include all the cam specs, pretty much impossible to determine what clearance is going to be. Pretty much everything factors into that, which is one of the reasons you are supposed to check clearance with clay and a weak spring on a valve to ensure clearance is acceptable.
With "normal" production parts and a mild cam, I don't think it's common at all to have piston to valve clearance issue. Realistically, in terms of deck height, GM ran .025" deck height, with a .015" gasket/shim. If you zero deck the engine, and run a ~.040" compressed head gasket, you are exactly where GM started. Now milling heads, changing cam lift, and any tolerances stacked up in rockers/springs/lifters among other things could all influence clearance.
Without knowing everything to include all the cam specs, pretty much impossible to determine what clearance is going to be. Pretty much everything factors into that, which is one of the reasons you are supposed to check clearance with clay and a weak spring on a valve to ensure clearance is acceptable.
With "normal" production parts and a mild cam, I don't think it's common at all to have piston to valve clearance issue. Realistically, in terms of deck height, GM ran .025" deck height, with a .015" gasket/shim. If you zero deck the engine, and run a ~.040" compressed head gasket, you are exactly where GM started. Now milling heads, changing cam lift, and any tolerances stacked up in rockers/springs/lifters among other things could all influence clearance.
If you're sticking w/ cast crank, it wouldn't be of huge benefit to go w/ forged pistons. If you want budget heads, summit has some house branded world products torque sr heads that have somewhat decent flow capability - heavy though because they're iron. http://www.summitracing.com/parts/sum-152123
So, you want the best deck height that allows for the most quench, without the piston tops hitting the head ,and factor in head gasket thickness, and after all that ,say your piston to valve clearance is tight, you then must have the valve reliefs opened up some to alieviate clearance.right?
Yes I was considering forged pistons for strength,but they are too much money . Iheard that hypereutectic pistons are pretty brittle. but as long as Ikeep the engine out of detination, I should be o.k. Now Ihave to figure out what compession ratio to run ;76 cc chamber w/ x amount of head gasket thickness and a flat top piston to arrive at 8.75:1 for 87 octane.
