Thread: SBC 350 build

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Originally Posted by jerry clayton

a much more critical rate of camshaft effects are the DECELERATION rates as the tappet nears the full open and also the closed area---one to elininate the valve from flying off rocker/pushrod/lifter combined diminsions and the other to eliminate bounce as the valve seats.

Thanks Jerry, I never addressed the other side of the lobe, just interested in making the point that an extreme energy grind will work the lobe and lifter harder than a gentler grind and is not particularly necessary on a street motor in today's world in my opinion.

If nobody brings up the downside of a more radical lobe profile, these youngsters are going to think it's a free lunch.

I agree 100%....

I was able to controll the urge to get carried away with the duration on the cam...unfortunatly I went with the extreme energy cam and now I wonder how long till the seats are gone or worse yet, the valve head is embedded in the top of the piston......Hopefully the rhodes lifters take some of the bite out of it.

just another good reason to go roller cam

Alright, so I'm thinking, I'm going to bite the bullet and do a complete rebuild of the motor reusing the block, crank and connecting rods. **Pistons are pending on what is in the block. ** I've decided I will bite for the extra few dollars and added security and go with a retro fit hydraulic roller cam. I'm going to do this engine right so i will be pulling it and borrowing my dad's 355 that's sitting on a stand in the shed while i build my 350. Nothing is set in stone of course but what i'm thinking so far is:
-new bearings all around
-D cup pistons- KB193
-Magnum Hydraulic Roller retro-fit (model, lift, duration to be determined when things are moving along a little down the road)
-Edelbrock Performer RPM Vortec intake
-Vortec heads with COMP beehive springs and 1.5 roller rockers
Should I get self aligning rockers or ones that use guide plates? The self aligning are only a couple bucks more than ones that use guide plates on summit.

Assuming my deck height is stock and stays the same with the KB pistons, I worked out a 9.57:1 compression ratio with 0.015 fel pro gaskets using summit's compression calculator.

While i rebuild the motor, I will be putting my transpak in my TH350 and 2500 stall converter (the 355 is putting out over 400hp and about 430ft/lb torque). Then I will do the gears in the rear end and hopefully my 350 will be ready to drop in once that is all done.
Thanks again, everybody for your posts. Everybody's opinions are appreciated.

Originally Posted by Bowtiepickups

I've decided I will bite for the extra few dollars and added security and go with a retro fit hydraulic roller cam.

I think you'll find that the best deal going on a retro roller will be from Howard's Cams, about 500 bucks for the cam and lifters. Most of their stuff is ground on a 112 degree lobe separation angle. You can install the centerline anywhere you want to though, when you are degreeing the cam in the block. Advancing it 2 or 4 degrees will add to the bottom end while detracting from top end performance. Retarding it 2 or 4 degrees will add to the top end and sacrifice some of the bottom end grunt. If you have to advance or retard more than 4 degrees to get where you want to be, then you have installed the wrong cam. Speaking of degreeing the cam, here is a tutorial that you should study until you know it by heart...
http://www.iskycams.com/camshaft.php

You might want to consider starting with a roller block. If you could find a good L31 short block with the roller lifters, dogbones and spider and the lifters were in good shape, you could be money ahead by not having to buy lifters, just buy the cam that will work for your combination and SCR. The added benefit would be the one-piece seal, as opposed to the two-piece seal in the earlier blocks like you have. If you don't do everything just right on assembly, the two-piece seal will leak and there's nothing worse than to get a motor together and running and find that you have a leak at the rear seal.

Originally Posted by Bowtiepickups

Should I get self aligning rockers or ones that use guide plates? The self aligning are only a couple bucks more than ones that use guide plates on summit.

The cheapest way to do it would be to pin the studs and use rail rockers. To use conventional rockers, you would have to remove the studs, mill down the pad on the head by the thickness of the guide plates, then drill and tap for screw-in studs with guide plates. Something has to keep the rocker tip centered over the valve stem tip, either a rail rocker or guide plates that keep the pushrod centered, which keeps the rocker centered. I don't think I would want to use rail rockers with a wild camshaft, but with what you are considering building (probably less than 0.525" valve lift), I would be ok with rails.

You'll have to determine if it is worth it to install roller rockers or use conventional stamped stockers. The advantages of rollers would be less friction generated, thus, less heat in the oil and the fact that they would be a true 1.5 ratio. Stockers will normally check less ratio than the engineers specified, sometimes as little as 1.4 according to some fellows, so you would not be getting the full valve lift that the camshaft was designed to produce. The downside is the cost and the fact that the rollers are not as durable as stamped steel rockers. Some fellows have experienced them coming apart and scattering little roller bearings throughout the motor. If you do run rollers, it's a good idea to epoxy some brass screen material over the oil return holes to catch the rollers before they go to the pan. Some might slip past and go down the pushrod holes, but hey, you do the best you can with what you have to work with. The screening can also catch shrapnel from fragged springs or retainers.

I searched around for the best price on Scorpions for you, seems like they have taken a giant leap in price since the last time I looked. Some ebay vendors are asking 300 bucks for a set. Anyway, the part number for a narrow-body (to fit inside the L31 valve cover), self-aligning, 1.5:1 ratio set of 16 is SCP1035. Mountain shows them as SCP1035-1 for 270 bucks. Click the blue oval that says "Update Price"....
http://www.mountainperformanceonline..._p/scp1035.htm

Originally Posted by Bowtiepickups

Assuming my deck height is stock and stays the same with the KB pistons, I worked out a 9.57:1 compression ratio with 0.015 fel pro gaskets using summit's compression calculator.

OK, first I want to make sure you learn the proper terminology. There is "block deck height", which is the measurment from the centerline of the main bearing bore to the flat deck of the block where the heads bolt on and is usually around 9.025" on a virgin block. Then there is "piston deck height", which is the measurement from the piston crown to the flat deck of the block where the heads bolt on with the piston at top dead center and will usually be from zero to 0.050", with an average of maybe 0.035". I know you will hear fellows say just "deck height" without specifying which one they mean and most of the time, in that case, they will be talking about the measurement from the centerline of the main bearing bore to the block deck. But I want to teach you properly, so whenever someone says "deck height", ask them whether they are talking about block deck height or piston deck height. They might look at you like you have two heads, but they are the ignorant ones if they don't know the difference. Now, as you know, ignorance can be cured by teaching and learning. On the other hand, stupidity goes all the way to the bone and is terminal.

To do the thing right, you would first align hone (or align bore if the register is way out of whack) the main bearing bore in the block. This will take out material between the centerline of the bearing bore and the centerline of the camshaft bore. If enough material is removed so that the timing chain will be sloppy, there are timing sets that are a little shorter to take up the slack. Then you would measure the block deck height. Normally, you will find that there is a fairly large discrepancy from one end of the block to the other. Sometimes the machinist at the factory did not get the register cleaned out of all the chips from the previous block and the block decks will be machined uphill/downhill. I personally have seen 0.014" on a 429 Ford block and I'm sure Pat McCarthy and Jerry Clayton have seen worse than that, as many engines as they have built. When you deck the block to bring it back to square, that's when you measure all the components (rod journal throw, rod length and piston compression height) in order to set your piston deck height according to the gasket you plan to use so you can set the squish between 0.035" and 0.045".

If you think about it, you can see where the intake manifold would not sit on the heads properly if the deck was tilted uphill/downhill. I think sometimes that is what makes an internal vacuum leak happen. This is where the outside of the intake manifold is pinched pretty well at the cylinder heads, but on the other end of the port, on the crankcase side where you can't see it, the gasket may not be squeezed and the intake ports are pulling in not only air from the carburetor, but also oily air from the crankcase. This can make you nuts if you don't know about it, because no amount of spraying a combustible material such as propane around the intake manifold will find an INTERNAL vacuum leak.

Now, another good reason to deck the block and maybe even take a skim cut on the heads is if you are going to use a shim gasket. You mentioned using a 0.015" gasket. That's a shim gasket, not a composition gasket. While a composition gasket will tolerate some wavy action on the deck and heads, a shim gasket is not as tolerant. Both the decks and the heads need to be pretty flat and smooth to insure that the motor won't spit out the shim. Just be aware.

you want to deck the block when you know the CH of the pistons your going to buy or have C.H is compression heigth pin center line to the flat part of the piston .i messure the deck off the BHJ tru plate .i seen decks up and down hill and off on angle from side to side .the BHJ tool is centered thu main s and cam bores this gets the block back to were it needs to be .not doing this your building a block no better then gm or the maker of the block .i have seen blocks off over 018 from side to side from main to cam to deck .when i get the deck were it needs to be then i put the bores 90 off the deck .this is the only way to build one.in photo you can see the part of the BHJ thru deck the angle this what you set up the cutting head to so then your true .push rods . heads .intake . piston bore are as good as they can be now that you have some place to start thats true .some boring bars mount off deck and some off the oil pan rail .if deck or oil pan rails are off and they are .... your bores will be off that why i deck them first

Originally Posted by pat mccarthy

just another good reason to go roller cam

After doing a non roller, all I can say is that I will never intentionally build one without a roller cam again....soo much less stress and worry...still worry about it after the break in on mine.


Roller all the way!


Tech brings up a very good point.....and that is to try and get a one piece rear main seal block already set up for a roller cam.

You might be money ahead doing this as those engines are pretty cheap from the boneyard and you could leave your running engine in the truck untill the new one is built, no double engine removal then.......then use the parts from the old block such as intake etc, whatever you plan to re use.

If you have a running vehicle----then buy a machined block from someone---you can get late model roller blocks, dog bones, seal adapter(I bought all the billet adapters from K-tech for puting 2 pc seal cranks/pans on late blocks) and hold down plate( even used roller lifters)

I buy these blocks from 9 -18 at a time from a core supplier---its much simpler than cleaning up the oil/coolant mess from the customers engines brought in that aren/t drained properly.

If your interested PM me and I'll give you Corey's contact.

Jerry

PS You aren't very far from Pat----you should go pick up from him

I was actually thinking today about going to see my dad's buddy. He owns a truck wrecker and I could probably find a newer 350 that has a roller in it, in his yard and only pay about 100 bucks for it. I could get the block machined and still run the 350 that's in my truck now. Then I could build up the roller block a bit slower so I wouldn't be shelling out a ton of money all at once. And while the machine shop had the block, I'd get them to bore it .030 over too so I'd have a 355 I'm thinking this would be a better option for me as cash flow will not be the greatest once I have to put insurance on this thing and put gas in it. And after all that, I'll have a 2nd 350 block sitting around. I'm thinking this will be the route I take.

Some times on a well worn engine it's better to trade in the core on a Re-maned Built Shorts Block . There was a Place out by me called the Chevy Shop . I sold that Guy a Few Short Block cores that needed to be Bored out . He had a Floor Full of Built up Short Blocks all Bagged up read to go . From Bored out 305's to 454 SB's 2-Bolts- 4-Bolts you name it . And for cheaper then it would Cost you to have one Built . 355 4-Bolt Mains with hyper Pistons Rebuilt Rods decked Aligned Bored with HV oil pump and Hardened Shaft $700.00 OEM Rollers and Early Gen 1 Blocks .

Originally Posted by Bowtiepickups

I was actually thinking today about going to see my dad's buddy. He owns a truck wrecker and I could probably find a newer 350 that has a roller in it, in his yard and only pay about 100 bucks for it. I could get the block machined and still run the 350 that's in my truck now. Then I could build up the roller block a bit slower so I wouldn't be shelling out a ton of money all at once. And while the machine shop had the block, I'd get them to bore it .030 over too so I'd have a 355 I'm thinking this would be a better option for me as cash flow will not be the greatest once I have to put insurance on this thing and put gas in it. And after all that, I'll have a 2nd 350 block sitting around. I'm thinking this will be the route I take.

Just keep in mind that you need the pistons for them to finish bore the block you bought.I does somewhat make more sense to buy a later yr roller engine over buying the conversion kits for the earlier engines.The thing with some of the earlier blocks they where a harder casting.


Hummm-now the next shoe that drops.Bought a roller engine for a build as you can,355 or 383??.

Originally Posted by 1gary

Just keep in mind that you need the pistons for them to finish bore the block you bought.


Hummm-now the next shoe that drops.Bought a roller engine for a build as you can,355 or 383??.

Noted. Thanks for reminding me of that. I guess they wouldn't be able to machine it to any kind of spec without them. Haha.

I'm thinking I'll pick up the roller engine, tear it down, grab a set of .030 over pistons and take that to the machine shop and get the rolling assembly set up. Then it's just a matter of buying top end pieces as I can afford them until I have everything bought but heads, then swap my vortecs with the comp springs over and drop it in. Should be a nice little 355.

Originally Posted by tango

Some times on a well worn engine it's better to trade in the core on a Re-maned Built Shorts Block . There was a Place out by me called the Chevy Shop . I sold that Guy a Few Short Block cores that needed to be Bored out . He had a Floor Full of Built up Short Blocks all Bagged up read to go . From Bored out 305's to 454 SB's 2-Bolts- 4-Bolts you name it . And for cheaper then it would Cost you to have one Built . 355 4-Bolt Mains with hyper Pistons Rebuilt Rods decked Aligned Bored with HV oil pump and Hardened Shaft $700.00 OEM Rollers and Early Gen 1 Blocks .

You got to know you DO get what you pay for.Right???.The deals in the long run aren't.Just because a guy buys bulk in re-buildable blocks,doesn't mean he provides the same quality at a cheaper price.Buy a Jasper if that is what your thinking is.

Chevy Bob Built Engines for Many-Many Years . He also Ran a Speed Shop out of that Location . Because of all the Parts He Bought . He could Pass on the Lower Prices to his Customers . Sure if you Needed a Forged Crank and Pistons maybe Studded Mains the Price went up . That man always was fair to us and his Shop Truck was a Testimony to his Work He always wanted to Race us 1gary you Need to Lighten up some If I Live Near you I would Build that 350 for your R.V it would work just Fine even with a Flat Tappet Camshaft COOL

Originally Posted by tango

Chevy Bob Built Engines for Many-Many Years . He also Ran a Speed Shop out of that Location . Because of all the Parts He Bought . He could Pass on the Lower Prices to his Customers . Sure if you Needed a Forged Crank and Pistons maybe Studded Mains the Price went up . That man always was fair to us and his Shop Truck was a Testimony to his Work He always wanted to Race us 1gary you Need to Lighten up some If I Live Near you I would Build that 350 for your R.V it would work just Fine even with a Flat Tappet Camshaft COOL

I'm sorry.I didn't explain to you after 40yrs in high performance engines I don't need arm chair glossy magazined paged mechanics help and least of all yours.A national event win in super gas and a number of local champs over 20 yrs to my credit.I know what you know about engines.You make it very evident in everything you say..............


But no more off topic subjects to this honest O/P's thread.I disagree with you about cheaper isn't just that.Cheaper.The concept is based on pure common business sense.A business that isn't different than any other just because it happens to be about engines.So the Jasper answer I gave leads me to believe is a better engine than your ref and therefor a better value.Of course production run package deals isn't what this forum is about.Right??.Yeah leave it as it is.I disagree with you.