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 Page 4 of 4 « First<1234
Username Post: Rebuild a Chevy 350 or buy a crate engine?        (Topic#325239)
Droff 
Forum Newbie
Posts: 42

Age: 55
Loc: Choctaw, OK
Reg: 05-28-15
09-19-16 06:17 AM - Post#2652111    
    In response to Droff

I found a local 383 I was thinking about checking out but wanted some input on a few of the components.

- 4 bolt
- Forged flat tops
- Scat rotating assembly balanced
- Comp cam solid lift camshaft 560 570 lift
- World product sportsman 2 heads 2.02 1.60, valves been shaved 0.050, have comp screw in studs an guide plates
- 0.80 comp 0.100 longer pushrods
- 1.5 comp stainless roller rockers with poly locks
- Weiland speed intake
- No carb

I don't have info on compression ratio, haven't talked with the owner yet.
The lift specs of the cam look like it might be awful rough for a street car. Would this engine be too much for just a street vehicle?




 




LUVmachine 
Frequent Contributor
Posts: 1453

Age: 36
Loc: Redding Ca
Reg: 10-02-14
09-19-16 06:50 AM - Post#2652119    
    In response to Droff

Those heads came in more than one variation. If they were 64cc combustion chambers and milled and depending on what flat top pistons were used your compression ratio could end on the high side. Not to mention what intake runner size they are and depending on what headers or exhaust manifolds you are using or plan to use you could run into fitment issues if they are angle plug heads. I personally have a thing for not buying used engines and if I do I pay core prices and treat it as a core. Too many dishonest people out there that looking for someone to rip off. Do your homework and try to figure out what it is you are getting and try not to get ripped off if you decide to buy the thing or else you will probably spend more money trying to make changes. Usually what seems like a good deal at the time will cost more in the end unless you are buying from a trusted source.

71 Chevelle BBC powered
71 C-10 454 with weiand 177 (SOLD)
72 406 sbc powered Chevy LUV sleeper (SOLD)
2010 GMC Sierra crew cab 4X4
http://s626.photobucket.com/user/GJohnson81/libra r...


 
Shepherd 
Frequent Contributor
Posts: 1296

Loc: Lake George, NY
Reg: 11-11-15
09-19-16 08:28 AM - Post#2652136    
    In response to Droff

You need the cam duration at .050 lift to determine it's driveability. 64cc heads with that combo could yield too much compression, you can get a calculation chart on line to get close to the compression ratio. Luv machines advice is on target, I would pull the pan an look a some bearings not just buy the engine and gamble.



Edited by Shepherd on 09-19-16 08:30 AM. Reason for edit: No reason given.

 
0utlaw 
Very Senior Member
Posts: 2789
0utlaw
Loc: US East Coast
Reg: 09-10-02
09-19-16 08:34 AM - Post#2652140    
    In response to Droff

  • Droff Said:
I've been getting the fire hose treatment from all the threads and links, a lot of information to go over..
I've got a 1970 Monte Carlo with a 350 in it, auto transmission, open rear end with highway gears, 2.73. I have a pretty bad oil leak either from the pan or rear main. My plan was to change the pan gasket first and see if that solves my leak but I'll still need to lift the engine to get the pan off.
With this in mind, rebuilding thoughts started creeping in. I have a friend that has a used crate engine, 350/260HP, that he has in a '74 El Camino with about 28K miles, and might consider selling it to me if I go that route.
I have yet to rebuild an engine and know very little about matching components together so everything functions as efficiently as it can, that's one reason why a crate engine is a thought.
I'm not afraid to rebuild an engine, it just may take a while.
What I'm looking for is a street car, no strip, something that runs strong, will smoke the tires when I want and is fun. Maybe drive to work every now and then or run in town with it. At some point I'd like to run around 3.30 gears when I can find a good rear end.
I have a torn down 350 block in my garage and the 350 in the car, so a few options.
Any suggestions on a path?


I'll just mention that SOMETIMES oil will leak out the back of the intake manifold (rear manifold seals CAN fall out of place) and run down the back of the block and drip in the area in back of the pan (sometimes difficult to see)...and make you think the pan is leaking. It's worth verifying the leak exactly. If so..it is an easier fix. Lots of Chevies leak there.
Anyway....
I think it is a mistake to buy an engine seeking hp unless you are racing. (Rough idling motors sacrifice low end torque.) I would hope you keep your eye on torque and the rpm that the torque is made...especially for a heavy car. A good torque motor will pull your present rear gear. A good rv cam will build torque...and still spin tires..yet give decent mileage. Head in this direction and you will like the results better.



 
Ray P W 
Contributor
Posts: 356

Reg: 09-30-15
09-19-16 09:16 AM - Post#2652147    
    In response to Droff

Droff,

Here's one Chevy Talk member's crate engine horror story:

http://www.chevytalk.org/fusionbb/showtopic.php?ti...

So while there may be a warranty on those crate engines, having a warranty and getting it honored by the seller can be worlds apart. I personally don't need that kind of drama and have always chosen to rebuild a good core, either one I had or one found for next to nothing on Craig's list or at the local Chevy dealer.

If you have a competent engine shop to do the basic machining and balancing, buy quality parts and assemble everything yourself you will end up with something really nice that works well and you can take pride in.

Ray W




 
Droff 
Forum Newbie
Posts: 42

Age: 55
Loc: Choctaw, OK
Reg: 05-28-15
09-19-16 09:25 AM - Post#2652150    
    In response to 0utlaw

I spoke with the owner, he told me 11.5:1 compression and he's ran it on 91 octane. The heads are square port, 72cc with straight plugs and 220cc runners. It is still in his truck, which he races, mud I think, and he has 8-9 passes on the engine. He said the cam is pretty lumpy, which I kind of guessed but I will be able to hear it run. He's selling as he wants to go BB.

I'm not necessarily looking for just HP, actually more interested in the TQ and a 383 will get me the TQ to get the car moving, just not sure if this 383 would be an option. I would say I'm looking more for more low end TQ, not high end.

I had checked on those possible oil leak locations and didn't find anything. Old eyes don't help but I ended up with clean fingers when I checked.



 
66cayne 
Valued Contributor
Posts: 2734

Reg: 08-06-08
09-19-16 09:40 AM - Post#2652153    
    In response to Droff

that engine sounds a little beastly. With that much compression and cam lift and running it on 91 octane it must have .050 duration numbers in the .245-.250 range. NOT a street friendly combination. At least what most people consider friendly. You are going to need a loose converter and low rear gears to get it moving.



 
Droff 
Forum Newbie
Posts: 42

Age: 55
Loc: Choctaw, OK
Reg: 05-28-15
09-19-16 10:24 AM - Post#2652160    
    In response to 66cayne

Beastly is kind of what I was thinking but how tame can you make it with a cam swap?



 
LUVmachine 
Frequent Contributor
Posts: 1453

Age: 36
Loc: Redding Ca
Reg: 10-02-14
09-19-16 10:49 AM - Post#2652164    
    In response to Droff

I still think those big intake runners are going to kill your low rpm torque. Even with a small cam change I don't think think it will be good and probably boost your dynamic compression ratio over pump gas friendly levels.

71 Chevelle BBC powered
71 C-10 454 with weiand 177 (SOLD)
72 406 sbc powered Chevy LUV sleeper (SOLD)
2010 GMC Sierra crew cab 4X4
http://s626.photobucket.com/user/GJohnson81/libra r...


 
66cayne 
Valued Contributor
Posts: 2734

Reg: 08-06-08
09-19-16 12:53 PM - Post#2652184    
    In response to LUVmachine

I will throw my hat in to that ring. To many changes to get it where you would want it.



 
LUVmachine 
Frequent Contributor
Posts: 1453

Age: 36
Loc: Redding Ca
Reg: 10-02-14
09-19-16 01:02 PM - Post#2652187    
    In response to 66cayne

I think the idea using a 350 with the vortec heads would be the best fit for the goal a nice RV type cam with a little more lift and duration than stock would be nice. If you have all those parts already minus the carb and cam you are almost there. Lumpy cams with poor street manners are way overrated. How much time do spend at idle anyway? I've been there and done that and it always resulted in disappointment.

71 Chevelle BBC powered
71 C-10 454 with weiand 177 (SOLD)
72 406 sbc powered Chevy LUV sleeper (SOLD)
2010 GMC Sierra crew cab 4X4
http://s626.photobucket.com/user/GJohnson81/libra r...


 
Droff 
Forum Newbie
Posts: 42

Age: 55
Loc: Choctaw, OK
Reg: 05-28-15
09-19-16 03:06 PM - Post#2652209    
    In response to LUVmachine

Right now, I don't have anything for either engine, just a couple stock 350's.

Trying to keep costs reasonable while trying to get some more HP and TQ is what brought the vortec add-ons into the mix. I'd need all those parts - heads, intake, carb and cam and the misc parts to go with those.

That's pushing $1K pretty easy, that's why that $1500 383 caught my eye but without different heads and a different cam, I'd kind of agree with LUV, not sure I'd like driving it around town all that much.



 
japete92 
"4th Year" Silver Supporting Member
Posts: 968
japete92
Loc: No. Virginia
Reg: 01-18-13
09-19-16 04:15 PM - Post#2652225    
    In response to Droff

Does at least one of your two 'stock' 350's NOT need rebuilding?

If so, perhaps getting it (the one NOT needing rebuilding) in proper operating condition/tune and driving the car will satisfy you. Allow your 'seat of the pants' to be the judge.

If you want 'more', as others have suggested, a 'mild 383' (one with its highest torque in the approx 1500 to 3500 rpm range) would be a nice place to be on a street car. Perhaps one can be built from one of your 350s while still leaving you a 'driver'?

You will need dual exhaust (if you don't already have it). Headers? I'm not a fan of headers on a street car.





 
Droff 
Forum Newbie
Posts: 42

Age: 55
Loc: Choctaw, OK
Reg: 05-28-15
09-19-16 04:58 PM - Post#2652234    
    In response to japete92

  • japete92 Said:
Does at least one of your two 'stock' 350's NOT need rebuilding?
If so, perhaps getting it (the one NOT needing rebuilding) in proper operating condition/tune and driving the car will satisfy you.


One could be driven without rebuilding, it would need a few things to get it going, but well under $1K (without knowing for sure)

  • japete92 Said:
Perhaps one can be built from one of your 350s while still leaving you a 'driver'?



That's been on my mind as well, just much longer getting to a 383 that way. But the car should be on the road....

No headers?




 
japete92 
"4th Year" Silver Supporting Member
Posts: 968
japete92
Loc: No. Virginia
Reg: 01-18-13
09-19-16 06:28 PM - Post#2652260    
    In response to Droff

Headers provide the most benefits in the higher rpm ranges. How you intend to drive on the 'street' will determine how much time you will spend in those higher rpm. Build a 383 for low rpm torque and you will not need to rev high to produce acceleration.

Headers may cause ground clearance problems, under hood heat problems, starter problems, and noise problems (you'll need a free flowing exhaust downstream of the collectors which may be objectionably noisy).

It's a matter of priorities. My opinion? On a 'street' car, 'manners' and 'drivability' have priority over ultimate performance.

Your priorities are the ONLY ones important for your car.



 
LUVmachine 
Frequent Contributor
Posts: 1453

Age: 36
Loc: Redding Ca
Reg: 10-02-14
09-19-16 08:33 PM - Post#2652292    
    In response to japete92

I guess I misread what you posted earlier I thought you had a set of rebuilt vortec heads and only needed a cam and carburetor. I would run what I had the best 350 you have that needs minimal work. Leave it stock or use the best of what you have for now. Pick a plan for the other one and stick to it and collect the parts on the list until you have what you need. This way you set a goal and have a good plan in advance if you stick to the well thought out plan you will save time and money.

If you go with a 383 get the block machined up and start with a rotating assembly. Check with your machinist he may be able to save you money if you buy parts through him. Who knows maybe he has what you need in his shop that someone else ran out of money and never picked up. Just do your research and don't have him recondition anything that you can buy new for less money. The machinist I use will sell me the same parts I would buy anyplace like summit but his cost is usually cheaper.

Vortec heads have their limits I personally wouldn't put them on a 383. In your case a very mild low rpm torque monster they might work well and if I could find a set ready to run for the right price I might go with them. I would probably be more into them if I could get a decent intake manifold for a steal.

Take a stock 350 in decent shape upgrade the cam,intake carb and exhaust and you will pick up a noticeable performance increase. Just don't over do it. Everything has to work together as a package and it isn't just the motor. Everything from gear ratio, stall speed, weight of the vehicle, tire size, intended use,etc all have to work together or you will be disappointed.

71 Chevelle BBC powered
71 C-10 454 with weiand 177 (SOLD)
72 406 sbc powered Chevy LUV sleeper (SOLD)
2010 GMC Sierra crew cab 4X4
http://s626.photobucket.com/user/GJohnson81/libra r...


 
spicetraders 
Forum Newbie
Posts: 6

Reg: 03-26-14
11-23-17 06:35 AM - Post#2715440    
    In response to Droff

For any older 350 they are great engine for rebuild and full of so many options for modifications for HP.

But one has two very simple places to start on your engine before making any choice.
First is it a four bolt main
If so take the block apart and have it cleaned spotless (hot tank) at best shop in town and then have then Magnaflux it for cracks.
If no cracks then go for the rebuild you will save money and end up with what you want. (I cut my cost in about half over decked out crate)

I had to looked at three blocks before I found a non-cracked solid block. But then I gave it to a local race engine builder to machine it to make my 383 stroker. He was also a wealth of info on which was the better type and make of crank and cam for my needs.


yup







If you have nothing constructive to add then why just be a teapot?


Edited by spicetraders on 11-23-17 06:37 AM. Reason for edit: No reason given.

 
Raven18940 
Member
Posts: 450

Reg: 09-22-04
12-10-17 06:34 AM - Post#2717468    
    In response to spicetraders

I have a used block sitting in my garage and personally I haven't been able to see the value in rebuilding. This crate engine keeps shooting down every spreadsheet I make to rebuild my block.

https://www.summitracing.com/parts/nal-12530283/ov ...

Features:
-4 bolt mains
-Vortec heads
-Hypereutectic pistons
-Low friction 1.5mm ring pack
-Late model powdered metal rods
-Factory roller cam
-9.4:1 compression
-NEW block, not a "hand selected core", fresh and thick cylinder walls.

Then slot in a SP 357 cam

https://www.summitracing.com/parts/nal-12677151

215/223 .473/.473

Now you have a 350hp/405tq long block 350 $2400.



 




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