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350 build up opinions?

4K views 17 replies 11 participants last post by  75gmck25 
#1 ·
Ok, so I want to build a 350, going to be a daily driver, but I still want to at least get to the 1hp for 1ci. This is a post from a monte carlo site, after getting some help from one of the guys there, just wanted to see what everyone here thought..

"
So say, I have a 350.
Do basicaly everything Monte12345 said.

350 block, getting all the things done to it:
-Crank and Cam centerlines aligne bored
-Decks milled to be square with crank centerline
-Blocked bored and honed with deck plates. (30 over prob)
-Crank reconditioned
(Anything else that would need to be done? And any idea what this should cost, roughly)

I get a set of 6inch rods.
(BTW, why 6 inch? Arent stock rods a little shorter?)
(6 inch rods where suggested to me, not sure why, never got an answer, can anyone explain?)

My dished Hyper pistons, whatever one the speed shop suggests after seeing the rest of my build to get around a 9.5:1 CR

Vortec heads
A vortec edlebrock rpm intake
Edlebrock carb. (750 or 600 or what?? Not sure which is better for my build, assume the 750? Will either choice affect MPG?)

Set of 1.5:1 roller rockers

Powermax 2040 cam. 210/216@.50 .440/.454 lift.
(Can someone please explain what those two sets of numbers are? specifically the left/right numers of each pair, not what the pair represents)

How many hp/ft lb tq do you think this engine would give me?


-----------------------------------------
Also, i'll be doing the exhaust once the engine is in the car, what set of headers should I get?
Prob going to do a true duel 2 1/4 straight back.
"

Thanks alot
-Steve-
 
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#2 ·
The numbers on the left and the right of the cam profile represent intake(on the left) and exhaust(on the right). Some one correct me if im wrong :welcome:

I would run the 750 on your combo and call it good. Virtual Engine Dyno says 350hp and 300ft/lb tq.

To get your compression to 9.5:1 youll need a -12cc dish assuming your heads are 64cc chamber Vortecs.

Im not sure why your being recomended the 6in rods, just use your stock 5.7s and youll be fine. Can someone chime in and maybe explain this if there is an explination?
 
#3 ·
only one explanation for 6" rods.

it has to do with the physics of power to the crank from the piston. having more leverage lets the bearing load ease up a bit but not much. from what i`ve heard and read 6 " rods are a waste of money B/c you have to buy special pistons to use 6" rods. not much power increase though i might say. but hey i ain`t gonna rock your boat. :thumbup: scott.




p.s. i wouldn`t use 6" rods unless i had a deep pocket and was gonna use the car for race only.
 
#5 ·
Thanks guys, I went to that link, and found a build for 400hp and 420 ft lbs of torque, which is better for me. :D

Discplacement- 355ci 4.030 x 3.480
Compression- 9.0:1 with Iron heads. (Doesnt say what pistons, so which would I need?

Heads- GMPP Vortec Iron 2.02/1.60(These I have to get done? They come with smaller valve lifts correct? And what does GMPP stand for?)

Cam- Comp Cams Xtreme 262, PN 12-238-2
218/224@ 0.050 .462/.468 110 degrees l.s (What is the degrees for?)

Intake- edelbrock Performer RPM, PN 7101
Carb- ~~Edelbrock 600 CFM performer, PN 1400 OR
~~ Holley 600 CFM Vacuum secondary, PN 0-1850

Headers- 1 5/8 inch long tube headers. Suggests Hedmen, holley, or dynomax.
This is with 2 1/2 in exhaust with mufflers.

Questions, -what type of pistons will I need to get desired CR?
-The Vortec heads are the same ones I will get if I go to my GM dealer and order Vortec heads?
-Is the cam daily driver friendly?
-Which carb is better?
-What brand headers should I get?
-Aside from pistons, stock bottom end is ok to use? (Crank, rods, things like that)

Thanks alot guys
 
#7 ·
74chevyflat said:
it has to do with the physics of power to the crank from the piston. having more leverage lets the bearing load ease up a bit but not much. from what i`ve heard and read 6 " rods are a waste of money B/c you have to buy special pistons to use 6" rods. not much power increase though i might say. but hey i ain`t gonna rock your boat. :thumbup: scott.
p.s. i wouldn`t use 6" rods unless i had a deep pocket and was gonna use the car for race only.
How does a 6" rod get more leverage on the crank than a 5.7" rod at any angle that counts?
 
#8 ·
it also has to do with the acceleration of the piston from top dead center and bottom dead center. it also allows the piston to remain at tdc for a fraction longer giving it more of the effect of the combustion cycle.
or at least thats how it has been explained to me.
 
#9 ·
Ok thanks everyone, good to know I can use the stock rods.
And thanks mustangsaly, gotta look through all of those, see which is the one I need to buy to suit that build.

Does anyone have any opinions on the build, as far as it being good/bad for a daily during the nice months. Or what type of pistons I will need to get the suggested 9.0:1 compression ratio?

Thanks
 
#10 ·
Artemis Entreri said:
Thanks guys, I went to that link, and found a build for 400hp and 420 ft lbs of torque, which is better for me. :D

Discplacement- 355ci 4.030 x 3.480
Compression- 9.0:1 with Iron heads. (Doesnt say what pistons, so which would I need?

Heads- GMPP Vortec Iron 2.02/1.60(These I have to get done? They come with smaller valve lifts correct? And what does GMPP stand for?)

Cam- Comp Cams Xtreme 262, PN 12-238-2
218/224@ 0.050 .462/.468 110 degrees l.s (What is the degrees for?)

Intake- edelbrock Performer RPM, PN 7101
Carb- ~~Edelbrock 600 CFM performer, PN 1400 OR
~~ Holley 600 CFM Vacuum secondary, PN 0-1850

Headers- 1 5/8 inch long tube headers. Suggests Hedmen, holley, or dynomax.
This is with 2 1/2 in exhaust with mufflers.

Questions, -what type of pistons will I need to get desired CR?
-The Vortec heads are the same ones I will get if I go to my GM dealer and order Vortec heads?
-Is the cam daily driver friendly?
-Which carb is better?
-What brand headers should I get?
-Aside from pistons, stock bottom end is ok to use? (Crank, rods, things like that)

Thanks alot guys
For 9:1 compression, use an 18cc dished piston like a KB142 and use a .040" quench height.
http://kb-silvolite.com/performance.php?action=details&P_id=154

Some Vortec heads are modified to increase the potential valve lift and valve size. For a mild daily driver motor, you might not notice the difference.

The cam will be very DD friendly, with good midrange power.

Carbs are very subjective parts, some have good luck with one brand, some with another. If you aren't an experienced carb guy, seek local help in this area.

The right headers for your application won't exist on the shelf. I would take a set of 1-5/8" primaries and extend the length to 45" or so and use a 2-1/2" collector into a 2-1/2" system. There's a lot of torque to be gained in the exhaust system.

A stock bottom end should work just fine, use good rod bolts. I would use a good oil pan with a windage tray and scraper.
 
#11 ·
Unless the block has a spun main bearing it doesn`t need align honed, not only that align honing it will not increase power any.
I also wouldn`t get it decked down to 9.00, all I did to my block was have it decked .010 and used a GM .028 thick head gasket that gave me a a Quench distance of .043. Why I don`t like the idea of decking it down to 9.00 is since I like to have a little leeway in case the block ever needs to be decked again, you can remove material, but you can`t put it back. If it were me I would find a 880 block so I could use a roller cam with the factory components. It also comes stock with a windage tray. This is the exact thing I did on my build up. If you follow this route, make sure you use the cloyes street roller Vortec timing chain. If you use Vortec heads the stock 1.94 1.50 valves will work fine for a daily driver and making 1 horse per cubic inch. You can order a heavy casted set from RHS as I did ready to assemble for around $450. This way you eliminate the worry of the factory light casted jobs that crack the first time you run them hot. Lastly make sure you set the timing low, vortec chambers with tight quench is real efficient, it doesn`t need alot of advance to make power.
 
#14 ·
DoubleVision said:
Unless the block has a spun main bearing it doesn`t need align honed, not only that align honing it will not increase power any.
I also wouldn`t get it decked down to 9.00, all I did to my block was have it decked .010 and used a GM .028 thick head gasket that gave me a a Quench distance of .043. Why I don`t like the idea of decking it down to 9.00 is since I like to have a little leeway in case the block ever needs to be decked again, you can remove material, but you can`t put it back. If it were me I would find a 880 block so I could use a roller cam with the factory components. It also comes stock with a windage tray. This is the exact thing I did on my build up. If you follow this route, make sure you use the cloyes street roller Vortec timing chain. If you use Vortec heads the stock 1.94 1.50 valves will work fine for a daily driver and making 1 horse per cubic inch. You can order a heavy casted set from RHS as I did ready to assemble for around $450. This way you eliminate the worry of the factory light casted jobs that crack the first time you run them hot. Lastly make sure you set the timing low, vortec chambers with tight quench is real efficient, it doesn`t need alot of advance to make power.
May i ask where you got those RHS heads from?
 
#16 ·
Thanks alot everyone, would of replied to all the responses faster, but i've been laid up in bed, I hate migraines. Almost 3 days of wanting my head to just explode and get it over with, lol. I couldn't see or move, quite pleasent.

I guess the only questions i have left, are things that should be done to the block, which I have to get my hands on a block first to see what kind of shape its in, so I will be back once I actually have an engine to start building up on.

Thanks alot everyone.
 
#18 ·
The specs on that cam are actually not that aggressive, depending on what vehicle and transmission you have. Its good for a daily driver, but you could probably go with a little more lift if you have a relatively light vehicle and a high stall torque converter.

GMPP parts can be ordered from just about any GM dealer, so shop around for price. You might find a local dealer that will match the mail-order price.

If you want a real simple solution, order the GMPP 330 hp Vortec 350 and use that as a starting point. Its not quite 1 hp/cu in, but you can order the entire engine from GM as one assembly with a 12/12 GM warranty.

Most folks buy the GMPP engines (which are a long block with tin - valve covers and oil pan) and add the manifold, carb and external items (water pump, fuel pump, headers, etc.), but Pace and other dealers also sell that engine as a complete unit with all accessories. If you are willing to spend the money you can get a complete engine that you can just drop in to your vehicle.

Bruce
 
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