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  #1  
Old Dec 14th, 08, 12:48 PM
nikwho nikwho is offline
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Default Building my 350. how do i build torque?

So, my 350 is sitting in the machine shop after getting some machine work done. Its a 69' block and must not of had much miles on it at all because my machinist told me that its well within tolerances to run standard bore. I really am on a budget so i want to keep the standard bore because i have a set of Kieth black hyperutectic domed pistons that my machinist says will probably run about 10.5-11:1 compression with the double hump 64cc heads. 2.02/1.60 valves with 1.5 crane roller rocker arms, pinned pressed in rocker arm studs. He tells me that the high compression will work on pump gas being that i live at 7000 feet ASL. im running an eagle forged crank and new cam, crank and rod bearings. I have a holley 650 carb. im not sure of the model number on the carb. edelbrock intake with RPM stamped on it. So, i have most of the parts and the engine came with an Erson cam from the guy that i bought it from. but the lifters were not kept track of what was where so im not sure if i can just run that cam with new lifters and see how it runs or if it will flatten out and potentially damage the engine???? If i need to run a new cam kit, I would like to get this engine to pull out as much torque as possible. Im absolutely retarded when it comes to cams so i need help to choose one.
A little back story of why i have a complete engine that is all taken apart is the guy that i bought it from spun a bearing on the forged crank that was previously in the engine. he had bought another crank off of craigs list that was supposed to be a 350 crank but turned out to be a 327 crank that the guy did not confirm. so, with 350 pistons and rods the engine did not run too great with a 327 crank. He took the engine all apart and sold it to me before he ever found out the crank was wrong. he has more money than time i guess and ended up buying a crate motor. so, im just trying to figure out what to do to get the most i can on a limited budget out of this engine. thanks, Nik
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  #2  
Old Dec 14th, 08, 01:42 PM
62nova406 62nova406 is offline
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Default Re: Building my 350. how do i build torque?

11 to 1 with steel heads and pump gas?? you gonna need a cam with some decent duration to bleed off a little compression. witch is going to need more stall converter and steep gears. what do you have for the rest of your combo? trans and gears . is this a street car? im sure some pro's will chime in here.
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  #3  
Old Dec 14th, 08, 03:27 PM
Big Dave Big Dave is online now
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by nikwho View Post
I really am on a budget so i want to keep the standard bore because i have a set of Kieth black hyperutectic domed pistons that my machinist says will probably run about 10.5-11:1 compression with the double hump 64cc heads.
Quote:
Originally Posted by nikwho View Post

2.02/1.60 valves with 1.5 crane roller rocker arms, pinned pressed in rocker arm studs.

He tells me that the high compression will work on pump gas being that i live at 7000 feet ASL.


I have to agree that is a lot of compression for pump gas even at your altitude. You will need to kill some of it some how. Shaving the piston domes lightens the load as does deeper valve pockets for added lift.

Quote:
Originally Posted by nikwho View Post
I'm running an eagle forged crank and new cam, crank and rod bearings.


I am assuming you bought a 3.48" stroke crank to match your 350 pistons. You didn't mention what you got for your new cam.

Quote:
Originally Posted by nikwho View Post
I have a holley 650 carb. im not sure of the model number on the carb. edelbrock intake with RPM stamped on it. So, i have most of the parts and the engine came with an Erson cam from the guy that i bought it from. but the lifters were not kept track of what was where so im not sure if i can just run that cam with new lifters and see how it runs or if it will flatten out and potentially damage the engine????


Yes the old cam will not last long with mixed lifters; it will last longer reusing the old lifters, even on the wrong lobes, than it will with brand new totally flat bottomed lifters. I personally recommend new lifters and a new cam to answer your desire for more torque.

Quote:
Originally Posted by nikwho View Post
If i need to run a new cam kit, I would like to get this engine to pull out as much torque as possible. Im absolutely retarded when it comes to cams so i need help to choose one.


The sooner you can close the intake valve the more torque you will build. This is why a long duration cam will bleed off excess compression, a motor will not make power with the valves open. It effectively shortens your stroke by closing the intake valve later in time after the piston has already started up the bore. In essence it converts your 350 back into a 327, which is why torque suffers with long duration cams.

So what do you want to make torque? A short duration cam with a lot of lift (aggressive lobes). This is a problem with flat tappet cams, as the edges dig into the flank of the cam lobe rather than riding it up after a certain point. But you did say you were on a tight budget, and you had a 1969 block, so retro-fit hydraulic or solid roller lifters are out. You can not use 1986-'94 hydraulic rollers because you have a one piece rear main seal crank (trading a date coded 1969 327-350 block for a new 350 block is easy everyone wants your block a lot more than they want a common one piece 350 block).

That leaves looking through the cam catalog for a RV cam (standard stump puller), or a short track circle race cam that builds a lot of torque for excellent street manners.

I checked CompCams Catalog (The only company gracious enough to give me a paper catalog to look stuff up on; or I could be able to recommend another grind from a different vendor if they were to actually mail me one) and found five potential grinds I think would work well to build torque in a street car. They are:

Grind_______Cam_____Duration_______Valve
Number____Number___@0.05"Lift______Lift__________L SA
12-242-2__XE268H____224°/230°____0.477"/0.480"___ 110°
12-239-3__X4262H____218°/226°____0.462"/0.480"___ 111°
12-209-2__275DEH____219°/229°____0.462"/0.482"___ 110°
12-671-4__N+L79H____228°/236°____0.468"/0.462"___ 112°
12-211-2____280H____230°/230°____0.480"/0.480"___ 110°

Big Dave
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Old Dec 14th, 08, 06:08 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

OK, Big dave, yes it is a new crank to match the pistons. I meant that all of the bearings have been replaced, including the cam bearings. I have not bought a new cam. I can give the number to erson and they will tell me the grind if i should be considering trying that cam. although, if it will last longer and get the results i want, i would rather spend a couple hundred and get a new cam. I have a powerglide that has been gone through with some after market parts. I recieved, with the car upon purchase, an eleven hundred dollar reciept from a drag shop in LA. I was thinking that it could be bull**** but the guy forgot about it until after the sale was final so i do not think that it was a ploy to sell the car. the reciept is dated year 2000. Im not hardset to run this tranny but i have it and its free. If needed, ill buy a th350 from a friend at work. As far as the gear ratio goes, its yet to be determined. this is a ground up restoration so i will be replacing the stock rear end. i have a ford 9" out of an F150 that would need to be shortened as well as a GM 12 bolt that i believe is out of a 55 chevy p/u. not sure on the year. I am leaning toward the 12 bolt because its a GM unit and i also have an eaton posi that I can rebuild and put in it. I said im on a budget. Im trying to save where i can and im not skimping where its important. Im not interested in just building the engine... I do not know where i will ultimately go engine wise. I may use another block that i have to build a small block stroker or i may get greedy and decide to some day build up a big block for it. I have this engine and its nearly complete so I want to build it up well and run it in the nova untill i get bored with it. I have a couple of other project to use this engine for when its time is up in the nova. I also recieved with the car a 2500 stall converter(im told). who knows if it really is. If needed, i will buy a new converter to the specs that will work best with the car. Also, i know that the machinist that i am working with is very knowlegable. He just looked at the pistons and heads and said that it may be that high.... im not sure if he is certain, but he seemed very confident.
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  #5  
Old Dec 14th, 08, 06:12 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by 62nova406 View Post
11 to 1 with steel heads and pump gas?? you gonna need a cam with some decent duration to bleed off a little compression. witch is going to need more stall converter and steep gears. what do you have for the rest of your combo? trans and gears . is this a street car? im sure some pro's will chime in here.

powerglide with gear ratio yet to be determined. That will be another question that i hit you guys up with when that time comes yes, it is pretty much going to be a steet car that i would love to take to the strip for kicks from time to time, maybe a few times a year realistically(firebird raceway is a tad over two hours away). its just going to be a weekend warrior, not a daily driver.
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  #6  
Old Dec 14th, 08, 06:16 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

i may be very incorrect in assuming that a 55' chevy half ton p/u would more than likely have something in the neighborhood of 3.73 or 4.11 gears in it???? if i could skate with whats in there now(which is not origional), i would like to. just in the name of trying to save a little scratch.
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Old Dec 14th, 08, 06:35 PM
Big Dave Big Dave is online now
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by nikwho View Post
i may be very incorrect in assuming that a 55' chevy half ton p/u would more than likely have something in the neighborhood of 3.73 or 4.11 gears in it???? if i could skate with whats in there now(which is not origional), i would like to. just in the name of trying to save a little scratch.
1955 pick up had a Salisbury drop out pumpkin style rear end under it from the factory, not a 12 bolt (the Spicer 12 bolt didn't come out until 1965). As to what gears are in the 12 bolt pop the inspection cover and count teeth. It will also tell you if you have a posi or not by looking for springs inside the differential. A 12 bolt is much better than any nine inch you can find.

Big Dave
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Old Dec 14th, 08, 06:50 PM
71SS454 71SS454 is offline
 
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Default Re: Building my 350. how do i build torque?

But you have to find out if you have a truck 12 bolt or a car 12 bolt. The two are different and internal parts are not the same. The car rear end is stronger. The powerglide can work fine, but you're going to need more gearing. A TH350 would be a much better choice, then you could run something like a 3.55/3.73 gear and still have some higway manners.

You're going to need to get the compression down.Keith black lists their flat top pistons as making 10.3 compression with a 64cc head. This would probably work out to more like 10:1 in your engine and would be much better, even at 7000ft. This is just like the cam, buy a new one. It gets expensive, but it's better to do it right the first time than to do it twice. Just think, what if you decide to drive to somewhere with lower elevation? Then you're in trouble with really high compression.
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Old Dec 14th, 08, 06:53 PM
Big Dave Big Dave is online now
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by nikwho View Post
OK, Big dave, yes it is a new crank to match the pistons. I meant that all of the bearings have been replaced, including the cam bearings. I have not bought a new cam. I can give the number to erson and they will tell me the grind if i should be considering trying that cam. although, if it will last longer and get the results i want, i would rather spend a couple hundred and get a new cam. I have a powerglide that has been gone through with some after market parts. I recieved, with the car upon purchase, an eleven hundred dollar reciept from a drag shop in LA. I was thinking that it could be bull**** but the guy forgot about it until after the sale was final so i do not think that it was a ploy to sell the car. the reciept is dated year 2000. Im not hardset to run this tranny but i have it and its free. If needed, ill buy a th350 from a friend at work. As far as the gear ratio goes, its yet to be determined. this is a ground up restoration so i will be replacing the stock rear end. i have a ford 9" out of an F150 that would need to be shortened as well as a GM 12 bolt that i believe is out of a 55 chevy p/u. not sure on the year. I am leaning toward the 12 bolt because its a GM unit and i also have an eaton posi that I can rebuild and put in it. I said im on a budget. Im trying to save where i can and im not skimping where its important. Im not interested in just building the engine... I do not know where i will ultimately go engine wise. I may use another block that i have to build a small block stroker or i may get greedy and decide to some day build up a big block for it. I have this engine and its nearly complete so I want to build it up well and run it in the nova untill i get bored with it. I have a couple of other project to use this engine for when its time is up in the nova. I also recieved with the car a 2500 stall converter(im told). who knows if it really is. If needed, i will buy a new converter to the specs that will work best with the car. Also, i know that the machinist that i am working with is very knowlegable. He just looked at the pistons and heads and said that it may be that high.... im not sure if he is certain, but he seemed very confident.
As to building torque the longer the stroke the more torque you build because as I said earlier, an engine doesn't start making power until the intake valve closes and starts the compression cycle. If the valve is closed and the piston is traveling a long distance to get to the top of the bore it is building compression all the while, which builds power. With a later closing valve due to a lot of duration then your true displacement shrinks as the engine doesn't start the compression cycle until the valve closes.
If you can find a 1986-'94 350 block one piece rear main seal block then it will have hydraulic roller lifters which allow you to get eight additional degrees of valve duration without any penalty as the lifter hits at only one point instead of wandering back and forth over the lobe like a flat tappet does. It also allows you to run a more aggressive lobe profile with faster opening valves without the fear of the lifter colliding with the ramp. Add in a longer stroke such as a 3.750"-3.800" crank and you are building more torque than the 350 with the 3.48" stroke.
You have to replace the pistons when you change the length of the stroke (like the last owner discovered with his pistons down over a quarter inch in the bores). If you buy a longer rod along with the longer stroke you get lighter pistons allowing you to rev more quickly.
Your "built" Powerglide may be of more interest to a racer than a street car. It depends upon the level of parts inside and whether it needs going through again (seals dry out over time). If you are looking for a cruiser with only occasional strip duty an overdrive transmission makes much more sense.

Big Dave
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Old Dec 14th, 08, 09:28 PM
62nova406 62nova406 is offline
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by nikwho View Post
powerglide with gear ratio yet to be determined. That will be another question that i hit you guys up with when that time comes yes, it is pretty much going to be a steet car that i would love to take to the strip for kicks from time to time, maybe a few times a year realistically(firebird raceway is a tad over two hours away). its just going to be a weekend warrior, not a daily driver.

just keep in mind your converter and cam combo are crucial.....and the duration has to match stall speed. trans specialties has good solid converters on the cheap ive run their tight ten in. 2800 stall .......it was perfect for 237* at .05 duration.
__________________
" IMAGINE THAT "

62 nova 406 sbc
456 gears 5500 stall powerglide
6.80's in the 1/8 th
street driven




slide show http://s470.photobucket.com/albums/r...view=slideshow

vid http://www.youtube.com/watch?v=DoocV93k1Fg
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  #11  
Old Dec 19th, 08, 12:52 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

Yeah, i have a co-worker that has been building cars for years and says that he has a pretty stout th350 that he would sell to me. says it was gone through this past summer with new seals and a shift kit. has not run since. wants $400 for it. maybe i could get close to that out of my glide. I will be buying a new torque converter either way so i can match that to the new cam. so, i can make them compliment each other. so, a more radical cam would bleed off compression and a higher stall converter would help? i just dont want to make the car unpleasant to drive. im still not sure how the stall converter works, does it not engage the transmission until the rpm that it is rated? so, with a 2800 rpm converter would the car not move until the engine hits 2800 rpm?? sorry, im trying to absorb as much as i can and learn quickly so i make good choices for my car. thanks a bunch guys! Nik
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Old Dec 19th, 08, 01:50 PM
Big Dave Big Dave is online now
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Default Re: Building my 350. how do i build torque?

Well yes sort of.

It slips like a bad automatic transmission with worn out clutches slips but it is still moving the car forward. It just doesn't fully engage (flash) until it reaches it's designed RPM. Just like slipping a clutch, it builds up heat in the converter until it reaches it's flash point so you will need a large oil cooler for the converter to put in front of your radiator.

Going back to an earlier post on the 12 bolt rear end. The truck 12 bolt used a 10 bolt pinion size so your available gear choices are smaller compared to those for a car. Also the axel bearings are larger to support a pick-up truck and it's load so you have different axels as well (usually with a five on five inch bolt circle instead of the car size of five on 4-3/4 inch). Once again you have to look inside to see what you have as to ratios and which type of posi if any. The truck posi will break on pavement as it relies upon a cast iron claw to engage a gear at speed (ratchet and pawl) which isn't designed for the shock of big tires and pavement, and it also has a bigger hole in the differential to get the parts in which weakens the carrier. The truck twelve bolt has a smaller diameter pinion shaft of 1.438", while the car uses a 1.626" dia. pinion.

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Old Dec 19th, 08, 07:07 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

k. got it. I need to ask my buddy what the axle came out of. i know it is not the factory unit. he has a pro truck(off road race truck) and has a few really built up 9" rear ends sitting in his shop so i see his desire to utilize that unit. he said today that he will give it to me. im trying to figure out if the eaton posi that i have will fit into it and if any local shop will cut it down or if that is a project that can be taken on by a shadetree mech. like myself. Im not interested in cutting corners but im trying to stretch my dollars as far as I can and do as much of the work myself as i can get away with....
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Old Dec 19th, 08, 09:20 PM
Big Dave Big Dave is online now
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Default Re: Building my 350. how do i build torque?

The Eaton posi will interchange between the truck 12 bolt and a car 12 bolt, the gears won't. Aside from the smaller pinion and limited selection of gears the truck 12 bolt can be used on the street without a problem. You run a risk of breaking the pinion if you hammer it with a lot of power and have some good traction as it will be the weakest link in the rear end.

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Old Dec 20th, 08, 03:26 PM
nikwho nikwho is offline
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Default Re: Building my 350. how do i build torque?

Quote:
Originally Posted by Big Dave View Post

Grind_______Cam_____Duration_______Valve
Number____Number___@0.05"Lift______Lift__________L SA
12-242-2__XE268H____224/230____0.477"/0.480"___ 110
12-239-3__X4262H____218/226____0.462"/0.480"___ 111
12-209-2__275DEH____219/229____0.462"/0.482"___ 110
12-671-4__N+L79H____228/236____0.468"/0.462"___ 112
12-211-2____280H____230/230____0.480"/0.480"___ 110

Big Dave
So, how do I go about narrowing down these cams? I have decided to go ahead with the Th350 tranny from my buddy. its got a tci kit and a 2800 rpm converter. I dont think that a powerglide is going to yeild the most street friendly driving characteristics. So, the only other specs that i can think of is that im running a gear drive and Im pretty sure that i will buy a flat tappet cam kit to save a little money. so, however that will change what cam will work with ramp angles and what not. im sure that i will not be driving the car outside of town so im not worried about driving at lower elevations. when i take it down to the track, it will be trailered and can run on race gas or a mix of 92 and race gas.
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