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Topic Review (Newest First)
12-27-2018 09:08 AM
Duker Digers So I like to give thanks all the inputs on the motor build up. Oh by the way the intake I have are the non air gap RPM type divided for better torque curve. I heard they perform better in cold weather (40-60 deg.) with less problems.
Duker
12-25-2018 08:36 AM
Duker Digers Ok I can do that, but I have a Holly TBI and its adjustable on the fly too. I am eager to try it. So it can hidden under the air cleaner and not munch wires to deal with, just a frame electric fuel pump or I can use the ( fuel pump in the tank and return fuel lines ) I have now on the newer frame. My main concern is the cam duration and piston matching. I need to find the H-power/torque rating of the cam I have new in stock. If I wanted a lot of H-power/torque I just install a BB mopar motor.
12-25-2018 05:31 AM
cerial Yes I seen you were transplanting it. Instead of building a carburated 383 or 400 with speciality parts you could grab a tbi donor truck to have everything to keep things simple with a mild rebuild on the drivetrain.
Tbi tucks under a aircleaner nice leaving the rest to look old. It gives nice drive ablity in all conditions while only requiring little investment of additional time.
While a carb might be nice for general driving. If you plan for elevation changes you should plan for swapping out jets a few times along your trip also.
12-24-2018 09:00 AM
Duker Digers Hi Cerial, A NOTE IN MY POST, ( the tow truck is gone ) so the motors in question are going into my 1942 street rod truck ....thanks for your input, going with a 350 /700R trans depends upon r end gear, and 400ci SBC
12-23-2018 10:42 PM
cerial Get a 88-93 rusted out Chevy with a tbi 5.7, 2wd 700r4, and 3.42 or 3.55 8.5 out back for around $800.

Pull the harness, ecm, axle and transplant them in the truck loosely. Or run a standalone ecm. 88-93 have a small cap HEI design which makes them easier to fit then the large cap models.
Give the engine a rebuild with a 10 over bore and stay close to factory cam specs. Rebuild the 700 with a stage 1 kit. Replace the bearings, seals, and brake hardware all around. Just refresh things staying away from extremes.
Keep cold weather and junk 87 fuel in mind. Rebuild the throttle body with new sensors lines. Cap and rotor and such just keeping everything stock or slightly above so that it is happy.

Should be able to get 14-16 towing flat and around 8 on the aggressive hills/in town.
While those numbers may not sound amazing know that we are talking about a $400 engine(if you were buying the engine in a yard/list) with a $800-1000 rebuild that is fuel injected and won't give you jetting fits when your somewhere like halfway up a mountain in Pennsylvania. Thing also has a single serpentine belt with self tension so no belt squealing or adjusting.

These motors are simple with low compression to run on junk gas. Yet the torque around 280ft/lbs @2500 is where you need it for a truck. Mated to a 700r4 with 3.42 or 3.55 rear end the thing keeps the rpm and stress on the engine low allowing a simple rebuild to last you 150 to 250,000 miles with basic maintenance.

By buying the entire truck you get all the little things that add up like accessories and wiring. While it is a good idea to refresh and test these things. Your not starting from scratch buying everything bran new and figuring out how everything needs to be engineered to fit together the best way.

I have and still do 500 mile round trips over a 2 day weekend to go to an event(usually a big car show). Feel like going to Indianapolis, Chicago, Columbus or anything on a whim I will just go. I have had break downs from time to time. Being able to go into a parts store in any State and say you need parts for a 1990 Chevy 1500 and get the part you need that day to replace something basic like an alternator, starter, fan clutch, or front caliper that is sticking keeps the small problems from becoming big issues.

While it is nice to say you have 350hp under the hood and feel that power when you slap that skinny pedal down. For something made for long trips like your describing low horsepower, low stress, the ablity to drive it anywhere in any condition, and get parts for it anywhere works better in my book.
12-23-2018 08:02 AM
Duker Digers thanks for your input...I am trying to take care of all different way to go. 35 years ago you did not have many engine shops thinking on stroke of a motor, so many new tech ways to go now. Thanks Duker
12-22-2018 11:15 PM
ericnova72 Yeah, I've read the whole Isky thing on rod length. Good read. All his Tech Tips are a good read.

The longer rod is better for cylinder wall loading with the longer stroke of the 400 and 383 stroker, I think that's the main advantage rather than breathing and high rpm.
12-22-2018 10:48 PM
techinspector1
Quote:
Originally Posted by ericnova72 View Post
everyone today uses at least the 5.7" rod length when they do a build. Can't say that I blame them.
Here's a blurb from Iskenderian on Isky Tips 2005 that may interest you......

"In fact, this may surprise you, but I know of a gentleman who runs a 5.5" Rod in a 350 Small Block Chevy who makes more horsepower (we're talking top end here) than he would with a longer rod. Why? Because with a longer dwell time at BDC the short rod will actually allow you a slightly later intake closing point (about 1 or 2 degrees) in terms of crank angle, with the same piston rise in the cylinder. So in terms of the engines sensitivity to "reversion" with the shorter rod lengths you can run about 2-4 degrees more duration (1-2 degrees on both the opening & closing sides) without suffering this adverse affect! So much for the belief that longer rod's always enhance top end power!"
12-22-2018 10:33 PM
ericnova72 Techinspector, you raise a valid point. I had not realized that finding a stock rod length 400 piston had become such a rare animal. I found UEM/Silvo-Lite has just 1, a 5cc flat top in the claimer line with a 1.565" comp height, #9907HC.

There is just nothing with a big enough dish for pump gas, 400 SBC, and the short stock 400's 5.565" rod....everyone today uses at least the 5.7" rod length when they do a build.

Can't say that I blame them.
12-22-2018 10:08 PM
techinspector1 Follow this tutorial closely to insure a long life from your flat tappet cam and lifters......
https://www.crankshaftcoalition.com/...ips_and_tricks
12-22-2018 09:33 PM
techinspector1 You're making it difficult by not answering my questions, so I will assume the block deck height is 9.025".

You cannot use the original rods because nobody makes a piston for that rod length (5.565") anymore. You will need different pistons with dishes to keep the static compression ratio low enough to run pump gas without the motor detonating.

Because you have to use a longer rod, you will have to use a special rod that is clearanced at the big end to prevent the rods from crashing into several of the cam lobes and ruining the fun.

If you want to run 5.7" rods, use piston part number Keith Black KB147KTM, rings included, and Scat 5.7" rods, use rod part number 942-25700 available at Jegs.

If you want to run 6.0" rods, use piston part number Keith Black KB130KTD/KTM, rings included, and Scat 6.0" rods, use rod part number 942-26000 available at Jegs. Includes additional safety ring to prevent ends of oil rings from snagging in the wrist pin hole.

Gap top rings at 0.028". Gap 2nd rings at 0.020". Oil ring rails should be gapped ready to run.

Use Fel-Pro SFL1094 head gaskets. Clean block decks and heads completely and install gaskets dry.

New purchase intake manifold Edelbrock 7101 Performer or Weiand 8150 Speed Warrior. Used intake manifolds on craigslist, ebay or other used parts supplier 7101, 8150, Holley 300-36 Street Dominator or Weiand 8014 Stealth. All these manifolds will produce maximum torque and horsepower on a small block Chevy street motor.

AIR GAP INTAKE MANIFOLDS NOT RECOMMENDED FOR USE ON STREET MOTOR.

Static compression ratio will be 9.66:1 and squish/quench will be 0.035".

Use 1 5/8" or 1 3/4" long tube headers with 3/8" thickness flanges. Thinner flanges will warp up like potato chips from the heat of operation and spit out the gaskets. Install "H" pipe between the main pipes immediately after the collectors and use 2 1/2" tubing to the rear of the truck. Do not terminate the tubing under the truck or it will reverberate against the underbody sheet metal and sound like a mickey mouse exhaust system. Run the pipes to the rear of the truck, just past the bumper.

Motor will need 700 / 750 carburetor. Vacuum secondaries drive easier than double pumpers. Use a 14" x 4" air filter element so the motor can breathe.

Set initial spark timing at the crank at 12-16 degrees. Play with it and see what the motor likes. Reduce centrifugal timing so as not to exceed 34 degrees total, all in by 2800. Use manifold vacuum to run vacuum advance, NOT PORTED ADVANCE.

https://www.jegs.com/

.
12-22-2018 05:26 PM
Duker Digers The Block is like new inside, stock bore and not munch of a ring grove. The heads on the box they came in said 68 CC, guide plates, seals etc, and the heads are new and had a port job too. Ok, sounds like I use the 350 turbo trans, I will use the stock steel crank..and stock length rods . thanks for all your help.
Duker
12-22-2018 04:29 PM
techinspector1 OK, you have a 400 small block with stock bore, 4.125". Will you try to hone the cylinders for new rings or do you think the block will have to be cut 0.030" and then honed?

Have you measured the block deck height? Stock measurement is 9.025".

You're certain that the iron heads you have are 68 cc's? Will they be flat enough to run as is, or will they need a skim cut to flatten them out and make them compatible with a new steel shim head gasket?

What transmission will you run? An overdrive transmission WILL NOT work well with the 216 cam you have. You need an almost stock cam (max 206 intake @0.050") that begins making power down around 1000 to 1200 in order to be "up on the cam" (at 1700-2000) cruise rpm's with the overdrive transmission. It's not that the motor won't pull the truck using the 216 cam and an OD transmission, it will. It's just that the cam will not be in it's efficiency rpm's at road speed (1700-2000 rpm's) and will not make any appreciable fuel mileage. If you want to use a 3-speed transmission, the 216 cam (1800-5600 power range) will work and might make about the same mileage as the OD trans using the 216 cam.

Finding the proper piston will be the problem. You may have to pay the piper for forged pistons from SRP or other high-buck supplier and buy rods to make the combo work.

.
12-22-2018 03:26 PM
ericnova72 To use those Sportsman heads with their 64cc chamber on the 400, you need to find a piston with a 17 to 21cc dish volume to stay under 9.75:1 compression.

On the 327, a 5cc eyebrow flat top piston will get you right around 9.5:1 depending on head gasket thickness.

The 327 won't be any where near as much power or fun as the 400 IMO. Easily the 400 will make 100 more HP and torque, and be a lot more low rpm street friendly doing it.

When you look at pistons, watch out for reduced height "rebuilder" grade pistons, they will murder compression ratio and kill good quench characteristics at the same time, making the engine MORE octane sensitive even though they deliver a reduced compression ratio..
Stock 400 Compression Height is 1.560" with a 5.565" rod, if you use a 5.7" long common SBC rod from a 327 or 350, then the correct CH spec is 1.425".

Correct CH spec for the 327 is 1.675"
12-22-2018 01:00 PM
Duker Digers Yes Buzz, its a lighter truck, newer frame, so this chevy motor should do the job.
Duker
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