tweaking a 350-383

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
[B said:
liljack][/B]
Okay guys have a question before I spend the money on parts. I'm wanting to put a more peppy motor in my 1987 Chevy V10 swb. Right now it's got a 350 with mild cam aftermarket carb/intake combo is all. I'm wanting to build something that has some pep to it without busting something when I get on it. I have a 010 350 .40 over block, thinking of getting 1/4" (.250) domes, speedmaster (procomp) H beam 4340 rods, Sig Erson .444/.420 lift cam, double roller timing chain, 461 double hump heads that's been punched out to 2.08/1.96 valves, 1.5 ratio rockers, 750 edelbrock, accel distributor and super coil with 8.8mm wires. Okay on to my question will I have a clearance issue with the valves hitting pistons ? Will I need shorter push rods ? Thanks guys
rebuilt or new chevy 383 crank
http://www.superchevy.com/how-to/project-cars/sucp-0706-small-block-chevy-stroker-kit/
plastigty1.jpg

plastigty2.jpg

plastigty3.jpg

plastigty4.jpg

plastigty5.jpg

DEAL IN PROVEN FACTS NEVER GUESS , NEVER ASSUME
first step.

before you start panicking and potentially wasting money and time.
would be to assemble a single piston and rod assembly without rings,
but ideally with some old bearings on the crank and connecting rod and install the cam, in the block
( indexed with a simple,dot to dot timing on the timing gear sets should be ok at this point)
move that connecting rod and piston to all 8 locations and very carefully verify clearances (remember the rod clearance bevel faces the crank counter weight and the piston valve clearances face the outer block)through the full 720 degree rotational cycle, remember the cam spins at 1/2 the crank speed so the cam lobe comes close to the rod every other rotation,
and actually verify you DO, have or DON,T have a potential clearance problem
theres zero sense in runninbg around pulling your hair out and screaming until,
theres actually a PROVEN ISSUE too SOLVE (THERE MAY NOT BE!)
now if you find theres an issue to be solved you proceed using facts
and while your checking the cam lobe to connecting rod clearance check the connecting rod to block clearance ....yes the same minimum .060-.080 clearance is suggested
lobeclear.jpg

http://garage.grumpysperformance.co...earances-and-journal-surface.9955/#post-38385

rods that use bolts with nuts like pictured below will be weakened if excessively clearance ground
rod-grinding.jpe

stroker profile rods offer more clearance to cam lobes, and yes the stroker clearanced profile rods are available in both (h) and (I ) beam designs
scatrdx.jpg

hvsiclear1a.jpg


generally its a minor easily done clearance job
camlcc1.jpg

camlcc3.jpg

camlcc4.jpg

camlcc5.jpg

camlcc6.jpg

camlcc7.jpg

http://www.scatcrankshafts.com/index.htm
don,t forget to verify the cam to connecting rod clearances
a cams VALVE LIFT is determined by the DISTANCE the lifter moves as the cam rotates under the lifter base as it moves from the cam lobe base circle
(the closest the lifter comes to the cams center line)
up to the cam lobes ramp to the lobes peak,
(the furthest the lifter up off or from the cams center line)

don,t forget to carefully check the piston skirt to crank counter weight clearance, it should be a MINIMUM of .080 thousands

heres some pictures taken of an engine assembly that use a crank designed for a MINIMUM of a 6.25" connecting rod that was used with a 6.135" connecting rod

p140811.jpg

piston1.jpg

you can clearly see where the piston pin boss was being hit bye the counter weights, even though the builder checked one piston and found it had .025 clearance during assembly
pistontocrankclearance.jpg


the result was a trashed engine with lots of damage

piston2.jpg



http://www.chevrolet.com/performance/crate-engines.html

http://www.hotrod.com/articles/hrdp-0503-chevy-383-engine/

http://www.superchevy.com/how-to/en...-build-a-383-small-block-engine-sledgehammer/

http://www.superchevy.com/how-to/project-cars/sucp-0706-small-block-chevy-stroker-kit/

http://www.chevyhardcore.com/tech-stories/engine/building-the-little-383-small-block-that-could/

http://www.hotrod.com/articles/ccrp-0808-383-stroker-small-block-chevy/




ID suggest you select from heads from these sources

Jegs; 800/345-4545; Jegs.com

Summit Racing; 800/230-3030; SummitRacing.com

Scoggin-Dickey Parts Center; 800/456-0211; ScogginDickey.com


TRICKFLOW
http://www.trickflow.com/egnsearch.asp? ... 4294867081
http://www.trickflow.com/customerservice
1-330-630-1555 • 1-888-841-6556

BRODIX
http://www.brodix.com/heads/heads.html
479.394.1075

DART
http://www.dartheads.com/products/cylinder-heads
Dart Machinery; 248/362-1188; DartHeads.com


AIR FLOW RESEARCH
http://www.airflowresearch.com/
toll free: 877-892-8844
tel: 661-257-8124

Patriot Performance
Patriot Performance; 888/462-8276; Patriot-Performance.com


RHS
http://www.racingheadservice.com/rhs/cylinder-headshtml
Toll Free: 877-776-4323
Local: 901-259-1134

EDELBROCK
http://www.edelbrock.com/automotive_new ... main.shtml
Edelbrock; 310/781-2222; Edelbrock.com

BMP (world products)
http://www.theengineshop.com/products/cylinder-heads
Tel: 631-737-0372
Fax: 631-737-0467

BUTLER PERFORMANCE
http://www.butlerperformance.com/products/cylinder_heads/cylinder_head_labor.html
866-762-7527

BLUE PRINT ENGINES
http://www.blueprintengines.com/ind...sb-chevy-aluminum-cylinder-heads-cnc-machined
1800-483-4263

PRO-FILER
https://www.profilerperformance.com/
937‐846‐1333



“Quality means doing it right when no one is looking.”
Henry Ford

“Quality is like buying oats. If you want nice, clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse ... that comes a little cheaper.”

an hour to a week spent in careful research,
before you buy or install parts,
can save you months or frustration
and easily 300%-to 500% of the eventually,
cost incurred in buying cheaper parts,in this hobby!

it sounds like you've got a decent starting point that can be tweaked to provide more power but without knowing a few more facts, like what the trucks transmission is, your rear gear,ratio,and if you need to pass emission testing, your really working at a dis-advantage.
you need to actually MEASURE the valve train clearances, push rod length and piston to valve clearances so you can,t just guess!
Id strongly suggest that you step back and not get into a rush to throw a list of available parts together, and then try to deal with the potential problems that usually result.
the key to building any good performance engine correctly is to plan it out precisely,and do so with a KNOWLEDGE BASE , you get from reading up on what the more successful engine builders have previously accomplished,buying and reading a few books as a reference helps, and selecting components that match the intended rpm range and power band, will result in the best engine build for the cost outlay in most cases!
yeah! I'm well aware that 99% of the guys (including myself) learn the skills and develop insight in this hobby through trial & error, but thats both time consuming and totally unnecessary, and a waste of time and money!
having a mentor with decades of experience sure helps you avoid most problems, and asking detailed questions if far cheaper and faster than trying to figure out why some part broke or won,t fit correctly.
if you take the effort to CAREFULLY read the thread links below you'll find that a few well matched components can produce much better results than you might imagine, and certainly it increases the odds you'll have a far better finished project than randomly matched parts would have resulted in.
get out a legal pad, read the links carefully, list the questions your sure to have and lets discuss both what you have to work with in terms of tools, parts and of course finances that limit ALL of our projects!
if your like most guys you would love to go out and buy a long list of components or duplicate some engine build in a magazine article (where they fail to mention all the machine work costs and things they did to get the result without mentioning those parts of mods in the article)
but like most of us you don,t have a bottomless checking account balance or $200K in tools
what seems to be over-looked in many engine builds is simply the fact you'll almost always DEEPLY regret jumping into the engine build with both feet and waving your check book as you sink ever deeper into piles of parts receipts and machine shop bills, rather than stepping back with a legal pad, and a calculator and listing in minute detail exactly what you want to accomplish, and taking the time and effort too list and check out in detail what each machine shop procedure costs, why its required and how much each components costs, what your options are and how each component will add too or benefit the completed combo (or in some cases cause you time and grief)
stepping back and thinking things through in detail and listing the cost and potential problems and finding the solutions BEFORE you dive into the process may be a lot less fun, but in the long term its sure to cost less and result in a far better finished project!
yes you'll ALWAYS NEED to verify clearances carefully when assembling any engine and no, you can,t assume everything will fit just because its part of a component list thats suppose to fit correctly, simply because manufacturing is an imprecise process and mistake do get made occasionally!
if you build enough engines youll eventually see a strong relationship, between higher initial cost and that spending a bit more on heads and rotating assembly and valve train components tends to significantly reduce the problems and increase the engines long term durability.

Ive occasionally been asked what you can do too reduce the slack in the timing chain if your blocks been line honed,
to straiten the main bearings and that resulted in a slightly closer crank to cam center-line distance,
that results in a slightly increased slack in the stock timing chain sets.
a negligible amount of metal is generally removed from the main bearing saddles in the block, they usually try very hard to minimize that, metal removal so standard parts still fit,during a line hone , but they do sell slightly tighter timing chain sets to correct excess slack if that's required.
SBCprintCustom2.jpg



cloyesunder.jpg


https://www.summitracing.com/parts/clo-9-3100-5
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.005 in., Iron/Steel Sprockets, Chevy, Small Block, Set
for line honed blocks where the crank is .005 closer to the cam


https://www.summitracing.com/parts/clo-9-3100-10
for line honed blocks where the crank is .010 closer to the cam
Timing Chain and Gear Set, Original True Roller, Double Roller, -0.010 in., Iron/Steel Sprockets, Chevy, Small Block, Set
RELATED INFO

http://garage.grumpysperformance.com/index.php?threads/block-prep.125/

http://garage.grumpysperformance.co...k-after-a-cam-lobe-rod-or-bearings-fail.2919/

http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/tips-on-building-a-383-sbc-stroker.428/

http://garage.grumpysperformance.com/index.php?threads/stroker-tips-by-len-emanuelson.1249/

http://garage.grumpysperformance.com/index.php?threads/parts-prep-cleaning.6255/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-52466

http://garage.grumpysperformance.com/index.php?threads/what-con-rods-would-you-buy.942/

http://garage.grumpysperformance.co...ng-and-basic-piston-ring-info-youll-need.509/

http://garage.grumpysperformance.co...ting-started-in-the-car-hobby.339/#post-60187

http://garage.grumpysperformance.co...y-in-building-a-good-engine.11682/#post-54682

http://garage.grumpysperformance.com/index.php?threads/tbucket-engine-project-dart-shp.3814/

http://garage.grumpysperformance.com/index.php?threads/checking-piston-to-valve-clearances.399/

http://www.northernautoparts.com/part/ek-ek1097alb

http://garage.grumpysperformance.co...good-street-combo-your-after.5078/#post-14856

http://garage.grumpysperformance.com/index.php?threads/matching-parts-and-a-logical-plan.7722/

http://garage.grumpysperformance.com/index.php?threads/what-to-look-for-in-a-good-engine-combo.9930/

http://garage.grumpysperformance.com/index.php?threads/semi-fool-proof-cam-sellection.82/

http://garage.grumpysperformance.co...ing-a-383-sbc-combo-planing.12168/#post-58778

http://garage.grumpysperformance.co...gine-to-match-the-cam-specs.11764/#post-55571

http://garage.grumpysperformance.com/index.php?threads/383-information-overload.11137/

http://garage.grumpysperformance.co...e-springs-and-setting-up-the-valve-train.181/

http://www.wallaceracing.com/Calculators.htm
 
Last edited:
while these linked videos hardly begin to show all your options , on even a small segment of just the small block chevy engine theres several good tips and bits of info worth watching





 
The truck has a SM465 with 208 t-case, 3.42 rear gear 10 bolt GM at the moment but have a 12 bolt GM with 3.73 gears waiting to go in. The truck will be street only, occasionally redlight to redlight. Nothing major. I'm shooting for the lifted and loud scene with a squarebody truck.

the 12 bolt 3.73:1 rear differential would certainly enhance the trucks drive train strength and it won,t hurt in the cam selection either.
those trucks are fairly heavy and most guys I see building them swap to significantly larger tires.
the cam you listed is a bit on the smaller side,but it would help IF I knew the engines true compression ratio.
Id select a piston that matched that heads combustion
chamber size to get close to a 9.5:1 compression ratio,461 has a 64 CC chamber, with a .032 head gasket you need about a 16cc dish piston and
a cam similar to this, and
yes you'll ALWAYS NEED to verify clearances carefully when assembling any engine and no, you can,t assume everything will fit just because its part of a component list thats suppose to fit correctly, simply because manufacturing is an imprecise process and mistake do get made occasionally!
what seems to be over-looked in many engine builds is simply the fact you'll almost always DEEPLY regret jumping into the engine build with both feet and waving your check book as you sink ever deeper into piles of parts receipts and machine shop bills, rather than stepping back with a legal pad, and a calculator and listing in minute detail exactly what you want to accomplish, and taking the time and effort too list and check out in detail what each machine shop procedure costs, why its required and how much each components costs, what your options are and how each component will add too or benefit the completed combo (or in some cases cause you time and grief)
stepping back and thinking things through in detail and listing the cost and potential problems and finding the solutions BEFORE you dive into the process may be a lot less fun, but in the long term its sure to cost less and result in a far better finished project!

RELATED INFO
http://garage.grumpysperformance.com/index.php?threads/block-prep.125/

http://garage.grumpysperformance.co...k-after-a-cam-lobe-rod-or-bearings-fail.2919/

http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/

http://garage.grumpysperformance.co...tion-of-crank-durring-short-blk-assembly.852/

http://garage.grumpysperformance.com/index.php?threads/tips-on-building-a-383-sbc-stroker.428/

http://garage.grumpysperformance.com/index.php?threads/stroker-tips-by-len-emanuelson.1249/

http://garage.grumpysperformance.com/index.php?threads/parts-prep-cleaning.6255/

http://garage.grumpysperformance.com/index.php?threads/precision-measuring-tools.1390/#post-52466

http://garage.grumpysperformance.com/index.php?threads/what-con-rods-would-you-buy.942/

http://garage.grumpysperformance.co...ng-and-basic-piston-ring-info-youll-need.509/

IF your machine shop is pushing Eagle vs SCAT,they probably don,t have nearly the same % mark up, thats most likely WHY
I've used over a dozen SCAT forged rotating assemblies with complete satisfaction.
both SBC and BBC

http://www.scatcrankshafts.com/rotating-assembies/rotating-assembly-product-search/

http://garage.grumpysperformance.co...a-scat-rotating-assembly-be.11495/#post-52962

http://garage.grumpysperformance.co...-displacement-street-engine.10961/#post-48185

http://garage.grumpysperformance.co...re-you-getting-for-your-cash.9986/#post-46530

http://garage.grumpysperformance.com/index.php?threads/scat-vs-eagle.5877/#post-17912

http://garage.grumpysperformance.co...pes-of-crankshaft-steel.204/page-2#post-46231

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/#post-11766

http://garage.grumpysperformance.co...troker-tips-by-len-emanuelson.1249/#post-2674

http://garage.grumpysperformance.co...ing-rod-strength-h-vs-i-beam.1168/#post-41255

http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/#post-26199

http://garage.grumpysperformance.co...n-buying-used-engine-blocks.14305/#post-73107


IF your willing to read and learn , building a 450hp-550hp 383 SBC is not that difficult, but I can tell you from decades of building them, that most guys will find "DEALS" on mis-matched components too save a few bucks and skimp on quality components and precision machine work, and the result generally hurts both durability and performance a great deal as a result.
ID suggest you do detailed research, and a properly matched set of aftermarket aluminum heads that flow at least 250 cfm at .500 lift and a compression ratio near 9.5:1 for pump gas is a good starting point.
read the links and sub-links below carefully.
http://garage.grumpysperformance.com/index.php?threads/tbucket-engine-project-dart-shp.3814/
http://garage.grumpysperformance.co...383-build-that-is-now-going-to-be-a-400.7804/
http://garage.grumpysperformance.com/index.php?threads/cam-help-for-new-383-build.13099/
http://garage.grumpysperformance.co...-selecting-budget-383-heads.14620/#post-78229
http://garage.grumpysperformance.co...ing-a-383-sbc-combo-planing.12168/#post-71932
http://garage.grumpysperformance.com/index.php?threads/tweaking-a-350-383.13087/#post-68195


READ THESE THREAD's

and don,t skip the sub linked info
http://garage.grumpysperformance.com/index.php?threads/engine-balancing.3900/
http://garage.grumpysperformance.com/index.php?threads/engine-balancing.3900/#post-57940

https://www.crower.com/camshafts/chevy-262-400-hydraulic-cam-3893.html

http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/

http://garage.grumpysperformance.com/index.php?threads/dynamic-vs-static-compression.727/

http://garage.grumpysperformance.co...ber-volume-needs-clean-up-equalization.12474/

http://garage.grumpysperformance.com/index.php?threads/porting-can-help.462/page-3#post-59145

http://garage.grumpysperformance.co...in-height-compression-height.5064/#post-66240
 
Last edited:
Back
Top