406 SBC Build

L

Lmus10

Member
Just joined the site. Have read all of the 406 combos I could find. Would like for your opinions, thoughts, recomendations on a camsahft for this build.
Stock 400 block bored 0.030". Scat cast steel crank, 6" forged rods, forged flat top pistons. Block decked to 9.000". Using an older set of Dart Iron Eagle heads 200cc runners with 64cc cambers. Some mild port work has been done and 2.05" intake valves have been installed. Due to money constrants would like to stay with a mechanical flat tappet cam. Also keep the RPM's below 6500. Intake manifold choice is open. I do have Holley single plane intake but I'm thinking an RPM Air Gap may be a better choice.
This is going in a 1991 S-10. 350 turbo 3500 stall converter with a Ford 8.8 rear and a 4:10 gear.
Would also be interested in what you think this combo will make in HP & Torque. Or is it a pig?
Open to all suggestions.
Thank You for your time.
 
that combo as listed , (with rpm air gap) and decent long tube headers,
with a low restriction exhaust and a 750 holley,
sounds like it has potential, its basically a commonly used old school combo thats been used for decades.
personally Id be looking into a crane 110921 flat tappet solid lifter
kit with matched lifters, if I was not going with a roller cam.
keep in mind that youll benefit from a STATIC compression ratio above 10.5:1 but over 11.2:1 the octane fuel required gets noticeably more difficult to locate.
for street use steel heads should have about a 8:1 dynamic compression ratio, with aluminum heads you can generally get by with up to about 8.4:1 dynamic compression ratio.
and a quench distance in the .040-.042 range.
keep in mind a single plane intake and a manual transmission ,fairly heavy flywheel, and a differential with the correct rear gear flywheel weight and slicks will allow the engine to launch and rpm quicker, but your current combo should still produce impressive E.T and horse power if its correctly assembled, and tuned


if your assembling any engine,
ideally you and your friends should have and hopefully read and did read carefully the linked info.
http://garage.grumpysperformance.com/index.php?threads/bearing-clearances.2726/

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

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

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

http://garage.grumpysperformance.co...piston-to-bore-clearance-on-your-block.14251/

http://garage.grumpysperformance.com/index.php?threads/maximizing-piston-to-bore-ring-seal.3897/

http://garage.grumpysperformance.com/index.php?threads/piston-to-bore-clearance.4630/

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

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

http://garage.grumpysperformance.co...ectly-and-get-it-to-last-cam-install-info.90/

http://garage.grumpysperformance.com/index.php?threads/valve-train-clearances-and-problems.528/

http://garage.grumpysperformance.com/index.php?threads/correctly-adjusting-valves.196/

why not call the tech guys at crane and talk to them?
crane (386)310-4875
https://www.summitracing.com/parts/crn-110921

http://www.superchevy.com/how-to/148-0306-chevrolet-406-big-block-torque/

crane110921.jpg


you may find this video interesting

if you were going to go roller cam
crane119651.jpg


https://www.summitracing.com/parts/crn-119651
 
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What is the hp/torque potential with this cam?
Forgot to mention that this is a going to Drag Race only truck.
 
depending on tune Id be looking for close to or slightly over 500 flywheel hp N/A
on similar low budget builds, have been common.
get the trucks weight down as far under 3000lb as you can,
and suspension and tires set up,
and low 11-high 10 second 1/4 mile runs at just over 120-125 mph have been done quite commonly with similar builds
what youve isted is a very common list of old school components
Swap to that single plane holley intake,
stick a 150 hp wet nitrous plate on the engine,
use 105 octane fuel, and you could be even faster
a good deal depends on the care taken in engine assembly,
reducing car weight and selecting tires and proper geometry used with suspension components
http://www.wallaceracing.com/et-hp-mph.php
https://robrobinette.com/et.htm

 
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The ET/MPH posted, is that with the Air Gap Intake? and what would the octane requirement be?
Also would there be any benefit to a 1.6 ratio rocker on the intake side.
This is good info. Thanks
 
yes RPM intake,(maybe a 2" open spacer, you'll need to test)
1.6 ratio FULL ROLLER rockers won,t hurt, and may help,
certainly port matching,
chamber polish,
multi angle valve job
and un-shrouding the combustion chamber, WILL HELP
you'll more than likely need the high octane race gas,
even without any changes like nitrous!
keep in mind its both the component parts and the care taken,
in fitting and modifying and getting the proper clearances ETC.
during the assembly process that adds up
Id also use 1.6:1 roller rockers on a mild 383 SBC build in most cases
http://www.pbm-erson.com/Catalog/Erson/Camshafts/Retro_Fit Hydraulic Roller_E/ERSE119815
ersonr4.jpg

ersonr3.jpg

ersonr2.jpg

ersonr1.jpg

https://www.ebay.com/itm/Erson-Cams-803-16-SB-Chevy-Extreme-Duty-1-6-Aluminum-Roller-Rockers-7-16-Stud/173036288915?_trkparms=aid=222007&algo=SIM.MBE&ao=1&asc=20160908110712&meid=dd2ef46908f84d1994db01594e3da770&pid=100677&rk=4&rkt=8&sd=173036285468&_trksid=p2385738.c100677.m4598
http://garage.grumpysperformance.com/index.php?threads/porting-can-help.462/page-3#post-59145

http://garage.grumpysperformance.co...needs-clean-up-equalization.12474/#post-62647

http://garage.grumpysperformance.co...olishing-combustion-chambers.2630/#post-48319

http://garage.grumpysperformance.co...ing-parts-and-a-logical-plan.7722/#post-57946

http://garage.grumpysperformance.co...at-angles-and-air-flow.8460/page-2#post-32923
 
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Friend (?) just gave me set of forged pistons (TRW) with connecting rods attached.
All I can find on the rods are the letters 'GMD'. Who manufactured these? Any good?
They are pressed in. The beam has been polished and 3/8" ARP bolts have been installed.
Will they be ok for the above set-up? If not, how hard is it to press the pins out?
 
We need pictures.
Without being able to see the rods, let me say this first:
Good rods are incredibly cheap these days. You don't know any of the history of these rods, and you want
to build a 500 HP engine. Buy new rods. Besides, they can't be checked until they are separated from the pistons.
Plus they need to be the correct length for your planned build. If the pistons are correct for your application, then
concentrate on re-using those.
If you have a press and the proper driving tools, you can press the pins out yourself. You cannot re-assemble them
yourself.
From your first post, it sounded like you already had a forged, balanced rotating assembly.
At least that is the impression I got.
 
'GMD' Ive seen stamped on big block chevy marine engine rods

General Motors Division
 
Sorry, I can see where it is misleading. In my mind I was just stating the list of parts I was considering.
Like with most people this is a budget build. I don't mind replacing the rods, just wasn't sure about removing the
wrist pins without damaging the pistons. Keeping the pistons would help with budget.
 
you can,t just swap in a different set of pistons or connecting rods,
the pistons must be the correct bore size and the rods and pistons must be balanced to the crank counter weights,
connecting rods can be converted to full float pin design but the cost is usually not worth it,
as better & strong rods can be had at a reasonable price.. and most pistons designed for pressed in pins are rarely top quality and most are not forged,
or the correct weight to balance the rotating assembly , plus theres side clearance , bearing size, quench distance and a dozen other potential issues

common sbc pin height info
Specs
  • Comp Height 5.565" Rod - 1.561
  • Comp Height 5.7" Rod - 1.433
  • Comp Height 6.0" Rod - 1.13
  • Pin Diameter - 0.9272
READ THESE THREAD's
http://garage.grumpysperformance.co...-the-rabbit-hole-with-alice.10933/#post-66925

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

http://garage.grumpysperformance.co...t-don-t-destroy-your-budget.10958/#post-48174

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

http://garage.grumpysperformance.co...ng-rods-from-pressed-to-full-float-pins.6909/

http://garage.grumpysperformance.co...ng-piston-pin-height-compression-height.5064/

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

http://garage.grumpysperformance.com/index.php?threads/balance-damper-question.10462/

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

http://garage.grumpysperformance.com/index.php?threads/piston-to-bore-clearance.4630/

http://garage.grumpysperformance.co...guess-on-clearances-and-journal-surface.9955/

http://garage.grumpysperformance.com/index.php?threads/obtaining-desired-clearances.4324/

http://garage.grumpysperformance.com/index.php?threads/engine-block-cylinder-wall-thickness.976/
 
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