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lumberjack_43 03-21-2014 04:51 PM

406 help
 
I picked up 406 short block has a new scat cast crank h6160p 4 vr pistons idealy I would like to hit 500+ foot pounds and not rev past 6000 rpm I'm very new at this so go easy on me my idea is this I mudbog and instead of holding 7500 rpm in a 350ci in first i would like to be able to shift into second and keep pulling (in my little brain this tells me i want torque) I know a set of afr 210 eliminators will get me there but id have to use my rent money for the next 2 months to purchase a set there is also no perfomance shops within 500+ miles of here i can pick up a bare set of motown 220cc, 64cc, 2.08" x 1.60" heads would these get me close? if not is there any other cheaper compitition for the afr 210? I would like to be around 500 hp am i in the range? or am i just blowing out my *** i also need cam help as i dont understand it all correctly yet.

ericnova72 03-21-2014 05:07 PM

As much as I love big HP 406 combinations, your use in a Mudbog truck means torque, not high horsepower. The AFR 210's are slightly too big, but you can get away with them if you are geared correctly. The Motown 220's are just too big....if your rpm drops a little too much the motor won't be able to recover the wheelspeed.

AFR 195's would be more apt in this situation. Or Dart Pro 1 195's, or Brodix 200's.

lumberjack_43 03-21-2014 05:24 PM

okay and 72 cc over 64 cc combustion chamber will be less compression right?

ericnova72 03-21-2014 06:13 PM

Quote:

Originally Posted by lumberjack_43 (Post 2210818)
okay and 72 cc over 64 cc combustion chamber will be less compression right?

That is true, but what actual compression ratio you have will depend on what piston - dish/flat/dome???

The more info you give us about EVERYTHING in the short block, trans, rear gear, tire diameter, torque converter stall, etc the better we can help you out.

You have given very little so far.

lumberjack_43 03-21-2014 07:15 PM

Okay they are h616p (flat top 6 cc relief ) pistons 5.7 rods as far as i know and the previous owner know theres no deck work scat cast internal balanced 400 crank will have a th400 manual hard hitting tranny 208 transfer case dana 60 front with 456 gears and dana 80 rear with 456 gears the tires get changed out from 35 inch tsl boggers to 40 inch monster mudders depending on the rules at the bog im. at anything else?

ericnova72 03-21-2014 07:45 PM

You'll want the 72 cc heads if this has to run on pump gas. Would be around 10.7-1 compression

What are your cam plans?? Intake and carb??

4.56 gear isn't much gear with those big 40" tires...or are you running in 4-low lock on the T-case??? If you are trying to do this in 4-High on the T-case you'll need something like 5.38 or more gear.

lumberjack_43 03-21-2014 07:58 PM

yes im aware of the gear selection with the 40s and i run it in the low side with them on. the 35s will be my tire of choice except for the bogs that let the 40s compete with 35s thats when i change to 40s. others have a limit in my class of 35s. I have no gas limitations so would the 64cc give me more power? and as for cams I have no idea where to even start help here would be GREATLY appreciated too. i also dont have a high stall torque yet either but plan to have one in the near future so we will build it for 3000 stall Would the holley truck avenger 770 cfm be enough for this build?

ericnova72 03-21-2014 08:09 PM

If you're willing to run racing gas, then the more compression the better, the 64cc heads will put you in the 11.3-1 range on compression ratio.

The 770 carb will work.

What type of cam do you want to use? Hydraulic flat tappet, solid lifter flat tappet, hydraulic roller, or solid roller??

lumberjack_43 03-21-2014 08:19 PM

Hydraulic flat tappet i also dont care about fuel mileage or vacuum *strictly using the truck for competition bogging* never driven on the road as it has 2 3/4 exhaust into 8 inch chrome kenworth stacks =]

bygddy 03-21-2014 08:34 PM

If its me, I would look at an even smaller head, the Dart SHP 180's
http://www.summitracing.com/int/part...make/chevrolet
Use a 0.025 HG
If you can swing a retrofit roller then I would look at this
http://www.summitracing.com/int/part...make/chevrolet
If not, then something around this
http://www.summitracing.com/int/part...make/chevrolet
Top with 1 5/8 longtubes
A regular performer intake with a 4 hole spacer.
I suspect something like this would make brutal low end.

lumberjack_43 03-21-2014 08:49 PM

Quote:

Originally Posted by bygddy (Post 2211258)
If its me, I would look at an even smaller head, the Dart SHP 180's
http://www.summitracing.com/int/part...make/chevrolet
Use a 0.025 HG
If you can swing a retrofit roller then I would look at this
http://www.summitracing.com/int/part...make/chevrolet
If not, then something around this
http://www.summitracing.com/int/part...make/chevrolet
Top with 1 5/8 longtubes
A regular performer intake with a 4 hole spacer.
I suspect something like this would make brutal low end.

so why the smaller cc? please correct me if im not right but this brings my peak torque down the rpm range? say with the 210 afrs my peak torque is at 5000 rpm with the 180s it brings my peak torque down to 4500 rpm just as example i pulled those numbers out of the air

bygddy 03-21-2014 09:12 PM

Small duration cam, small runner heads will absolutely bring your peak torque down, pulling a 6000# truck (I assume a full size 4x4?) With big heavy 35-40" tires. I would personally want as much down low as I could get
If budget was a big concern and fuel type wasn't i would honestly use a Vortec head on it.

TBARTA 03-21-2014 09:44 PM

195s, as ericnova72 said, are good for the 406 till about 6000 rpm range.The next part will depend on the octane youre running . For a 406 I would think a compression ratio of 9.5 ,( iron heads) 10 ( for aluminum) with at least 91 octane should work. 93 take that to 9.7 and 10.2, respectively. and so on. 9.5 on 91 with a 282 ish duration, at 4 degrees advanced , on a 106 lsa , 5/8 long tube headers , 2.5 inch collectors , about 30 inches long, ( scavenging and semi-supercharging, Should give you about 450 pounds of torque. 9.7 , 93 octane, 285ish duration ,again 4 degrees advanced,same lsa, 3/4 headers , 3 inch collectors , same length , about 470 pounds. After this we either port the heads or go 200 cc . ( probably better to port , depending on head choice) , then 10 to 1 , 95 octane , 290 ish cam ( all else the same including headers ),490 pounds or more. These specs are based on iron heads, good combustion chamber, quench ( biggy ), piston design, flat tappet and enough lift at the valve, ( .525- .575 ish ). I assume open collectors, single plane, spacer, 750-850 carb, (750 holley hp comes to mind). You need a good reworked HEI or aftermarket with a rev limiter minimum. Aluminum heads , .5 more compression. . For all this, 160-180 temps are mandatory. ( good rad, thermostat, cold air induction, etc) Btw, roller cam, everything changes, Slightly. I hope this helps.

lumberjack_43 03-21-2014 09:52 PM

http://www.hotrodders.com/gallery/sh...cf5203/cat/500

actually its a sunfire on top of a chevy frame

vinniekq2 03-21-2014 10:13 PM

mmember here has this 383,9.4:1 with AFR heads 210 cc
if this is too radical???


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