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Author Topic:   B-Mod, hp &torque
George Gilliland
Dirt Forum Racer

Total posts: 95
posted November 16, 2005 11:38 AM  
I run a 355 Chevy,9:1, with 441 heads (stock), stock cast iron intake with a Holley stock 500 two barrel and a #8 Midwest cam. I have never had one dynoed. What would you think would be the point of maximum torque and the point of maximum power?

Dirt Forum Racer

Total posts: 77
posted November 16, 2005 12:05 PM  
our big mod motors here in missouri are cranking out around 500horse and close to that in torque,but keep in mind these are 400 cube inch motors and bigger with aluminum intakes and big 2bbl carbs,we have one of the openes b-mod classes i have ever seen,they are more like a 2600lb pro mod.your motor is probably in the 400hp range and same in torque.hard to get power out of stk heads,intake,an stk 2bbl.hope this helps..

Dirt Forum Champ
Total posts: 1893
posted November 16, 2005 01:00 PM  
Dirttrackin94 alot of the motors in mo are in the 600-700 mark now. I know of one built in booneville that is claimed to be 716 on the dyno, average is like 625 for some of the higher priced motors. unless your talking about the b-mod, which about 500 sounds about right between large cubes and the small carbs. But the full open mods like at cms can be pushing over 700 sometimes. Of course some of them also have 12000-15000 price tags, or more.

George Gilliland
Dirt Forum Racer

Total posts: 95
posted November 16, 2005 01:40 PM  
I run a B-Mod and we are very limited in the engine department. Stock heads, intake, flat top pistons, 9:1 compression ratio and a stock Holley two barrel(500cfm). I have been told that the power on our engines ranges from 340 to 350 hp. What I am interested in is the Rpm at which the maximum torque and power is delivered. I am guessing the the torque is maxed at about 5500 rpm, and the horse power at about 6000 rpm. But these are purely guesses on my part. I would like to know if someone knows with more accuracy the Rpm for these points. By knowing these points I can make sure the gearing is correct. I greatly appreciate everyone's help! Thanks, George.

Dirt Full Roller

Total posts: 67
posted November 16, 2005 03:08 PM  
A lot of where your peak horsepower and torque are will depend on your camshaft and how it is degreed in. I run an IMCA mod with a 355. It has 461 heads and 13-1 comp. My peak HP is around 5500 and torque is at 4500. This is with a short duration cam (228 and 240 @ .050) with a 107 LCA. If you retard the cam 8 deg it bumps the peak to around 6000 and 5000. If you use a large duration cam you with 106 LCA you will see it go up to around 7000 peak hp and 5500 torque. With limited compression and heads you would be better off running short duration and wider LCA like a 112. This will give you the most from the low comp stock head set up. You will get better low rpm power and more torque. You have to utilize the static compression. By having a shorter valve overlap you hold the compression in longer which helps build more low end torque and HP.

Dirt Full Roller

Total posts: 37
posted November 16, 2005 04:06 PM  
Hey George is this a WISSOTA MW Mod? If so I will also be running one next year and I am having Homerun Engines in Alexandria, MN build my motor and it's a 350 bored 40 over so it comes out around a 355 and he said we can expect to see 385 hp and 385 torque on his dyno out of out motor combo. Hope this helps.


Dirt Forum Racer

Total posts: 77
posted November 16, 2005 04:45 PM  
zero im talking about B-mods,i know the pro mods are around 600-750 hp...the big b-mod motors here at fulton are pulling 500hp on 2bbl..our only rule is cast iron motors,billet 2bbls allowed and no roller cams...i run both pro and b-mods and my motor with a 2bbl is 500hp and with a 4bbl and timing change it will crank 630 easy..(414ci)....

george like i said before i bet your motor is around 400hp and close to that in torque,your engine is pretty limited per your rules...

Dirt Full Roller

Total posts: 51
posted November 16, 2005 04:49 PM  
Have you heard anything about whether montgomery and fulton have come together on rules for the B-mods

Dirt Forum Champ
Total posts: 5401
posted November 16, 2005 08:04 PM  
modfan i have been wondering if they have agreed on anything yet,i havent heard anything as of yet.

Dirt Full Roller

Total posts: 29
posted November 17, 2005 09:41 AM  
400 Is hard to acheive without a custom cut cam and a flowed carb.

George, I'd imagine you've got 330-350 HP to play with, no Idea on peak points though. You ran pretty well last year, and will miss racing you weekly (Racing in town, and Independence next year).
Might call PTM and talk to Doug and see what he says about peaks, he's got an idea.

Brett Ladehoff
#12 360 Mod (X) also

George Gilliland
Dirt Forum Racer

Total posts: 95
posted November 17, 2005 06:53 PM  
At Webster City we run a 5.43 and turn 6900. This year I ran Webster City and Britt. Next year I plan to run Webster City and Fort Dodge. I ran a 5.29 once this year and it did not work great when it was tacky during the heat, but was pretty good on the dry slick. Thanks for the replies. George.

Dirt Maniac

Total posts: 166
posted November 18, 2005 05:04 PM  
hey george the #8 with our motors makes peak power around 6500 so you will want to turn 6800-7000 RPM's, and as for dyno #'s they dont mean ****!, on JR's dyno in ankeny it would say u have about 330HP if you take it to PTM and dyno it they would say you have 400 because they change the correction #'s so everyone actally thinks they build good motors, i will give u a example, one JR 650HP 393 on gas on a restart blew blows away a 740 HP PTM 420 everytime they drag race so in conclusion dyno #'s dont mean ****, and if you want to pick some easy power up get a baker or dorton carb that will pick it up quite a bit

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