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Author Topic:   350 power combo (tired of being beat)
mlpowley
Dirt Full Roller

Total posts: 26
posted September 04, 2005 04:34 PM  
i run a stock class with a legal motor im tired of being beaten. we run a 350 with flat tops deck height is 10 thousand and a 650 holley with a 72cc head... help i cant run with there horsepower

goinrcn44h
Dirt Freak

Total posts: 205
posted September 04, 2005 04:47 PM  
are you sure its their horsepower thats beating you..? To win its usually not the best engine. that never hurt things but it wont take a mid packer and turn them into the big-richard of the area.
44H

Alltel
Dirt Maniac

Total posts: 180
posted September 05, 2005 09:49 AM  
I used to run a now defunct class that had a 360 cubic inch rule and got lapped every race. Years after the class folded, I talked to the guys I used to race against and I was the only one running under the 360 limit. The majority were running a 406. When the class folded, most of us went to IMCA modifieds. With the same motor, I won rookie of the year over all the guys that used to lap me every week because the little tires didn't allow the HP to stick to the ground. Motor caused me to go from running dead last in a field of 17 to running at the front of a field of 30.

The whole time I was running the other class, I was constantly getting told that it was me or my setup abilities that were getting beat and not the motor. BS. The same guys now come to me to set their cars up.

From what I've seen, if your going to run in a class that has motor limitations, the only way to win is to CHEAT, CHEAT, and CHEAT again. That is why I will never go back to racing anything but modifieds because there are no motor rules. If I get out horse powered, so be it. At least it was legal.

In other places it may be different, but around here, teching consists of weighing the cars when the scales work and thats it. You won't find a legal car even close to the top 5.

I've heard all my life that big motors don't make you fast, but none of the guys that said that were willing to trade. Now, if you can't drive, a big motor won't make you win, but if you can drive, a little motor will make you lose.

Raz_900
Dirt Forum Champ
Total posts: 635
posted September 05, 2005 06:17 PM  
quote:
Originally posted by mlpowley:
i run a stock class with a legal motor im tired of being beaten. we run a 350 with flat tops deck height is 10 thousand and a 650 holley with a 72cc head... help i cant run with there horsepower

What are the rules? Just in case you care to stay within them.

There's probably about 25 things you're currently not doing that are 100% legal. Each one might only be worth 1, 2 or maybe 5 HP, but combine them all and you have 50HP more than you started with.

I've run against quite a few 377, 383 and 406s with my 355s and at least held my own. I had to have the most out of the tires and chassis where they just had to be in the ballpark. The wider the tires, the worse off a smaller motor is. With a 12"-14" wide contact patch you can be pretty far off chassis wise and drive like a moron and still finish in the top 5 if you have a 410 hammer under the hood. Try that on 8"-9" wide tires and you'll be lucky to find the top 10 on at all.

For starters, mill the block for zero deck height and get the chamber size down on the heads. 72ccs with flat tops and 10 in the hole makes for lame compression. Cut the block that 10 and the heads 20 and you'll raise compresion a half point or more. That right there will add 2%-3% power across the board, say from 350 HP to 357-360 HP. Doesn't sound like alot, but that's just the beginning.

[This message has been edited by Raz_900 (edited September 05, 2005).]

mlpowley
Dirt Full Roller

Total posts: 26
posted September 05, 2005 06:50 PM  
our rules state that we have to have flat tops and 10 in the hole and that we must run 72cc heads. 8" hoosier emod 500 tires i have the only metric at the track.

dirt_mopar99
Dirt Forum Racer

Total posts: 94
posted September 05, 2005 08:03 PM  
I am not an engine builder nor do I know much about GM motors, but I was wondering what cam lift do you have to run? What are the porting rules? Even with no legal porting in a rule book it usually says very little about how your valve job. Good engine builders seem to have a way of back cutting the seats to give you a little more flow. If you have a spec. cam lift does it say anything about rocker ratio? How when they tech do they check lift? at the valve or pushrod? Do you have any advance in your cam?

mlpowley
Dirt Full Roller

Total posts: 26
posted September 06, 2005 05:02 PM  
425 lift any duration. 3angle valve jobs ok. no porting of head

dirt_mopar99
Dirt Forum Racer

Total posts: 94
posted September 06, 2005 05:36 PM  
We have a 450 lift rule. We look for cams that come up very quickly on max lift and that keep the valves closed longer on the comp stroke. Crower I know makes Chevy cams like this. In my Mopar we run an Isky. My engine builder says cylinder pressure is the key. The Chev guys also run a "launcher" cam that comes up on lift very quickly as to possibly open the valve more than advertised. I have seen engines out of old pickups with this cam setup be very quick. Crower or Isky should be able to help!

------------------
Speed Kills, Drive a Chevy and live forever!

maximus
Dirt Roller

Total posts: 21
posted September 06, 2005 06:27 PM  
something else you need to do is get atlest a 6 inch rod in it. I run in the cruiser class and there are 5 guys in my class that are running 383 strokers (cheaters) and my 355 runs .49 seconds faster lap times than them. my cam is also designed to pull the 18lbs of vacum which there are a few more guys that have vacum pumps mounted under the seat tied into the trans vacum line so they can run bigger cams and they still can't hang with me. remeber that everthing in the engine has to work together so don't get to big of a cam or to much carberation.The most inportant thing is take the car to a professional and have it setup.

dirt_mopar99
Dirt Forum Racer

Total posts: 94
posted September 06, 2005 09:39 PM  
Very true Max, A good scale job will work wonders!

racer17j
Dirt Forum Champ
Total posts: 5390
posted September 07, 2005 07:04 PM  
quote:
Originally posted by racer17j:
just depends on how much you want to spend


Thats the key right there, if you have the money you can be fast and technically legal. In most cases it takes alot more $$$$$$ to make legal parts fast than it does to go out and buy a full blown racing part, but there are guys out there on the track who are putting the money into stock appearing parts all day long...

nine finger
Dirt Forum Racer

Total posts: 76
posted September 09, 2005 08:05 AM  
do they ever tear motors apart to check. if they dont whats the problem.

chickenlittle
Dirt Full Roller

Total posts: 64
posted September 11, 2005 09:20 AM  
You need a good cam to make low end torque. You need to run a wide lobe centerline angle. Probably in the range of 108-114. I would also use a short duration on the intake (220-230 @ .050) and a longer one on the exh (230-240 @ .050). You basically want a short valve overlap period to utilize the static compression. It holds more pressure in at low rpms and gives you a ton of response of throttle. You will sacrifice some top end power, but it may not hurt you on a short track with tight corners. You can also use high ratio rocker arms like 1.6 or 1.7 to open up the valves more. This would help your top end power. Hope this helps.

[This message has been edited by chickenlittle (edited September 11, 2005).]

[This message has been edited by chickenlittle (edited September 11, 2005).]

dirt_mopar99
Dirt Forum Racer

Total posts: 94
posted September 11, 2005 08:07 PM  
Chickenlittle is talking about the type of cam I am running and has said basicly what my engin builder is doing for the fast chevs.

johder
Dirt Forum Racer

Total posts: 100
posted September 17, 2005 01:40 PM  
get a 400 block...looks identical to a 350...throw a 350 crank in it to get a 372...bore it 30 over and make a 377....or you can but an old 327 crank in it and if you have your limits..our track is 355 max...so destroke it with the 327 crank...i believe it should put you around 352-353 cubes if i am not mistaken....it will twist to 7800 pull the whole way to 7800...youll come out of the turn 6500-6800 and youll be right back in the power range to start pulling again.....make sure like all above said...you have a matched cam for this rpm range.....and that is how you make a small cube motor "FAST", when you pass them down the straight....they will be asking "man did i put my ear plugs in". cuz it will sound like your turnin 10grand fromt he stands....its awesome

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