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Author Topic:   355 combo and HP level
Burque
Dirt Forum Racer

Total posts: 98
posted February 17, 2005 11:52 AM  
Ok guys I have a 355 4 bolt stock bottom end with this in it.

Flat tops
441 heads milled 10 thousands
.600 springs
1.6 Roller Rockers
Midwest #8 Cam
Double roller timing chain
Original Toker aluminum intake
750 Holley DP
Headers with crossover pipe
HEI with MSD mod and coil

Does anyone know what type of horsepower this combo makes? I had decent power last season but was under geared. I will run about 6500 on 12í Hoosier 86 roll out. Last year only turned 6000 with 10í street tires; will this be a noticeable difference with better tires and a better gear? If not would be adding on my double hump heads make it any better?

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted February 17, 2005 12:11 PM  
425 maybe 435

RangeRover
Dirt Freak

Total posts: 279
posted February 17, 2005 02:15 PM  
389.7

nailngoracing
Dirt Maniac

Total posts: 170
posted February 17, 2005 02:56 PM  
maybe 375...on the high side

racin78p
Dirt Freak

Total posts: 333
posted February 24, 2005 02:09 AM  
Better tires can get you around the track faster. More gear can get you out of the corners faster and keep the power on down the straights (if your engine can breath to that rpm). Both of these can drop your lap times. Switching intakes and a smaller carb (750 is kind of big for a 355), say a 650 cfm can increase power quite a bit. Select carefully, do alot of research before buying anything. The camels might be better. Can you do any porting?

Looking at what you have right now in the motor, I'd say it has 350 to 375 max hp. More near the 350 range.

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racin78p
if it ain't fun, then don't run

Burque
Dirt Forum Racer

Total posts: 98
posted February 24, 2005 12:21 PM  
We cannot port or polish, just bigger valves and milling. My humps got the stock valves in them now. I had the humps in last season but stripped a rocker bolt. When a put on my 441 it seemed like I had quicker acceleration, but also changed from my Torker 2 to an original Torker. So I really donít know if it was my intake or heads.

I had planned on my 406 this year but decide on new tires, carb, and a better setup. So the 355 will have do for now. I will think about a new intake if I can get my money square.

Istock66
unregistered Total posts: 98
posted February 24, 2005 06:39 PM           send a private message to Burque   Edit/Delete Message   Reply w/QuoteBBBBBB
depending which stock pistons your running you could be as low as 8.5 to 1.

325 horse would be pushing it.

your cam is too big and so is your carb

that cam works ok in my 406 motors, but not as well in my 383s all are 13-1 at least.


stockcar5
Dirt Forum Champ
Total posts: 578
posted February 24, 2005 08:03 PM  
i agree that the 4bbl is helping alot. now if that was a 350 2bbl then i'd say 325 is right on. i'd guess around 400.

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www.geocities.com/dirtstockcar5

racin78p
Dirt Freak

Total posts: 333
posted February 25, 2005 06:33 AM  

To Burque; If it where my set up, I'd get a more up-to-date intake, drop to a 650 cfm carb, and look into getting the "hump" head fixed. I can't remember which of the two flows better, but I believe the camels do. Do they have the 2.02 or 1.94 intakes? Either way, this is just my thoughts. If the car was quicker with the changes you made, and with the new tires ect., maybe just run the urine out of it and have yourself a blast! That's what it is all about anyway, right? Race on.

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racin78p
if it ain't fun, then don't run

[This message has been edited by True Blue (edited March 02, 2005).]

Burque
Dirt Forum Racer

Total posts: 98
posted February 25, 2005 06:16 PM  
Well guy's didn't want to ruffle any feathers hear. I think I was close to 9 to 1 with my pistons, but could be wrong. I plan on switching to humps, and got my eye on a 4777 holly right now. As to horsepower I just wanted to see where I stand compared to the guys I race against. And if I am only at about 325 then I must be lower then some stock 350 with hydraulic cams.

Does this cam seem too large for my setup and if any one could enlighten me on a good one from Midwest, please do so.

ryan
Dirt Forum Champ
Total posts: 776
posted February 26, 2005 12:06 AM  
Get scruu in studs and mill your double humps. I think the flow between the two heads maybe similar but you are gonna gain compression with the humps. The popular cam around here is the #1 cam (.504)with or without 1.6 rockers. I don't personally care for it I also ran the #8 and wasn't to impressed either. With that cam and rockers you are running .565/578 lift. I have a 11 to 1 355 w/bowtie heads and I don't go that big. The cams I buy now cost more but they work better(for me anyways)

[This message has been edited by ryan (edited February 26, 2005).]

locorace27
Dirt Roller

Total posts: 14
posted February 26, 2005 04:50 AM  
Burque, your description of your motor is far to vague for anyone to estimate the HP. accuratley.
However, the fact that you asked such a vague question leads me to believe there is nothing else there. In which case it would likely be in the low 300 range, as many have already said.
The trap that many new racers and engine builders fall into is carbing and/or caming their engines out of contention.
It takes a lot of other developments before a SBC begins to be starved for fuel.


gould
Dirt Forum Champ
Total posts: 730
posted February 26, 2005 05:59 AM  
on my desktop dyno this is what i got

409hp @ 6000
410tq @ 4500

i tried some different cams, they all are around the same numbers

Alltel
Dirt Maniac

Total posts: 180
posted February 26, 2005 07:30 AM  
I've ran basically the same engine from the specs you've given. On the chassis dyno it made 340 horses. Only difference was I had a MidWest #2 cam.

Burque
Dirt Forum Racer

Total posts: 98
posted February 27, 2005 06:05 PM  
Well thanks guys I thought that the #8 cam might be too much with my 1.6 rockers. I figured it would be great for the 1.5 but pushing it with what I have now. Well I think either way I look at it; I will probably be out powered. I will work with my setup to gain more experience before building a powerhouse. Thanks Guys!!!

eenfield
Dirt Maniac

Total posts: 116
posted February 27, 2005 06:06 PM  
The difference between the 441's and the double humps is not drastic flow wise... The humps will raise your compression a point or so. In your situation I think you could use more.

Concerning the carb, I honestly dont think its hurting you at all. When doing the math trying to figure out how big of a carb to go with, inevitably you come up with 600-650cfm on a 350inch engine. However, in the real world the 750 almost always comes out on top. Stay with a 4150 style Holley (You did mean HP, and not DP right??) and away from the 4776/77's.

Just must my two cents worth.

Istock66
unregistered Total posts: 116
posted February 28, 2005 05:19 PM           send a private message to eenfield   Edit/Delete Message   Reply w/QuoteBBBBBB
heres why I said 325 hp maybe!


out of my chiltons all 350 options listed.

1969-70 255 or 300hp
1971 245 or 270hp
1972 165 or 200hp
1973 145 or 175hp1974 145 or 160 or 185 hp
1975 145 or 155hp

so you may have started quite simply with a very low hp 350 to begin with.

putting that cam in a 8.5 to one motor isnt going to add 125 hp.

badnail
Dirt Newbie

Total posts: 4
posted March 01, 2005 07:02 PM  
I agree with Istock66 and Alltel that motor would be lucky to get 325hp. I had a bit better motor than that and only had 350hp.

racin78p
Dirt Freak

Total posts: 333
posted March 01, 2005 07:22 PM  

Hey gould: 409 and 410? I don't think so. I do not want to ruffle the feathers here, but having done the "DYNO" thing as it is called, and with stuff that Burque has in his engine, I can't in a good couple of years see how his combo is anywhere near 400. No, I've been around too long for that jibe. Ain't happening.

To make 350 horses is not a hard or costly feat. To get over that and the money starts to roll.

RACE ON.

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racin78p
if it ain't fun, then don't run

[This message has been edited by True Blue (edited March 02, 2005).]

nailngoracing
Dirt Maniac

Total posts: 170
posted March 01, 2005 08:10 PM  
spend the money and have it dyno'd!

I put my money on 355 hp give'in 20 more or take'in 55 less.

300-375...most likely 355 or less!

racin78p
Dirt Freak

Total posts: 333
posted March 01, 2005 08:42 PM  
Dear Heaven above, there is another sane individual as such as I,...

I concure, nail, I concure.

Please Race On.

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racin78p
if it ain't fun, then don't run

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 01, 2005 09:01 PM  
You must not realize that carburetor helps. The desktop dyno is close. I'd say anywhere from 375-425. We had a motor similar, with a stock 2bbl intake, same cam, same pistons, same heads, same crank put out around 390 on the dyno.

waltonjr1
Dirt Forum Champ
Total posts: 516
posted March 02, 2005 05:22 AM  
It does no good to run that big of a cam and carb with those heads. The max cfm carb I would put on that engine is 500. Xtreme, the bigger the carb is NOT the better on any engine combo. You can only force so much fuel and air down those little intake runners, with the correct size carb you will have more velocity and a better air/fuel ratio.


Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 02, 2005 08:52 AM  
We run the same combo, and when we feel like making some real power we bolt on a 4 bbl 750 and it goes twice as good. Yes you can get too big of a carb, but in this case 750 isn't big at all. This is a common claim motor for IMCA Mods. one thing he didn't mention is what type of fuel he runs, alky will add about 25 HP

19J
Dirt Freak

Total posts: 370
posted March 02, 2005 09:45 AM  
I run close to a 500 on my 4 cylinder. Why would a 750 be too big if he is turning more rpms than i do and he has twice as many cylinders. Im supposed to turn it up around 6 but still working on that. It will provide plenty of power.

Burque
Dirt Forum Racer

Total posts: 98
posted March 02, 2005 10:40 AM  
Well I am just using racing fuel were not allowed to run anything higher in the Street Stock. I am changing my cam to Midwest number 5 I believe. It comes in about .504 lift and a littler under .550 lift with my 1.6 rockers.

I guess asking about HP levels was just asking for it!! When I got my motor it was suppose to be about 300 horses stock. I was just tiring to see what my cam, roller rocker, and carb did for it. I guess about 25 50 horses. I guess itís not to bad, but man HP cost some serious money!!!!

I think with the tires and setup I got this year I will do a lot better. Now the big dogs will out horse me. But I believe I will still be competitive with most the drivers out there.

racin78p
Dirt Freak

Total posts: 333
posted March 02, 2005 08:12 PM  
Drive the car Burque. Kick their buttocks, with maybe less hp. So what. Drive the car and be FAST! HAVE FUN. RACE ON.

To those of you who believe that a BIG HUGH CARB AND CAM is equal to HUGH BIG HORSEPOWER NUMBERS,... call any cam manufactor, or head manufactor, and ESPECIALLY ANY CARB manufactor. Listen to what they have to say. 750 cfm on anything smaller than a 383/400 better have some serious goodies to be able to max what that carb is SUPPOSSED to do for the engine it is on.

Make some calls all you non-believers.

Race on.

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racin78p
if it ain't fun, then don't run

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 03, 2005 12:07 AM  
I've made the calls and know what I am talking about in this situation. You can over carb, but in this case it is not overcarbed. More carb the better in this case. Parts don't make horsepower, the right cam, right carb and right exhaust will make just as much power with hyperutectic pistons and stock rods as pro tru's with h beam rods, just one lasts longer then the other.

stockcar5
Dirt Forum Champ
Total posts: 578
posted March 03, 2005 10:55 AM  
who said a HUGE carb and HUGE cam make HUGE power on this post? and why do some people think a 750dp carb is huge?? and since when was a 248/251 @.050 cam huge??? thats the only midwest cam that has a duration less than 250. i'd hate to see what a "small" cam is!!

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www.geocities.com/dirtstockcar5

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 03, 2005 11:32 AM  
If you stuck some big hog carb and put some big huge cam in that motor then you wouldn't see the power that you would if you had the right cam and carb. Those heads and intake can o nly take so much, yes, but they can still make power above 400 HP like they are built right now. Now if he had lets say stock heads on there with no work done to them and a smaller cam like a .500 lift cam, he might be in the 350 range.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 03, 2005 11:35 AM  
Also what size valves are in the motor and what kind of port work if any has been done?

That 5.7 Rod gives you a lot of torque, now if you have a 2.02 Intake you'll make HP.

Burque
Dirt Forum Racer

Total posts: 98
posted March 03, 2005 11:43 AM  
Well my humps are 2.02 I think by changing them I lost some good horse power. I will be sending them in to the shop for some fixingnext week . We cannot port or polish just mill screw in rocker valve job, just the basic.

Like I said this year I will run it hard as I can and get my setup good. Good luck to all guys out there this year!!!

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 03, 2005 01:59 PM  
they are 2.02 and you think you lost power???? or that you changed from the humps and think you lost power??? Either way that motor should run pretty stout for what is in it. It sounds like your running about the same thing we do with just a bigger carb.

Burque
Dirt Forum Racer

Total posts: 98
posted March 03, 2005 02:08 PM  
What I mean is by changing from the humps to the 441's I lost power. I have decent engine and can compete with it fine. I might keep all year if I can hook it up good all year.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted March 03, 2005 02:15 PM  
Yeah the humps are definately going to help produce HP. With Humps on there and big vales your looking definately at the 450 HP range. The IMCA Mod Claim motors that we build produce around 500 on alky with about the same parts and minimal port work. Anything beyond 500 HP is hard to acheive with Hump heads and the cam you've got in there. You might consider a custom cam also. They are well worth the money.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted March 03, 2005 02:27 PM  
My guess is you are around 375-400. Other than the headers and cam you arent really that much more than stock. With flattop pistons you prob have around 9-9.5:1 compression depednign on piston, gasket etc.

I would put the hump heads back on.

You are on the right track with the 1.6 rockers except I wouldnt do it for extra lift. I'd do it to get the valve open sooner. Id look for a cam that had more agressive ramps that would get the valves open as fast as you can without tearing stuff up. The stock heads prob dont flow that well over maybe .525 lift anyway, its more important to get the valve open sooner than open farther. Comp Cams Xtreme series comes to mind but I'm sure there are others out there too. Also if you are only turning 6500 I'd look for something a little smaller especially with a single plane intake, maybe more like low to mid 240's at .050.

750 might not be too big for a carb depending on what you are doing. But keep in mind a smaller carb will help pull out of the corner but go too small and you'll choke off the top end. A 650 would be more than enough to supply that motor even turning 7000rpm. A vacuum secondary carb might even help as it would only use what the motor needed.

[This message has been edited by dirtbuster (edited March 03, 2005).]

racin78p
Dirt Freak

Total posts: 333
posted March 03, 2005 07:27 PM  
God. He's my buddy, by the way, and in times like these I need him.

I have been bouncing from one post to another trying to make a point about horse power and torque, and what combos make what. Here is the skivvy, my friends,...

It really doesn't make a big difference how much power your "power plant" makes.

How fast you get around the track is all that matters.

Just get the power to the track, and race on.

I wish all much success this racing season, and have yourself a blast doing so. Be SAFE!

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racin78p
if it ain't fun, then don't run

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