hello im new to the forums and have a few questions on a projuct im building.
im currently building a 434 ci small block chevy(400 block bored .030 over and with a 4.000 stroke. it will have a complete eagle rotating assemblily with 72 cc dart platnum iorn heads. this is the farthest ive gottem as i done know what camshaft and intake carb set up to use on this engine. it will go in an 81 1/2 ton chevy truck and im hopping to make 500 hp and 500 ft lbs of toruqe. the truck will get driven alot but i want stupied amounts of horse power to beat the local rice and such. any help will be apreciated.

cheers

brandon  

When you start talking about camshafts there is a wide range of what you can do. There is alot of factors when you choose cams, like trans, gears, intake, cylinder heads,carb etc.. I can see you want to make 500 h.p. so you will have to go with some kind of roller cam to accomplish this. You should really call comp cams or crane cams tech line they seem to be really helpful on choosing camshaft.  

First off, are you going to try to fit this setup in a GM production block? Secondly, information on the vehicle would be a nice start to figuring out anything. Transmission, converter (if any), gearing, tires, etc. Also, are you using the 200, 215, or 230cc platinum heads?

I second the recommendation of a roller camshaft, preferably a solid roller. It's the best for outright horsepower and it eliminates any possible flat-tappet break-in problems. Your goal can be met with a healthy solid-flat tappet fairly easily but I imagine since this isn't you average small-block Chevy there's no reason to cut-back the funds on the valvetrain.

The engine will probably want the available plenum volume of a single plane intake. When most aftermarket single planes are meant for engines around the 350-383 cubic inch range adding another 84-51 cubic inches will probably "max-out" the system.

I noticed you said this truck will be driven often, how often is "often?" This is an important factor to part selection as well. All in all, there's a lot of missing pieces to the puzzle since this sounds like a dedicated project you better get the pieces together before trying to make a picture out of it...  

okay thanks for the help guys. ill be using the 230 and as is for the other specs it will have a 12bolt rear with 373 gears and a posi the trans will be a 700 r4 built to handel the power. the tires will be 275 bfgs and then 275 et radals. it will be driven during the summer and when its nice out.

cheers

brandon  

if funds are limited, you can use a flat tappet cam as long as you follow the manufacturers brek in procedures to a T! id go with a solid,550-580 lift and aprox 250 degrees of intake duration at .050".,exhaust duration around 260 degrees at .050" and a lobe seperation angle of 106 degrees to build lots of mid range torque.as for the induction side of things,a Super Victor intake and an annular discharge 850 Mighty Demon would fit the bill quite nicely.500 hp should be a piece of cake with this combo.if in doubt,call the cam manufacturer and they will set you in the right direction.hope this helps and good luck.  

Wow, don't give us too much information. Now that we know it's a fair-weather car we should be able to give a cam recommendation...

"bigcam406" is making a pure speculation. A 250-260 @.050 cam is awfully large for pump gas compression, not to mention 250@.050 on a 106° will make about 8" of vacuum at idle, and that weak signal will make power brakes awfully weak.If you cammed an engine with that much duration and have only a stock converter the car will be a dog and impossible to drive. We know nothing about how this is really going to work, so there's no since in trying to help.  

first of all, im speaking from experience,these are just ball park figures.remember,81CT wants a stupid amount of horsepower for his truck.the recommendations ive laid out will work perfect for a pump gas motor,as i have built a similar combination like this(the only thing different was i used Brodix Track 1 heads)a cam similar with these specs will work well,as the amount of overlap will thwart off detonation with his iron heads.secondly, a 4 inch stroke will tame the cam even more as more stroke for a given duration,the less radical the cam will be.like i said b4,call a cam manufacturer of your choice and give them the details and they should set you in the right direction.  

I can't believe you think you're speaking from experience. You have no experience with the engine in question, you don't even know if this engine will be using a roller or flat tappet camshaft! You have no clue if this engine will have 9.5:1 or 13.5:1 compression, like I said, all speculation. I say there's no point in camming big for insame amounts of horsepower, or whatever you call it, if you can't use it. 3.73's mixed with a 700R4 is not going to be a quarter mile king so you have no idea how large of a converter this person wants to use. An engine that pulls 8" of vacuum is by no means tame, no matter if the stroke is 3.75" or 4.0" if you have a 2000 converter this engine will need to rev 3000+ over the flash stall just to make peak torque (if you cam large that is). I just believe in balancing a combination, that's all, I see you just believe in building a big motor and putting a big cam in it and hoping that it works...

Sometimes I can't believe I help around here.  

the engine will have 11.0:1 comp ratio and the more i think about i might have to go to a th400 inorderto make a fun combo. but i love to drive my truck so id like to have overdrive on it so i can crusie and have fun with it. and i need to have decint vacumas i have power breaks right know. i can use a vacum canister and a pump if nessacery but i would prefer to no have to you it. te truck right know has 3 73 gears in it. if that helps at all  

the combo i built is in a street 70 nova,and runs 10.90's on pump gas on the motor.enuff said!  

I know you think you're pretty special for building a fast car but this kid won't, can't, and doesn't want to run 10.90's. Try giving advice that actually applies...

To "81CT", the extra information helps a little. It's great that you are going to zero-deck this engine but 11.0:1 is really pushing it in the compression department. I say go with a dish piston and make it a little more safe. If this is going to be a "fun" street-machine you can't cam huge anyway, and especially if you use a tight converter in a 700-R4 you are very limited with cam selection. This engine will not be a horsepower king because you simply won't have the rest of the combination around it to make it work but it's the sacrifice that has to be made to actually drive it frequently on the street...

I think you should probably look at Comp PN 12-433-8. This should have plenty of vacuum and fair street manners but it should have a 2800 or 3000 converter as well.

I know that cnc-motorsports has some rotating assemblies with Mahle dish pistons for a 434. This might be a little pricy for you but check it out.  

to "81CT",if you want a daily driver,get rid of those heads,too big port volume (230cc),dart website has the specs on those heads,check it out,for competition engines over 400ci. and 7000+ rpm.....a hydraulic roller that gibby recommended wont suffice.if you want the best of both worlds,go to a smaller port volume (215-220)and dished pistons,you will still have adequate compression for pump gas ,and then you can still be able to drive it everyday.the reason why i recommended those specs is what you said in your original post.you wanted a lot of hp to pound the ricers,so i figured you wanted a max effort street truck.seems that you want your cake and eat it too, so call your preferred cam manufacturer and see what they say.  

okay thanks guys and i thank you for the help with this combination and i was looking o day and ill place a 2800-3200rpm stall converter in it. the truck wont be a full daliy driver just during the summer months and when its nice out. i think ill give comp cams a call next week some time    

your quite welcome.do me a favour and post what comp cams recommends to you.im very curious as to what they will tell ya........  

I second the opinion to go to a smaller port volume but 10cc's isn't much of a difference. If the port length stays the same the average cross-sectional area would go down about 6%, which theoretically lowers the powerband 400 rpm. An 195cc AFR eliminator head would probably work wonders but maybe I have a tendency to be wimpy and build everything too mild...