LUVTruck.com

Im not an engine builder by any means but I am at the point where I want to start doing more myself. Can someone explain what the numbers mean when looking up cams like on websites and catalogs.

this would be a great question for luvsadrag he probably knows alot about this.

I did some reading about this topic last night and I think I am more confused now then I was yesterday. The stuff I read basically said its a simple and then it got into numbers that made it look harder than chinese arithmatic and didnt really explain anything.

Here are a few sites with basic info on what the numbers mean. If you are looking for information on how to apply that information to an specific engine.... that's where the fun begins..

http://www.auto-ware.com/combust_bytes/camspecs.html

http://www.chevyhiperformance.com/techarticles/148_0505_cam/

You might want to figure out what you want the engine to do to start with. Are you going to drive it on the street, street/strip, primarily at the dragstrip? Figuring out what cam is only one aspect. The intake, carb, exhausts system need to work well to get the most out of the complete package. And with more radical the cam is, the aspect of using a stall converter will play in to the equation.
What helped me out was to order an Edelbrock catalog. They have complete power packages that you can look over and they'll advise if certian packages require a stall converter and how much stall is needed.
With this info as a guide, you can compare the cam specs and see what intake and carb setups will work cleanly.

_________________
Previous setup: 4.1 Buick V-6/TH 350
Current setup: 400 Small Block Chevy V-8/TH 350
9" ford rear end/short bed/blue
What do Water, Electricity and Humans have in common... They all travel the path of least resistance.

I know what I want the engine to do and the tunnel ram and the heads seem to work together all right but I think it could use a little bit more of a radical cam that will work from a mid to higher RPM range.

RoadshowBob thanks for the links its pointing me in a better direction than I was going.

its all about what your goals are for the motor. street driver, towing, street strip. full race. it also depends on what else you are running or plan on running. what rear end gear, what transmission, what converter, what compression.

_________________
1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

I got the motor together and running with the cam I had in it and thought would work ok for the tunnel ram. I plan on making it kind of like a weekend warrior serious street go to the strip when I want to. Its a 327 with 2.02 heads weiand tunnel ram and 2 holley 450 cfm carbs. The rear end that is in it now that is coming out soon has 4.37s in it going to get changed out with a ford 8.8 with 4.11s. I dont know the exact stall stall speed of the converter yet since its only made one short trip of about 3 miles. I went to the comp cams website earlier today and filled out the cam form with all the little details to see what they recomend. I figure since its a small motor with a tunnel ram its going to have to be twisted pretty hard to get the horsepower out of it. so I am thinking around 235* of duration with a some what small amount of lift. Like I said earlier cams are like chinese arithmatic to me and from all the confusing stuff i have read this is my take on it. I could be way off in my way of thinking so it wouldnt hurt to get another opinion.

what cam is in it now?

_________________
1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

what is the current cam (lift and duration wise?) giv me a part number and cam company if possible.
what is the compression
have the 2.02 heads been ported at all? If so what do they flow?
forged piston steel crank motor?
what intake and carb?

How fast do you want to go?
Normally aspirated or spray it?
If spray will it be a dedicated nitrous motor or do you want to run all motor with an occasional surprise for the street racers that think they have u all mapped out?

I can pick out an "off the shelf" grind really quick based on the info i asked about above but it gets really tricky when you start going for custom grinds. For that I consult a guy that i feel is one of the best and most intuitive cam grinders around.

_________________
1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

Well first of all I got the motor from a friend that use to build my circle track motors. He built the motor I have in my truck for a boss hoss motorcycle and totalled the motorcycle with less that a 100 miles on the motor so I got good deal on it. The motor was built about 3 years ago and has been sitting on a stand pretty much all that time. Since then he has built a lot of motors and cant remember a whole lot about it. The Block casting numbers say it came out of a 68 camaro. The heads were changed I dont have the casting numbers in front of me but from what I have got off of mortecs website the heads are have 2.02 intake valves were made in 1970 and have an X at the end of the number. I remember it also said something about larger ports or something to that nature I cant remember exactly it was a while ago when I checked. I also remember it said it had 75cc combustion chambers. Thats about all I know about the heads. The camshaft that is in it now is also kind of in the grey area I dont know anything about it other than it doesnt have that big radical sound to it. I was told the compression ratio was 9.5:1 the crank is most likely to be stock not sure about the pistons. The intake is a weiand hi ram with 2 holley 4160 450 cfm carbs. The intake that was on it when I got it was a weiand team G and it didnt come with a carb. The guy that I got it from said it was suppose to put out about 380-400 hp the way it was when I got it. I got the motor about 8 months or so ago so all the things I was told about it are kind of in the back of my mind and I cant remember all the particular details. I dont plan on using nitrous anytime soon and if I do it wont be on this motor. I want to go as fast as I can with out getting myself into major debt and since this isnt a sponsered race car deal like my other cars have been Im kind of at the mercy of my wallet that gets thinner and thinner everyday but I would probably be happy running in the mid 11s low 12s in the 1/4 to start out.

234 244@ .050 .488 .510 lift is a very good street cam with a ratical idle and totally screames after 2500 rpms

What is the maximum amount of lift a stock or relativly stock small block can handle before things start breaking or creating anyother issues? Im not sure that alot of lift would be good for my application but if I decide to try something stupid I really dont want to create more problems. One of my friends was suggesting I go with the old Duntov grind that was used in the 327s back in the day. Im sure there are better choices than something that was used in the late 60's I just dont know where to start. I still havent heard back from comp cams after filling out their cam help form. 234 244@ .050 .488 .510 lift sounds about where I would start. I would rather just do it once and be done with it.

I put this cam in my buddies car last year (monte carlo ss) and his car was the original 350 with bone stock heads and that cam Really woke that car up but soon after he had to put a 2200 stall so he could drive around town comftorbly. you dont have to run a stall converter if you would just idle it up wile it is in nuetral but that would be up to you and to get the most out of the cam i would recomend a stall converter.


(this cam is mean on the street and weekend drag strip use)

stock diameter valves allow for a max of bout .500" -.510" lift. I've shimmed a head with a chevrolet brown spring and run a .525/.525 lift and long slot stamped steel rocker arms that we massaged even more with a dremel but thats really pushing it. depends on what your head volume and flow are. overcamming will make a for soggy motor. if they're 461x heads all stock no porting then .480/.480 with 280*/280* adv (thats about 230ish at 50 by most cam manufacturers) with a 108 center will be about right especially with a 4speed. that will be a nice choppy idling cam and will work well with a nearly stock bottom end. 2500-6500rpm and will put you in the 375+ hp range. those heads really need to be at least pocket ported to make anything in the half inch lift or bigger range work to its potential. Hope this info helps with your cam selection.

_________________
1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

Today was the first day of the luv meet here in redding bummed me out it rained and I couldnt drive my truck. Maybe tomorrow the sun will come out and let me drive my truck and get a better idea where of what its lacking. I havent really got a chance to drive it yet. I know it didnt want to run very good at low RPM and I expected that with the tunnel ram I just dont know how good I should expect it to run under 2,800 RPMs. The friend that tuned my carbs said it needed a bigger cam with more duration so I guess Im kind of taking his word more than anything right now.

This what I got after filling out the comp cams questionaire:
Cam Spec Card Inquiry
PART NO. 12-242-2
01 INTAKE MASTER 5443
02 EXHAUST MASTER 5203
03 ENGINE CS XE268H-10
04 GRIND NUMBER CS XE268H-10
INT EXH
05 HYDRAULIC Y/N YES 14 DUR @.050 224 231
INTAKE EXHAUST 15 LOBE LIFT .3180 .3200
06 VALVE ADJUSTMENT HYD HYD 16 ROCKER RATIO .00 .00
07 MAX GROSS VALVE LIFT .477 .480
08 DUR @ .006 TAPPET LIFT 268 280 17 LOBE SEPARATI 110.0
18 ADVANCE 4
09 VALVE TIMING OPEN CLOSE 19 VALVE SPRINGS 981-16
@ .006 10 INT 26 61
11 EXH 72 27 DATE SETUP / /
12 THESE SPECS ARE FOR CAM(S) INSTALLED
@ 106.0 INTAKE CENTERLINE


Hadley Owens

Comp Cams Inc.
Tech/Sales Support
howens@compcams.com
901-795-2400 ext. 724

they're being on the conservative side like most cam companys do. that cam will work very well and will idle a little rough like you want but ask them what they think about the 480/280 cam (its a very popular off the shelf grind). ive put one in a motor exactly like yours except it was a 350 and it was in a heavier car (70 1/2 Camaro) the thing absolutely ripped even with a 3.08 gear. Make sure you stress that that you're running a 4 speed and tunnel ram. the 480/280 cam will pull bout 500-700 more rpm on the big end than the one they recommended which is what you need for a short stroke motor with a ram and deep gear. Your manual trans will also make the a 108 or even a 106 lobe center liveable on the street(your idle will be beyond choppy)

_________________
1978 LUV Truck 2WD
450 "Small Block" Chevy
3.70 Ford 9
28x10 Goodyears

are you saying tell them I am running a 4 speed even though I am not?