check my engine builders cam choice
 

I am a little worried it is to radical canyou guys reasure or tell me he is crazy........
tappet lift 313 322
valve timing @20 int open close
49 84
ex 91 51

duration @ 50 int 276 ex 284
lobe lift .4400 .4200

gross valve lift int .748 ex .714
lobe seperation 110.0

old cam was as follows

gross valve lift .661 .668
[email protected] tappet lift 291 297
valve timing open @50 int open close
15 59
ex 62 18
Dur @ 50 int 250 ex 260
lobe lift .3890 .3930
lobe sep 112.0




it took me forever to type this

Re: check my engine builders cam choice
 

Is john force your engine builder:D ? tell us more about your motor,the cam seems humungous to me,obviously you must be running a large, high compression motor and your cam must be a solid roller. One of our in house cam experts will be able to judge it better but to me it sounds like a 7500rpm drag boat cam,Smitty

Re: check my engine builders cam choice
 

Did your old cam seem too small? What rpm's do you want your power to peak at? How heavy is your boat,what is your cu inch and compression ratio,without this info we can only make a W.A.G. but it still seems like a big daddy drag cam to me,Smitty

Re: check my engine builders cam choice
 

540 just over 9 and a half to one comp dart heads jesel roller lifters and stud girdels j and e pistons, h beam rods .....It seemed a bit much for me to....Peak rpm around 5800 50 6000

Re: check my engine builders cam choice
 

to big , and on a 110 you will need dry pipes

Re: check my engine builders cam choice
 

That cam is huge and will be a parts breaker.A cam that big in a 540 will rev to 7000

Re: check my engine builders cam choice
 

9.5 to 1 compression is not enough for that cam.
More like 12.5.

Thats a Drag Cam for sure.

Re: check my engine builders cam choice
 

what am i supposed to tell this guy if he is steering me in the wrong direction

Re: check my engine builders cam choice
 

Tell him you are the guy paying the bill.

Re: check my engine builders cam choice
 

thats more cam than you need or want with that motor, My motor likes this. @50 269-276, lobe lift402-406. gross lift 683-690. lobe sep.110 in cl 108. @50 26.5btc cl 62.5abc . ex 70bbc 26atc. These cams are easy on valve springs. These are solid roller with a 4-7 swap and cast gear, i had them done at custom cams in etta ms. 662-534 4881. Brian

Re: check my engine builders cam choice
 

Your OK , he's Crazy !:eek:

Re: check my engine builders cam choice
 

The man is crazy!:eek:

Re: check my engine builders cam choice
 

When I saw the cam specs, I thought it was huge, but thought it might be going in a 632ci or something. Even the old cam looks like its on the large end of the spectrum for a 540.

You have 2 of OSO's most respected engine builders telling you your builder is nuts.

Re: check my engine builders cam choice
 

You will need an ice axe to chip the snow off the lobes and a magnet to get all the broken valvetrain parts out of the sump. Jas

Re: check my engine builders cam choice
 

i dont know a lot about the whole cam thing, i can assemble motors but i dont know everthing, but this did seem a little extreme......The problem that i am having is that he paid for the camshaft and the gear drive.......A total of almost a thousand dollars......I believe he felt guilty for the problems i have had in the past when he was helping me............Now he says we are going to build you a (bullet proof thunper)...........I have the whole boat just about perfect,m paint next week,gauges,dash, interior,exhaust, the whole nine yards.........................I just want to have a summer with no problems...............

Re: check my engine builders cam choice
 

When an engine builder hears "540 CID and I want to be able to turn it 6000 to 6500" then the figures you have posted start poping into the engine builders head. Problem is in a boat you don't have the luxury of a stall converter, clutch, or mulitple gear sets and all of these are what the majority of engine builders get to take advantage of to get an engine to its powerband. Ever taken your boat engine to 5000 rpm and then drop the bravo in gear? Marine engine builders have the deck stacked against them in making power because of rpm limit, wet exhaust, and the need for an engine to idle at or below 1000 rpm to go into gear. A boat engine has to go from 900-1000 rpm to 6000 pulling on a set gear ratio.

The cam that has been selected will not work for your application. I would suggest having it sent back and re-ground with spec's more marine friendly.

Re: check my engine builders cam choice
 

i really appreciate you guys.......I am really in a pucked up position right know................I might just slide the cam back out and order a new one..............

Re: check my engine builders cam choice
 

You only get a limited boating season where you are.You wouldnt need any down time due to lifter and spring failure which will result from that profile.

Re: check my engine builders cam choice
 

guys as always you give me the good advice................Now is there someone locally i can send the cam to....It is brand new i imagine they can cut it down........MIchigan area buy the way....................I really dont care where it has to be shipped i just want it right...........

Also how about some other suggestions on what grind......`


I will pay for the knowledge pm if ya want to help

Re: check my engine builders cam choice
 

Try Wesco Racing engines, they're located just south of Grand Rapids in Jenison Mi. Ask for Dave Wesseldyk, tell him what you're doing, and what you want to do, and I'm sure he can give you some professional advice. He might even have something on the shelf there that'll fit your needs.
His shop # is 616-662-2250

Frank

So far, you've gotten excellent advice here from what I've read. Listen to it. It's your money, your boat, and your time that'll be down if you let this guy get his hands on your equiptment.
From what I've read about his ideas so far, I would'nt let him work on my kids bike.:rolleyes:

Re: check my engine builders cam choice
 

At least one person who would be one of the best for cam selection is Bob Madara "RMbuilder" of Marine Kinetics---he will get the right cam for you and your application. Bob has helped many on this forum with proper cam selection.

By the way, Dave from WESCO orders pretty much ALL his cams from Bob Madara for the engines he builds....and he builds some top notch marine engines and he isn't too proud or egotistical to ask for cam advice. He keeps ordering them from Bob from one engine project to another....must be he likes what Bob provides.

Now the thing is, is that your engine builder knows what it takes to build an marine hi-perf engine properly. That might be the next thing I would be concerned with.

Hope it all goes well for you. Phone numbers are below

Re: check my engine builders cam choice
 

nocigerette,
Do what Kaama suggested and call Marine Kinetics, aka Bob Madera, 586-772-2395. Tell him about the bind that you are in. He may or may not be able to regrind that existing cam. Make sure you have all the particulairs on hand about your engine, boat, intended use etc. He needs information. He will help get you where you want to be. He did a great job with my cam selection, and he is a great person. Tell Bob Whiteknuckle said "hello".

Re: check my engine builders cam choice
 

You start drinking at 10am??? :drink: Don't know who's phone number you posted above, but it isn't Bob's. Anywaym his correct phone number is 585-654-8583. :D :D :D

Re: check my engine builders cam choice
 

Nocigarette,
The cam your engine builder has selected for your application is a Comp Cams:
Part # 11-749-14
Grind # 47S 313R10

As everyone has stated, the cam is mismatched to your components. With a 9.5:1 SCR and the late IVO of this lobe you will be seeing very low cylinder pressure killing off virtually all your mid-range TQ/power. This profile, with 540 displacement, will make peak TQ ~ 5800 RPM and peak power ~ 6900 RPM. If you prop for 5800 RPM, this places your WOT at approx. peak TQ, negating the fat curve from peak TQ to peak power.

Idle quality will suffer due to the 100º overlap, making the boat difficult around the dock and hard on parts during drive engagement. The recommended spring package for this cam is the Comp 948/26082 Hi-Tech Drag triple spring, set up @ 332# @ 2.100” seat, with an open force of 949# @ 1.200” 686# rate. Those numbers are also a bit of a red flag regarding pushrods and lifers. Even if you do not RPM the motors these lobes will require serious spring to control a 150-gram valve. It would be impossible to put any cycle values on the valve train components due to the (NC) intake and (–3) exhaust lobes being run at prolonged RPM.

In regards to regrinding the cam I would suggest you contact Comp Cams directly for the most accurate answer. It is a 4/7 swap on a billet core, however without knowing the core/base circle sizes, it is impossible to know exactly what lobes can be put onto this core. 800.999.0853, ask for Chris Padgitt.
Hope this helps.
Bob

Re: check my engine builders cam choice
 

i cant say enough good about you guys thanks a lot.................

Ok.....You guys will think i am crazy but i ran that cam this year....First let me say that the boat ran 3mph faster than last year...The cam never broke any valve train parts.....With that being said now i have a huge tuning problem with the carb, i can not get it rite on top end or mid range but it idles like a kitten................

My question is ,,,,,,,,should i leave the cam in or should i due a swap while the motor is out and in my garage for the winter.......( carberator is going to nickerson )

I am not trying to sound arrogant about the cam working, i am still looking for advice.....Thanks a lot guys

It may have run even faster with the correct cam, tell us your final engine combo, performance info Rpm top speed & how much prop you turned. And why you are pulling the motor after one season ?

I pulled the motor because i am going to add a thermostate controlled oil system and wanted to check the mains and rod bearings...Unlike a lot of guys on here i use my boat every other day .....I put almost a hundred hours on a year....So if ya are trying to imply something DON'T......Read the posts about the rebuilding of my boat.....I am over anal about my boat and i check everything every year......If you are going to give advice i can use then post if not then due like your mom told ya growing up ( If you dont have anything nice to say don't say anything at all)

I'm sorry if you misunderstood my questions! I wasn't implying anything negative I was just trying to further expand on the discussion as to what cam may be better for your application should you decide to change it. Afterall, you avatar says 1974 magnum sport with too big of a cam.
I hope this clears things up!!

It is hard to exspress how ya feel while typing.....No sweat i'm sorry if i got carried away....

nocig,

I am staying out of the cam discussion.

I would like to say that I dont like guys pulling oil pans and bearings to "just check them". You can accomplish the same thing by getting a $40 oil filter cutter and opening the filter on every oil change, stretching the paper out and looking for any bearing material. If the filter is clean, leave it alone. Too much chance to mess something up by pulling rod and main caps and looking at bearings.

Just my opinion,

Happy 2008 to all :)

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Just did that all looks good,:party-smiley-004:

How due i delete threads............Just curious

2cents worth
 

nocig,the cam you have is a valve -spring killer.big lift and long duration are killers of the spring,not to mention more wear and strain on the valve train.just my 2cents worth.good luck with your project.