Solid Roller Cam Choice
 

After speaking with most of the major cam manufacturers, I've come up with two grinds what I feel are close to what I need for this motor. I'd appreciate input from you folks who have experince with this type combo. Thanks.
@50 @50
Gross Lift Int. Exh. Dur-Int. Dur.-Exh. Centerline
Isky: .650 .654 282 288 112
Crower: .707 .700 270 278 112

The application is a 500 CI 8:1 Static Comp. non intercooled blower motor, 8 pds boost. 350 cc runner Canfield Aluminum Heads. Stainless Marine Exhaust 4" wet and no mufflers. 4000-4500 Pd boat that needs to still pull skiers, haul ass at river and travel in ocean 35 miles out or so and back reliably. Thanks for input folks.....

Cam grinds look good, but I don't think the wet exhaust will like the cams much, with them cam choices, you will need to run dry pipes, or you will probably have water reversion probs. just my .02
John

Thanks, I agree however My exhaust drops well over 14" b-4 the water enters the exhaust stream.

dam that cam is bigger t han my 598 ci im ronning 254 n260 575 575 easy on valve train but will be going larger this fall thats alot of duration for pulling skiers i think leaving alot of tourque down low maybe im no expert by no means though

Are you blown? I ran normally aspirated last year on the same motor 612 I & E lift. 240 & 245 Duration on a 112 centerline and is way too small for my now blown application...

I like the Crower. We had a Bullet cam with I697, E 697, 262 and 272 duration. Pulled like hell on the big end.

Me too. How was it mid range? Any cruise problems? Idle behavior? Thanks.

im sorry didnt notice the blown part my bad !! continue on told you i was no expert.

All good mate!

I talked with Dave Crower and gave him the specs for the canfield flow #'s, he changed his specs on the design to the following:
@50 @50
Gross Lift Int. Exh. Dur-Int. Dur.-Exh. Centerline
Isky: .650 .654 282 288 112
Crower: .694 .723 267 276 112
Crower Adv- 299 310
Input.....................?

Also, he wants to change the firing order for a 4,7,3,2 switch.
What about that also?

Feel free to give me a call. We build many SC marine engines per year and have proven custom cam grinds we have designed. The cams your looking at are too big in duration for your app. (216) 398-8500

Dean Gellner
Gellner Engineering Marine Power

I am running one of Crowers cams in some 598 8-71 blower/intercooler/Canfield motors. Have the 4 cyl swap. 106 Int c/l, at .050, .408/.402", 260 I, ?E (error on card), 110 lobe sep. Also set up with the larger journal for lifter life. Honestly, I am not really sure if the cyl swap deal was worth it. Dave certainly likes the $ he gets for these though. In my app the specs work fine.

Gellner is da man...

John

Thats a pretty big stick your puttin in there....I'd back the duration off some aswell ...like bob has, I'd go with a lobe sep of 110 it will help you clean it up on the bottom...you'll be happier when playing with skiers....

Yes he does, to the tune of 450.00.

What is the boat and it's Use?

He says the cylinder swap is primarily to make a positive effect on the harmonics not so much for power.

Have you ever had a reversion problem with the 110 lobe centerline how does it affect your idle??

Those cams are way too big for your application....almost as big as I ran in 632" NA pump gas 900HP motor!!. Duration's were very similar, but I ran more lift...on a 114 and 115... FYI, Peak power was ~6600 with that cam. How many rpm do you plan to turn? 4/7 swap is cool, but you need to be turning 6000+ to take advantage of it from a power standpoint.

IMO you need to have durations in the mid high 250's and mid high 260's range, your lift is about right, and get to a 114 C/L.

Do not run those monsters with that small of a motor...it will be a nightmare for you from a lot of standpoints...reversion is a very real possibilty and your motor will not idle below about 1200 rpm.

As far as the reversion issues go, my exhaust drps 14" b-4 the water enters and then it's straight out the rear, is that still a problem with reversion?

As far as the centerlines @ 114 Vs 112, oe even 110, what would be the difference there? Thanks.

I'm just not sure about reversion in your case...and I am usually pretty aggressive about telling people to NOT worry about it.....I can't make that call...but that is a HUGE cam for a 500" motor and if you are thinking 112 or 110 the problem becomes worse. There are lots of reasons (some more technical than I probably know) that you should be thinking 114. (A) most blower grinds for marine are on 114...think about it, if you are forcing the air in the motor under pressure, overlap and scavenging are not as big of a deal. (B) motors with less overlap idle better.

Those are the main (2) to be thinking about. Talk with Dean Gellner, Dean Nickerson, Bob Madera, Teague, etc for all the other reasons...and their reccs... None will be even close to that big, I guarantee it....Make sure its a marine person...there is lots of knowledge at the cam companies...but most of them have little if any experience in a marine environment where wet exhaust, idle quality, etc matter....

FYI, many 502-509" motors we have built and run with (aweful) stock 500hp heads, roots blowers, utilize crane 651 hydralic roller..which is 244/[email protected] .632/.632" on 114. The idle with this cam is pretty nasty...its a big cam for a 500" motor...let alone what you are talking about running. Your heads are much better than stock and you'll need less of a cam split to "crutch" it. Peak poewr on the above set-up is 6100 rpm and that's hydralic roller.

Just got off the phone with Teague....... That is THE LAST CALL I WILL EVER MAKE TO THEM!!!!! What a co88cky bunch of SOB's! If you aren't building something over 650 CI they have NO time for you to sell you parts or otherwise. They only sell "premium engine stuff" OHHHH, so sorry to call!!!! Oh yeah, apparently I'm a "car guy" and according to this parts guy, and don't understand the performance boating market! I've only been building and rigging my own boats for 20 years! Unbelievable!

That's real similar to the cam I'm running on my 454 mag efi with Dart 325's and a Vortech supercharger. It dynoed at 730 hp at 5600rpm with 9.8 psi. I'm propped to run at 5200 rpm at 669 hp, and my cruising hp is 510 at 4k.

Ghittner, I would be looking at no more than 630 ish lift, and I know you recently bought those heads, why didn't you go with the 315 Canfields? Your heads are huge, the cams your looking at are huge, that's no problem if you want to crank it up to 7k but your post said you want something reliable and that you can ski behind. The smaller heads will give you more low end hp and torque. The bigger heads wont show you any thing until your aboove 6k.

Maybe you looking for more than 700hp or so? If so more cubes will get there easier. :boat:

All done and ran the Crower BIG cam and I couldn't be happier.... This motor grunts out of the hole like there's no tomorrow and the top end is unbeleivable. As far as idle, 1150-1200 out of gear and 650-700 in gear. Dock manners are excellent and it has way more horsepower across the full powerband than I could have imagined. Pulls tubes and skiiers all day long. Absolutely no sign of reversion. All the stuff I was afraid of with this large a cam never came true, It runs Perfect.

Crower:@ 50- Lift-.694 Lift-.723 Dur 267 Dur 276 L/C112

All done and ran the Crower BIG cam and I couldn't be happier.... This motor grunts out of the hole like there's no tomorrow and the top end is unbeleivable. As far as idle, 1150-1200 out of gear and 650-700 in gear. Dock manners are excellent and it has way more horsepower across the full powerband than I could have imagined. Pulls tubes and skiiers all day long. Absolutely no sign of reversion. All the stuff I was afraid of with this large a cam never came true, It runs Perfect.

Crower:@ 50- Lift-.694 Lift-.723 Dur 267 Dur 276 L/C112
Just Wanted to udate still runnin strong Skiiers band tubers @ 1800 RPM and running up to 6800 RPM top end IDLE NO LOPE AT 1200 rpm..STILL PERFECT YEARS LATER !!!!Thank you CROWER!!!!!