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!