Cam specs....opinions
 

I'm building a 509, 088 heads, gasket matched to a dart single plane intake, short radius cleaned up and a little bowl work, topped with a 850 Holley, roller rockers, gen 6 block. Motor has steel crank, dimple rods, je flat top with 3cc valve relief. I'm going to shoot for 9.2:1 compression. Gil exhaust with dry risers extended to the transom before the water dumps into exhaust.

A buddy has this cam he didn't use and was for a very similar build to mine for his boat. It's a cam motion grind.

236 in duration
244 ex duration

629 in lift
612 ex lift

112 lobe sep

108 in center line

8620 core

I was planning on going with bob or young performance, but came across this and I can get a good deal on the cam.


Any opinions on the numbers?

Boat is a velocity 280 with b1

I'm shooting for 600 hp or as close as I can get with the parts I have. Heads aren't in the budget at this time.

Thanks in advance.

Thats pretty close to what I had in mine when I had the 088's on it. 509ci, same JE pistons.

236/244
650/603
112 LC

Made 580/605 on dyno

Good luck

imo,that cam will work good with the rest of your parts.

Seems similar to the crane 741 cam. Works well in a 509. Should peak in the 5500-5800RPM region. Good luck

Sure you don't have those lift numbers swoped? If they were the other way it would be almost the exact same cam as the Crane 741, 236/244, 610/632, 112. Crane advises 10.5:1 or more compression with that cam but you will be limited from anything like that with iron heads. IMO for you to see near 600hp your going to have to really spin that thing up there. May not have enough downstairs to get that big of a single engine boat rollin that fast with out under proping it.

Didn't catch your post there before I replied Thunder. Was thinking that cam in a 28' single would be more at home in a 540+.

A buddy of mine had that cam in a 509. Merlin iron heads, flat top pistons, dart single plane intake and 800 holley. Right around 600HP/600Ft lbs. I lost the dyno sheets but I wanna say tq peaked about 4600, and hp around 5700. Ran strong and sounded good.

Sorry pickle, we must have been posting at same time.

That cams not far off from the 525EFI cam, works ok in a 502...The 088s leave a little to be desired but should do ok....

Thanks for all the comments guys! It sounds like this cam should work ok and get me close to the 600hp goal I have. I agree the heads leave power on the table, but they just aren't in the budget to get the boat done for spring. I wanted to go with a set of afr 305's.

I'm assuming this cam will work ok when I do change the heads?

One more question is about the lifters. These lifters only have 60 hours on them, but not sure if they will work with this size cam. They are the factory lifters that come with a 502 mag (gen 6). They don't have the link bars. I realize each motor may be different, but were you guys able to run the factory style lifters or did you have to go to link bar lifters?

This is a single engine 28' boat. I figured I would have to spin 55-5800 rpms.


Again, thanks again for the help!

About the lifters, well I heard the factory lifters don't like that much, I got the Lunati cam damn near the same, 234/244 .629/.612 114 LSA 112 ICL and I called Lunati for the recomended lifters because I wanted to go with the cheaper street rollers with the link bar for $300 and some change, I told them what I was going to use it for and they suggested I go with the High RPM ones that are stronger and can take a beating, but they were $600. Well either it was good advise or a sales pitch, I went with the $600 ones, I guess for me it's cheap piece of mind. Just my 2 cents!! Hopefully the motor people will give some insight on this. Thank to the guy's that have given me advice!

Same lifters I am running. Endurance lifter rated for 6600RPM continuous. They also have a High RPM version, for 7000+. I was told by several big marine engine builders to use the endurance lifters, as that's what they use.

I have a buddy running the morel street lifters in his engines. No issues with them so far.

PS. The lunati, howards, PBM, are made by Morel. I don't think its snake oil. Lunati gets the lifters from morel. I doubt the sales/tech guy is making out by selling us the more expensive lifter. Their profit is probably very close for either set of lifter. Im sure if you called them and told them you were building a 900HP blown deal, they'd recommend their forged crankshaft and not their cast crankshaft. But if you called and told them you were building a mild 400HP big block going in your molestor van, theyd suggest their cast crank would be suffice. :bunnydance:

Lifters it is then.

Thanks

I have a similar cam in a 524 with the AFR 305's with the CNC'd chambers and bowls at 10:1 compression. I did a gasket match and runners myself. I went with the Morel lifters, but I have a set of Crane 13532's with 50 hours on them that I would let go cheap. I have a 280 also, so far I've hit 90 with 4 adults and a full tank. Still have a lot of tuning to do hope to be in the mid to upper 90's when done.

Give Bob M. a call for a set of the Morel lifters. Pretty sure he could get you in at or under the $600 mark. You will also want to check your valvetrain geometry and run the correct length pushrods. Don't cheap out on the pushrods on a cam with that much lift! If they start flexing on you at high RPM's it could set up harmonics that could adversely affect the rest of the valvetrain. You can find yourself heading into all kinds of bad situations like lifter loft, etc. Talk to Bob - he is one of the best sources of information out there, and he is the type of guy who is willing to take the time to talk to you on the phone and steer you in the right direction. Wish I had talked to him when I built my engine the first time!

Thisislivin, that's basically exactly what I'm wanting. At the point I change the heads I'm hoping for 90. I talked to Steve stepp and he said with 600hp or close to it I should be in the 85-87 mph range.

What's wrong with the crane lifters you have? Are they not heavy duty enough? I'm Interested in picking the lifters up if they can work for me. Pm with price and details.

I may call bob this week as I'm getting real close to getting all my parts.

Thanks

The Crane's might be OK if they are the long-travel lifters (for GM style Gen VI dog-bone arrangement) and they have the larger .750 wheel on them. Everything I have read seems to indicate the Morel's are kind of the gold standard, but I have heard that Isky makes a good product as well. Can't speak for the other brands - no personal experience with them.

Thanks budman. Ill have to check out the details to make sure they will work.

That’s the correct number for that combination with the OEM heads.

That will depend upon the base circle of the camshaft. When attempting to utilize the OEM style horizontal tie bar (dog bone) lifters you will need to mock up the engine to finish spec and check both the intake and exhaust.


The advice they provided you was accurate. Morel makes 3 levels of lifters in the .842”, hydraulic roller configuration.
The “Street” lifter is a cast body with a .700” wheel and has a place as an OEM replacement lifter. It is not designed for longer duration (23x+) camshafts and the valve spring rates, seat, and open forces required in a performance marine application.
The performance lifter has a steel body with a .750” wheel and is “good” to ~ 6500 RPM and 200#seat/500# open.
The High RPM lifter is a billet body lifter with a .750” wheel which I have personally seen run well in excess of 7000 RPM.
The .903” version will feature a .810” wheel, which combined with a 55mm+ core will open new opportunities in hydraulic roller cam development.


I would caution you regarding the economy of running used valvetrain parts, or OEM components that are outside their design specification, in marine performance applications.
Regards,

Bob

That Velocity must be a good hull. I'm impressed that you can go that fast with that setup. You are faster than me running a 509 & whipple, but you have way better heads, cam and more compresssion. I would love to get mine in the 90mph range.

Thanks bob. I'm close to ordering parts and will probably call and order with you so that I know I'm getting what I need.

It's seems to be a very fast hull (pad bottom). The owner of velocity told me that the boat runs a solid 84-85 with a 525efi. I felt that was pretty good. I haven't run mine yet, I bought it with a hurt piston and didn't want to go back stock. Which leads me to this build. My last boat was a Baja and it only managed 63-64 so I'm excited for the faster hull.

Nothings wrong with them, I had them inspected when I had the motor apart by Ron at Dynamic Speed. I boat on Lake Huron and it's 30 miles to the nearest anything for me and I'm not afraid of the rev limiter. Like I said I had the motor apart and wanted to do this once and be done. I had a perfectly good set of GM dimple rods too that I swapped for a set of Eagle H-beams. The lifters are for a GEN V block. Tell me what they're worth to you, my wife would be happy I sold anything after she saw the price for the rebuild.

Just saw this, I have a set of JE pistons at 4.560 and a set of GM dimple rods that have 50 hours on them. They are like new, they're flat top and -3cc for Valve reliefs. They gave me 9.1:1 with my old 117cc heads. I'd let them go cheap too, I can give you the number of my shop that did all the tear down and machining and they can give you a report on them.

The best part is cruise speed is 55-60 and I get 3mpg, I can cruise a couple of weekends on a single tank and my trips are usually a minimum of 50 miles and I may make a couple of those each day.

Here's what I found on the Crane site - The retrofit vertical locking bar lifters are machined from 8620 steel billet, heat treated, and assembled at our own facilities. Precision fit plunger assemblies are used to provide proper bleed-down rates, permitting high RPM use in properly set-up engines. The additional inherent strength of the 8620 material also maintains greater stability in the lifter body, permitting more consistent operation in very high spring pressure and high RPM applications, by keeping the plunger to body clearance consistent throughout the operation range.
Retrofit lifters also utilize our latest Monel pin and retaining flange assembly to attach the guidebar, providing superior long term durability.

How does that pad bottom affect the ride in rough water? Usually, there is a tradeoff when you go to a flatter hull for more speed versus a deeper vee that cuts the water.

I find that the velocity likes speed, if you try to go slow and crash through the waves you will get beat up. The trick is to sync your speed with the waves. I have found that in 2' waves you better be doing 55mph or you will get pounded. I've done 3' waves at 60 and the ride was pretty good. Where it gets tough is when you have waves from multiple directions or reflections off of opposite shorelines. In Lake Huron there can be a storm 100 miles away and you could have a sunny day with no wind and you will see rollers at 2' - 3'. I will say this, after last summer I am looking at a 39', we had mostly 3' - 5' almost all summer with some 8' thrown in for good measure. I tried going out in that stuff and after launching the boat 15' off the water I came to my senses and headed back to the harbor. My wife told that she could see the bottom of the outdrive over the top of the rock wall of the harbor standing at the launch.