Engine and Cam experts..!

I bought a beautiful boat Offshorer Montecarlo 30 (check on web for pics) extremly rare in the US but mythical in the mediteranean around Monaco specially.
After carefull inspection of the engines all casting numbers I discover that my reverse rotation engine is a very old 454 from the 70's probably rebuild whereas the standard roation is recent 502 GenVI 2000's.
I am struggling for months to find a 502 reverse rotation but does not exist so decided to build one butthe tricky part is to find reverse rotation Camshaft: only found ine source at MELLING.


I believe that my 502 has Stock Cam (P/N : 12551622) Stock cam and holley750 produce on the 502 415HP
Specs
- 224in/224ex duration
- 483in/483ex Lift
- 109in/122ex Center Line
- LSA of 115,5°

For now I only found Melling perf cams for 502 they produce both standard rotation and reverse rotation so I could upgrade my exisitng 502 that is very good condition. and build a new one with the same cams: reverse 22218 and Standard 22217

Melling Specs (P/N : 22217standard& 22218reverse)
- 289in/301ex duration
- 460in/476ex Lift
- 110in/120ex Center Line

So my 3 questions:

A/ you can see on the Meeling the lift is slightly reduce 2 to 5% less But the Duration is significantly increased 30-35% more.
So what would you expect as out on HP and Torque??

B/ what would be your recommendation which carb to get the optimal result? for now I have an 850 Holley but considering a quickfuel 750 or 850??

C/ does anyone know any other source of Reverse rotations Cams other than melling?

Thank you for any insight.

Ivan

Stock Cam
- 224in/224ex duration at .050" lifter rise
- 483"in/483"ex Lift
- 109in/122ex Center Line
- LSA of 115,5°

Those Melling 22217/22218 cams are smaller in duration and lift
http://www.melling.com/Portals/0/Cat...-13-140049-450
- 214/218 duration at .050" lifter rise
- .460"in/.479" lift
- 110in/120ex Center Line
- LSA of 115

So, good thing you posted, as the info you had was incorrect

Thanks SB
I reported the SAE duration so guess it is my mistake!
It sucks i was hoping to get more power it seems that with smaller lift and shorter duration this will not happen!!!

So any other source of reverse rotation cams?? As at mellibgbit Sean's that the only pair are 22217/22218

Thank you in advance

I would think that cam motion could make whatever you want.

http://m.cammotion.com

Thank i will check with them

Any luck?

They did not have the core for reverse rotation, it seem often to be the limiting factor.

But if anyone needs a reverse rotation I found guys in NC http://www.camcraftcams.com/ they said they have all steel cores and masters for reverse rotation stock camshafs.

Did any one use them before?

let me know ?

Don't know if Bob Mandra would do a reverse, but why do you want to stick with a right hand motor? Just my opinion so please excuse if I'm off base, but; if you were doing a full up restore to original then need to stick with the 454. But since your going with 502's why not put some Bravo drives on and not mess with the right hand rotation?

Just to update you all
Got a new GM automotive 502 450hp (6900$ + free delivery)
1/ Marinazed it:
- New head gastkets
- Replaced freeze plugs for Bronze Plugs
2/ Reversed the rotation
- Got a reverse cams grinded at "Camscraftcams" identical to the one on the other engine (stock 502 genVI roller: 224/224 483/483: 370$)
- Pistons were symetric no need to reverse the pistons (that was lucky saved some work).
- New Mallory distributor same as my existing on the other engine new old stock
- Found reverse gear for mallory (that was lucky too new old stock 25$!)
- Replaced Crankshaft seal for a flat seal (when reverse seal with lips spit oil out !!!)
3/ Cranked it: fired with no problems so far

Total Engine cost $6900 + new cams $370 + marinisation work and parts $500 = $7770
+ mallory $350 + Holley $500

Ready to be installed !

keep the reverse cam, gear drive and dist from the tired old 454. ya never know...