Dead cylinder??

[RCSConstruction]

Re: Dead cylinder??

My recommendation is: if the rv cam is the wrong match for your engine/app, just buy one that is. A new flat based hyd cam and lifters will be around $150 vs $600 to convert to roller. (steel cam, roller lifters, push rods, spyder and retainers, timing gear/chain, cam retainer plate, special fuel pump rod or elec fuel pump, and possible distributer gear) For our boat engines, the main advantage of a roller is less cam wear. While that is true, I wonder if the reliability of the roller lifters are less than the flat based. I've seen a few posts on roller lifter problems.

What are your thoughts on a stud girdle?

 

[Tail_Gunner]

Re: Dead cylinder??

Time for Bondo or Don to chime in here.......

 

[Tail_Gunner]

Re: Dead cylinder??

Thanks for the info iJohns. Your input in this thread has been very helpful.
I got my mind made up that if/when I pull another stud, I am taking the heads off and getting them screw-studded, change the cam/pushrods/lifters back to roller and call it done. Already called machine shop. 100.00 if I supply the studs. One day turnaround. Shouldn't be more than a week of downtime.....haha or three weeks or 2 months.. lol

This will/should keep me going for years to come.

How's about tourque john......Bondo time to step up if you will.

Cam profile's have a huge influence on performance come on guy's it can make as much as 100 hp diff or 75lbs of tourqe


Only problem i see here is inversion....aka how much HP and the risk's involved....

 

[RCSConstruction]

Re: Dead cylinder??

Time for Bondo or Don to chime in here.......

I'm hoping.
You know what though TG? I think those stud girdles will work perfect.
50.00, they screw right on, and group all 8 studs together so no single stud pulls out.

 

[John_S]

Re: Dead cylinder??

"Can anybody confirm whether roller lifters were used in vortec's or not?"

All SBC blocks since 87 were machined to accept roller cams and lifters. Either could be used. In general the roller cam was used in all Mercs starting in '97 production year. This included standard head and vortec head engines. The roller cam was used in Mercs prior to vortec heads being produced. So, in general, production marine vortecs, did use roller cams. There were other changes to the small block around this same time. Crank, rods, pistons, composite valve cover, water pump. Probably more.

When someone advertises a "vortec" engine, the only thing that means is that it has some form of vortec heads. You have to read and ask for details to determine what the rest of the engine is. They sell pre-87 SBC engines as vortecs, too.

As far as the auction goes, that is part of what you need. If you buy those, recommend pollishing the rod ends to prevent possibility of excessive mis-matched part wear. Usually not a problem on rod to lifter and rod to rocker arm, but why risk it.


"What are your thoughts on a stud girdle?"

My thoughts are that something caused it or defect in the rebuild. Shouldn't need to go to that in a stock engine.

Do you have the RV cam specs yet?

 

[John_S]

Re: Dead cylinder??

How's about tourque john......Bondo time to step up if you will.

Cam profile's have a huge influence on performance come on guy's it can make as much as 100 hp diff or 75lbs of tourqe


Only problem i see here is inversion....aka how much HP and the risk's involved....

Merc put the roller and flat based lifters in some of their same year models. HP is the same. They don't advertise the torque curves. I'd bet you couldn't tell the difference.

If you want to spend the money and convert, fine. I am just letting you know that you are not getting much for the $ spent.

There is more of a chance of inversion with the stock marine roller cam.