PatriYacht

I bet you found the cause of your engine failure. The valve springs AFR uses for hyd roller cams are good for about .650 lift. If he shimmed them .130 and then he used a cam with .700 lift, it's a wonder the engine would turn over without breaking a rocker or bending a pushrod. The metal from the cam lobes took out everything else. Sorry to hear about your trouble.

PatriYacht

Also, AFR has one of the best intake ports in the industry. If he ground on them, he hurt the flow. I would send them back to AFR or to a good head porter like Jim V to see what can be done to fix them. Once you decide what you're going to do, out this moron so no one else gets taken by him. Good luck.

jeff1000man

I think Isky is the brand. I found some new roller lifters the other day at a dragster shop that had no needle bearings?? They are supposed to be bulet proof. If I build a roller motor in the near future, I will probably give them an experiment.

Never heard of a hard landing from inadequate pressure. What Rpm are you seaking of.

jeff1000man

As the novice in the field, I would agree with that.

PatriYacht

Generally a little too much pressure is better than too little. The jumping and hard landing is usually called valve float and is very damaging to lifters and valvetrain generally. Most hyd roller cams use about 150 seat pressure, 450 open and are good for 5800 rpms. I have freinds that have increased that to 170-180 with no ill effects trying to get 6000 rpm without float. Most small solid rollerslike the ones used in boats or street cars use about 210 seat pressure 600 open and are good for about 7000 rpm before float. The problem with higher pressure is higher heat in the needle bearings in the wheel of the roller and so faster wear. So we're balancing the rpm's we want to run with the amount of wear we're willing to put up with.

jeff1000man

I have heard most of that. I thought valve float was when there was not enough spring pressure to keep the valve lined up inside the guide. Cauing valves to hit as they were passing each other.
What about flat tappet - solid lifter type? You have a preference for those?

PatriYacht

Valves hitting each other is pretty unusual. In most heads the valves are almost parrallel. Maybe in a Hemi. Most times a valve sticks in the guide and a piston hits it. While rollers have a lot of flaws, they seem to be making the most hp and getting about the same reliability. Sorry for the thread hijack.

Mr Gadgets

" I found some new roller lifters the other day at a dragster shop that had no needle bearings?? They are supposed to be bulet proof. If I build a roller motor in the near future, I will probably give them an experiment. "

Were they Joe Schubeck lifters by any chance? I am running Schubeck Roller X lifters. So far they have lived..

This guy that built your motor BadK.. needs to be taught a lesson!! Hate to hear this type of story.. good luck with it..

BillK

Bad,

It sounds like you found the cause in the valve springs. They were probably binding up solid and that is what killed the lifters and the rockers

As far as the stud girdles go, I have only seen one set like that, but I did not think it was even possible to put a set on wrong on a big block because of the valve angles. Of course I have never tried it but I guess a big enough hammer would make it work !

It absolutely amazes me how much of this type of stuff goes on. Especially in this day and age where there is more than enough information available for any decent engine builder to build almost any engine and not have problems. You would not beleive how much of this type of stuff I fix at my shop. It really hurts because it hurts the reputation of all engine builders and machine shops

I am going to repeat what I just said in another post too:

I know a lot of guys will say this is not neccessary but .... what I tell my customers is to run the boat for at least an hour or so very easy. Keep the rpms down, maybe to 3000 or so with a lot of varying rpms. Then change the oil, cut open the filter and look for any problems. Only after you have done that should you go out and hammer it. Unless the engine is broken in on a dyno I personally feel it is best to run it real easy for as long as you can stand it. Just go putt around the river for an hour or so, it will be the best leasure hour you can spend. Then change the oil and filter.

A marine engine is constantly loaded to full power. A good comparison is to hook your trailer up to your truck, find a fairly steep hill that never ends and put your foot to the floor for miles at a time. I dont think any of us would dream of doing that to a brand new truck .... why do it to your new boat engine. The longer you can take it easy on a new engine, the longer it will last.

Just my opinion,

Hope the new engine lasts a long time !!!!

Bill

articfriends

iTrader: (1)

I'm glad you found the problem, its obvious the engine builder was a hack who had no idea what he was doing and made some real glaring errors. When the times is right out this dirtbag like Nordic 95 outed Roccard with his lies and amateurish engine assembly mistakes so he can crawl under a rock and stay there.
Its easy to monday morning quarter back what happened but what I see that would have avoided as much damage as happened would have been a good dyno session,as soon as motor didn't run tight and lash couldn't be maintained it could have been figured out instead of being driven until destroyed. I'm not blaming you in any way don't get me wrong, I'm just saying test running this motor on the dyno should have revealed there was problems,it should have been part of this so called "motor builders" program and if he is ANY kind of a real business man he should step up to the plate and start taking steps towards rectifying this mess he cobbled together although I'm sure you have no intentions of letting him any where near any motor ever again,Smitty