koczeka

Hi,

I have a RLZ CNC ported pr3 head, the cam journals are out of line. The machine shop says milling and aling boring is not an option it is so bad.

Is there anybody ever heard of making and inserting bearings into the cam journals? It might by my only option saving the head.

Any useful info is appreciated.

Thanks

DDTECH

I've honestly never heard of that zolton, How out of line are they? I got a guy who's pretty good @ Line honing..
What happened exactly?

koczeka

Do not know the reason, it is the head what had your daemons (I think) braking.
If U put in a cam U can see it is not straight and have scores on some journal. It is at the machine so I can't take pics now. Next week I will bring it to an other shop to have a look.
U know I am located on a different continent.
I am not interested in starting any discussion other then repair options.

DDTECH

Well, first figure out how much out of round it is, from there, you can proceed with a direction.
With new caps and a good machine shop, i dont see it being out of round that much to where it can't be fixed.

angryhillbilly

how would you fit bearings into those journals? how would you get them to stay? what kind would you use? lol
if all else fails, why not try it lol. but i dont see how it could be accomplished.

koczeka

My own questions exactly!
I will post info when talked to the shop.

rich7777

By any chance could you shim the cap's and there mating surface (the head ) and the line hone the journal tunnels to the correct size?

b00stedDC

Yes bearings are available to fix bad cam journals. If they are out of alignment you might be able to just have them align honed.

koczeka

More info on this?

koczeka

FYI guys:
There is a company/guy in my sig. who can do it in the US.
Also, I met an old man here in Hungary who is doing it for 30 years, he is making the inserts (bearings) and the job in house. I will take a few pic when finished.

Uncle Dave

There was a company here in Australia doing alloy spraying for repairs like you are talking about its a common practice in repairing hi cost components that are expensive to replace.

raverx3m

iTrader: (1)

Allmotor. Can you make cams thicker than factory size for bored out cam journals?
If i get them honed and the bore is bigger than oem limit.

koczeka

That would be a good solution, except for linking the cam to the head forever.

raverx3m

iTrader: (1)

well if that head is busted opening the journals would be cheaper than doing bearings etc

and if the cams can be ground bigger to fit the head if you ever get a new head you can resurface the cam surfaces to OEM specs . make them smaller.

koczeka

Agreed.
The repair for me will cost ~$250, that includes all journals modded to accept the bearings.

soxle

did you think inserting ball bearings can make horsepower?

raverx3m

iTrader: (1)

lol where that come from

Rosko

iTrader: (1)

Are you sure it isnt the cam? I assume you have already checked that but its probably just as likely that you may have a warped cam.

I'm sure its possible to machine the head if someone were to make the bearings. Technically they could just be aluminum as well. Sounds like alot of work though unless this is a head thats had alot of work done and really worth saving. You've got to think that if the head is warped, what caused that and what else is messed up? Do the rocker shafts still fit?

I had a head welded a long time ago, the guy got in a hurry and warped it really bad. I contemplated the same thing you are because I had alot of machine work in the head already. The rocker shafts wouldnt even go in it was so twisted. I ended up throwing it away, it just wasnt worth fixing. Even if the cam bores could have been fixed, the geometry still wouldnt be correct with the rocker shaft bore being twisted as well.

Youve also got to be careful with the machine work, if they cut the caps and cut down the head and the cam ends up being lower, the geometry of the cam and rocker may not work... in other words the cam could lose its tangency with the rocker pad and/or slide off the edge if that geometry changes too much.

Rosko

iTrader: (1)

That aluminum head wouldnt last a minute trying to support roller bearings! Would need to ride on hard steel on both sides, and a film of oil should provide less friction than even a roller bearing would especially at high rpm.

koczeka

Rosko, the head I bought was used. The reason for the head status is not clear. Bad surprise...
I have brand new cams, they are straight.
All the caps will be torqued down and the head will be align bored.
The inserts are proper 3 layer bearings and they are machined at the oil feed holes, the head/journal machined to accept the bearing locks. The head retains factory geometry.

soxle

the photo does not show the correct bearing for aluminum, just the idea (I have not found the right photo), but anyway, I looked, there is no place on the head.
koczeka: I think trying to save your head is interesting if there is a lot of work on the cylinder head (valve seat, combustion chamber ...)
I would not weld either here.

Rosko

iTrader: (1)

Except if the rocker arm shaft bores are twisted with the rest of the head. You can straighten out the cam bores, but the shaft bores wouldnt neccesarily run paralell to the cam bores any longer. If the shafts still slide in then it shouldnt be an issue. Its minimal I know but I thought it might be worth mentioning.

I still wouldnt rule out the cams just because they are new. Metal does wierd **** sometimes if there is alot of stress in it. I would hate to see all that work done and still have the same issue, it would be very simple for a shop to fixture the cam between centers and run an indicator on it. Literally would only take 10 minutes.

If you do go through with the work please post pictures and keep us updated, this is very interesting to me at least being a machininst. I love seeing things like this and I wish you the best of luck!

JDM B20 EH2

I have know guys with warped head to get them straightened before haveing them surfaced. If its the whole thing not just the cam lobes look into that. Have you checked to see if the whole head is warp or was it surfaced with out checking or even been surfaced yet?

koczeka

Work is done, I will try to post U a few pics tonight.

soxle

congrats!!