Bradan 365 BB service

Moved to Boxer section.

 

And well recieved by the newest thread voyeur! Great stuff. Love watching these.

 

That's certainly crappy welding..the air pockets.
I was once a welder, not aluminum tho...

I only meant as you examined the OLD valves did you note any cracks or signs of impending doom. Just trying to get a sense of the eternal "how long might they last" question in my own 1976-77 cars.

Stress cracks or material erosion at the assembly welds between the stem and head.

There have been builds trying to reuse the valves that lasted less than a month after all the effort.
Quite right to use some good stainless ones!

 

I’m with Adams, these write-ups are great!

Regarding the valve work, I know quite a few have changed to stainless valves. I wonder if the new solid stainless valves are appreciably heavier than the original hollow stem sodium filled valves, and if so, will the old valves springs will have enough strength to keep the new valves from floating at high revs?
Or are you installing new valve springs as well?

Tex, I've also heard that the old valves just break with no warning signs of impending doom.

John

 

I can already tell the make of those new exh valves just by looking at them. MAKE SURE you place each and every one of those new exhaust valves on a kwik-way or some sort of valve machine to check the run-out/concentricity of the facing. I recently used a set of those same valves and each and every one of them were out .002. This type of concetric issue is caused by the maker placing a face on the valve before the valve has cooled 100% properly. It's a lazy mistake, just make sure you check them first. That goes for any new valve actually.



Also, while it's off why not cut the seats fresh? The stock Ferrari seat cuts are absolutely terrible. Only takes maybe .010 off to do a quick cut and the benefit is good not only for sealing but for flow.

 

Love this thread! I just picked up my 365Boxer in UK few hours ago & spending the next few days with her.

May I know how do you guys repair rusted chassis?

 

Subscribed.

Pete

 

I think you are dead on! Ferrari pilot, I have built quite a few of these heads and I also check every valve for run-out.
It is a must to cut those old seats, the run-out will not be good.
Make sure you vacuum check all valves in the heads to make sure they seat perfectly before assembly.
Also a good idea is to check valve to guide clearance, now is the time to change the guides if you have a problem.
That being said putting new guides in a v12 is a challenge and should only be done by a qualified machine shop.
I do all my seat and guide work on a Sunnen VGS 20, With a carbide pilot It works fantastic.
I have custom made tools to locate the new guides on installation as well as finish ream them concentric with the valve seat, then I cut a multi angle valve seat.
If this is not done, you could be into replacing some valve seats, if not all
and that gets costly.
Great post guys!

 

Guys,

I think we are spelling out the obvious, of course you would cut the seat ... every time a valve is removed and reinstalled the valve to seat mating should be checked if not at the very least lapped. Even lowly GM engine rebuilders would do that, and if you are replacing a valve guide der, yeah the seat WILL have to be recut.

Bradan must be a tolerant person ...
Pete

 

I'm still curious if Bradan or anyone else has any insight to my previous asked question regarding valve work.
I know quite a few have changed to stainless valves. I wonder if the new solid stainless valves are appreciably heavier than the original hollow stem sodium filled valves, and if so, will the old valves springs will have enough strength to keep the new valves from floating at high revs?
Or are you guys doing the work installing new valve springs as well?

I'm curious because I'm considering new exhaust valves when I do the belt service.

thanks,
John

 

There is a small difference in weight, it does not seem to effect RPM or perfeormance.
You should always check valve springs to verify spring pressure at open and closed loads.
Every v12 engine I have built has no problem with rpm, valve float or performance.
So I personaly say there is no issue with the upgrade.

 

I replaced all the valves with SS. Just by feel, they seem to be a little heavier. By how much, I don't know. I also replaced the valves seats, the valve springs and guides.

 

I know this car!
Looks weird in pieces.

 

Thanks!
Much appreciated.
John