Just go along with him, Mike. Life is easier that way. we know that they are short but ------------

---------

By the way DF. the original post was on Small blocks. Mike and I have been answering for small blocks to the OP. You step in and muddy the water with your posts without telling anyone that you are talking BB till after the fact. By the way Mopar valves are 3/8 stemmed unless oversize stems or stelite valve may have a heavier stem. Don't remember for sure and it has been a long time since I have seen either a HD BB with rotators or stelite valves. Probably close to 30 years or more. Like said I have a good memory but slightly shorter than that. You want to change the subject start your own.

M4L .... at choo !

Exh valve rotators ? ....SB ...BB ... whatever !! ....start my own topic ? ... oh THAT should be a hot-topic !!

Justa FYI ... the 413 exh valve has a HUGE stem. Ever hear of a sodium-filled valve ?

How many RV motors have you pulled-down? LOTS of issues on the exh-valve side?

RUIN this thread ? ... I reject that

The OP's question was answered and I simply asked a Q or two and started a little chat that was directly ON TOPIC of an ..

...exhaust valve rotater.

my 360 headed 318 has sodium filled exhast valves and had the rotators on them with a shorter spring than the intake valve did..again SB

after seeing the pic that Don posted of a droped valve,then haveing my 2500$ short block trashed by a droped valve 2nd day on the road...then me finding the tip and locks still in the rotator and 1 spring bouncing around in the VC that was a tall intake spring

and I pointed that out when I droped it at the machine shop too!!!!

I double check them myself from now on..live and learn

So if the tip of the valve stem and the locks were still in the retainer .... how is that the fault of the rotating retainer ?

If one of the springs were shorter(as suggested above) ... would that then possibly kick-out the locks and then drop the valve that way ?

the spring was an intake spring..which is taller

it was compressed to much at the installed hieght,pressure was incressed cause of that

lift was reduced for the retainer and valve guide clearance and made the spring coil bind with the .485 lift

i am sure there was more to it than that but the fact was I found the wrong spring had been installed on it

but the valve guide and seal was chewed up,tip broke off valve,piston shatterd,cyl bore gouged up by piston pin..ect..

dont think a piston hitting a valve will snap the end off of it and leave the locks on the tip in the retainer

the valve that was broke was in the oil pan bent to a 90*

machine shop was good for it and agreed that it was the taller spring snaped the valve tip off then the valve then fell down the hole after the piston shatterd

What IS the height diff ? ... and of course ...as I mentioned above ... coil-bind can be a really bad-deal.

I am going to pop-off one of the intake springs on a 413 head and check me-self.

eyeballing it on the bench it was a good 1/8-1/4 inch..enuff you caold see it with all 16 springs lined up 8 in a row

the one intake spring was not as tall as the other 7 when they were set back on the bench either

still taller than the 8 exhast springs but a tad shorter than the other 7 intake springs afterwords

now the comp 901-16 single with damper fit with stock seals/retainers and have room left over with a .485 lift

this was on a set of the closed chamber swirl port #302 heads also

I used 1.88/1.60 360 valves in them with a home pocket port and bowl clean up

machine shop said the spring load and coil bind was it,took the hit and redid a set of heads,machined a new block up..I had to buy 8 new pistons

never been back there either

SB compaired to a BB is like apples and oranges...no?

I would agree that for the intended use on a stock spec engine they are worth while for longevity

but stock specs are kinda wimpy on cam lift/spring rates

BB to SB springs ? .. they are diff .. but I don't know in what way.

I have the height specs .... 413 IN and EXH ... 2.255 ... 2.110. HP 440 mag ... 2.105.

Here are some specs from the 1984 truck fsm.

318 - 360 w/o rotators took the same spring.
marked with a blue stripe 2 inches tall, .192 wire diameter, 6.4 coils installed height 1 5/8 to 1 11/16

318 w exhaust rotators marked with a white stripe 1.81 inches tall .185 wire diameter, 5.8 coils installed height 1 29/64 to 1 33/64

360 w exhaust rotators marked with a yellow stripe 1.81 inches tall, .192 wire diameter, 5.6 coils, installed height 1 29/64 to 1 33/64

All measured seat to retainer.