top of valve height from spring seat

[Nacho-RT74]

what you read, how much height should be the top of the valve from spring seat on BB ? I have found somewhere 1.850" but to bottom of retainer plate... wondering to top of valve.

[Nacho-RT74]

soooooo

[Nacho-RT74]

I can't believe! nobody knows?

[BSB67]

Because the information you are asking for has no real value.  There is no need to know what it is.

What are you really trying to understand?

[don duick]

as long as rocker clears the spring retainer and you have correct preload or valve lash why does it matter? I put a set of crane adjustable rockers on my edelbrock heads and the valve stem was not long enough. The rockers touched the valve springs before the valve stem. I had to shim up the valve stems with a set of lash caps. Sorry I don't remember sizes.

[Challenger340]

My apologies Nacho, I missed this thread completely.

I used to know this dimension off the top of my head ? but I'm getting old I guess..... so I'll have to go look it up.

The dimension "matters" if you are running Heads without an adjustable valvetrain.... and want to maintain a correct amount of Hydraulic Lifter preload.
Of course Head and/or Engine Block milling can also change the Lifter Preload, so a guy should still check.

Stay tuned.

[justcruisin]

Valve seat recession will change the height. Is that what you are considering

[BSB67]

The dimension "matters" if you are running Heads without an adjustable valvetrain.... and want to maintain a correct amount of Hydraulic Lifter preload.
Of course Head and/or Engine Block milling can also change the Lifter Preload, so a guy should still check.

Stay tuned.

Bob, I have to disagree with you that it matters in the context of decisions and actions relative to the valve.  Sure, it will change the preload, but buy itself would not be enough to effect the preload to the point that it matters.  And even if it could, your not going to undo your valve grind(s) or buy different valves.  You'll just get shorter push rods.

If he is worried about geometry, it's too small to matter and there are other changes and variables that need to be accounted for that are more important.

I honestly cannot think of a thing that you would actually do with that piece of information.  

Again, maybe the OP can share why he wants to know.

[Challenger340]

The dimension "matters" if you are running Heads without an adjustable valvetrain.... and want to maintain a correct amount of Hydraulic Lifter preload.
Of course Head and/or Engine Block milling can also change the Lifter Preload, so a guy should still check.

Stay tuned.

Bob, I have to disagree with you that it matters in the context of decisions and actions relative to the valve.  Sure, it will change the preload, but buy itself would not be enough to effect the preload to the point that it matters.  And even if it could, your not going to undo your valve grind(s) or buy different valves.  You'll just get shorter push rods.

If he is worried about geometry, it's too small to matter and there are other changes and variables that need to be accounted for that are more important.

I honestly cannot think of a thing that you would actually do with that piece of information.  

Again, maybe the OP can share why he wants to know.

Yeah you're right... I don't think it should be enough to affect geometry enough to worry about ? unless it got really excessive out of range ?
that said,
I've seen lots of crappy iron head rebuilds with valve tips height variances causing lots of problems using stock stamped rockers.

Everything from someone installed Exhaust seats so high in the chamber(holding the valve tip so low out of the head) that the Lifter had no preload and rattled terribly,(that guy killed his cam anyways because the V/Spring pressure was to the moon as well)
right on down to....
other Valves that sat so far up into the seat in the chamber(because the seats were sunk into the head so far) that the V/tips were then sticking so high out of the Head, that the lifters were basically collapsed like "solids" and actually holding valves open.

I think the Factory spec range for Valve Tip "height" from an unmachined V/Spring Pad on the Head was 1.975" to 2.035" I THINK ?? a .060" range for best Lifter preload.  but again,
I gotta go make sure and check those numbers, because I haven't rebuilt a stock iron head in probably 20 years, and I may be CONFUSED given there was an AMC head spec of 2.075" to 2.135" ? one is Mopar and one is AMC, I forget which is which ? I'll check today.
Nonetheless,
from what I remember they will run anywhere probably another .010" to .015" higher or lower from that range depending on Head/Block surfacing.

[b5blue]

And this info was a primary reason for new Sidewinder heads, to start over with the valve train where it should be.

[BSB67]

Having heads with two crappy valve grinds (i.e. sunk like crazy) is not uncommon, and I'm not aware of any situation where the lifter bottomed out.  Maybe though.  These were stock type deals. Certainly other variables and unknowns in those cases, but if it was a genuine high risk, I think it would have been a common problem. 

I think even low end shops will attempt to "level" the tips after the valve grind.   

And not mentioned earlier, the low cost solution to head cutting/block decking/valve sinking back in the day was tapered rocker shaft shims over the now more common direction of buying new custom length push rods.  Are tapered rocker shims still available?.

[Challenger340]

what you read, how much height should be the top of the valve from spring seat on BB ? I have found somewhere 1.850" but to bottom of retainer plate... wondering to top of valve.

On BB Mopar Heads, the spec for allowable Valve Tip "height" from an un-machined V/Spring Pad is 2.175" to 2.225".
But
we never cared .010" to .020" higher, up to a max of 2.245", because most guys were discarding the stock steel shim head gaskets (.020" thick) in favor of re-installing the Heads with thicker(.040") composition style Head Gaskets, which was raising the entire Head .020", so we could cheat the Valve Tips up to .020" higher which pushed the rocker down again on the other side, closer to the Pushrod for Lifter preload.

hope this helps
Bob @ rmp

[Nacho-RT74]

ok... will read every post later... I have being REALLY busy latelly.

My heads were ported and got installed bigger valves. The "machine shop" what made the valve seats got me the steems at diff height  ( beside the angle job was a shit, set the one on chamber at 0 DEGREES, so flat... IDIOTS ). Some valves are around 0.050 or even more higher than the others. So I'm trying to equilize the seats at the same height, closer to original specs as posible to get everything of this corrected the best as posible. Getting the height from spring seat up to top of valve steem would be the fastest way to get it set I think.

I don't think they will have the micrometer to measure it to spring plate.

[c00nhunterjoe]

Unless you are redoing the heads completly, meaning regrinding and potentially replacing seats, then the height number is still pointless. You will need to simply measure the shortest height and grind the others down to match it. Did you cc the combustion chambers to see how much they vary? Sounds like a real hack did your heads.

[Challenger340]

just my opinion here,
and again I haven't done a set of Iron Heads that I can remember in about 20 years....
nonetheless,
when installing Big Valves like a 2.14/1.81 combo in any of the BB Mopar irons, we would always enlarge/machine cut all our Valve Seats to a uniform height on the chamber side, then do our porting, then when done go back and lap all the valve contacts, then adjust as req'd by hand with stones.
After,
we would then cut the Valve Tips to a uniform height from the V/Spring pads(usually .010" to .015") as long as within that 2.175" to 2.225" range,
then,
machine the V/Spring pad if req'd for bigger V/Springs.

Of course, checking for previous Head Milling can be a P.I.T.A., but on the open chambers as long as the "open" portion of the chamber was between .090" to .110" with a quite deck bridge check we were "good to go".(they always vary chamber to chamber anyways)
but really,
most guys were running adjustable Rockers anyway ?, so unless we knew specifically they were going to re-install a non-adjustable "stamped Steel" Rocker we weren't too concerned.

Nacho are you running "stock" non-adjustable Rocker Arms ?

[b5blue]

  Smith Brothers makes adjustable push rods, a third option from cut to fit or adjustable rockers. I was jacked in the past for referring to this as valve train geometry but it's covered in my Mopar B/RB book that way. With the ratio of rocker valve tip height error's effect is greater at the push rod side. I get why Nacho is trying to sort this all out. It drove me nuts until I just decided for long term planning new heads were in order. I've rocker shaft shims and adjustable push rods, even most of a set of iron adjustable rockers (Used I found a few had been galled up where they ride on the rocker shaft.  ) all bought for cheap to counter valve train issues that new heads will eliminate entirely. 

[BSB67]

  Smith Brothers makes adjustable push rods, a third option from cut to fit or adjustable rockers. I was jacked in the past for referring to this as valve train geometry but it's covered in my Mopar B/RB book that way. With the ratio of rocker valve tip height error's effect is greater at the push rod side. I get why Nacho is trying to sort this all out. It drove me nuts until I just decided for long term planning new heads were in order. I've rocker shaft shims and adjustable push rods, even most of a set of iron adjustable rockers (Used I found a few had been galled up where they ride on the rocker shaft.  ) all bought for cheap to counter valve train issues that new heads will eliminate entirely. 

Couldn't really follow your post.  But generally speaking, the factory head and rockers are pretty close, and you really cannot do much to change that.  It is fine for most stockish applications.   If you've cut a bunch of stuff and sunk the valves, a rocker shaft shim is the simplest and decent fix.   Also, the evidence indicates that the BB Mopar valve train actually has a huge tolerance for poor geometry in mild applications.  My other observation is very few people seem to actually understand valve train geometery.

[b5blue]

In my post I'm relating to Nacho's problem. I've found many times he and I think the same way approaching problem solving. (So I get why he'd like to know what he asked.) Given he's invested heavy in altered heads and thinks he may have a problem, he is trying figure how bad or good it's going to work out before spending more $$.   

[BSB67]

In my post I'm relating to Nacho's problem. I've found many times he and I think the same way approaching problem solving. (So I get why he'd like to know what he asked.) Given he's invested heavy in altered heads and thinks he may have a problem, he is trying figure how bad or good it's going to work out before spending more $$.   

That makes sense. 

[Nacho-RT74]

the problem is I'm ALLWAYS dealing with poor economy, and poor brain and tools mechs which allways mess my stuff. I'm trying to approach the best as posible to stock measurements. Of course I will have to lead every valve to the deeper one, but knowning the stock mesurements, will help on shim the rockers ( I have MRE shim kit ) propperly and adjust the PRW steel rockers I have.

sorry will read post laters ( damn I'm working around 18 hours by day, some days even more )

[Nacho-RT74]

Nacho are you running "stock" non-adjustable Rocker Arms ?

PRW steel adjustable rockers. Which BTW half of them ( the ones in front cilinders ) got seized brass bushings too. Lack of oiling I guess.

[BSB67]

Nacho are you running "stock" non-adjustable Rocker Arms ?

PRW steel adjustable rockers. Which BTW half of them ( the ones in front cilinders ) got seized brass bushings too. Lack of oiling I guess.

Please expand on the details of what happened and your conclusions as to why the failure.   I think a lot of people consider using PRW rockers, and they actually look kinda nice (not that you could see the necessary quality aspects).. I think that would be great info and helpful a lot of folks.

[Nacho-RT74]

Hi guys! old thread resurrection, yes...

Finally got the valve height correctly done at seats. Roughly measured Got between 2.16" and 2.19"... not bad

Now will need to correct the deepness of flat area of 452 chambers... they are all between 0.100" and 0.120"... will try to get them equalized close to 0.125" and cut the heads 0.020" or so.

It seems pistons will leave the deck close to 0.005" IF THEY MAKE A GOOD JOB. This will give me the final decision on the head cut measurement

This should get me a good "quenched" engine using Kb215 pistons and 0.039" headgasket

[Nacho-RT74]

Nacho are you running "stock" non-adjustable Rocker Arms ?

PRW steel adjustable rockers. Which BTW half of them ( the ones in front cilinders ) got seized brass bushings too. Lack of oiling I guess.

Please expand on the details of what happened and your conclusions as to why the failure.   I think a lot of people consider using PRW rockers, and they actually look kinda nice (not that you could see the necessary quality aspects).. I think that would be great info and helpful a lot of folks.

really dunno what really happened. still wondering.

Is a fact I got an lubrication failure because the burnt oil deposits on half front section on valvetrain... even on pushrods!

1,3, 2 and 4 cilinders rockers were the sized ones. 1 and 2 the worst. Rest ones got normal wearing.

Casuality or not, deck height is higher on front... around 0.025 on left, 0.017 on right