RHS head valve train geometry issue

[yellow rose]

I'm just kinda shocked to read all this. Mine are Indy/Rhs, 2010 Era and have run a .556 flat tappet all the way to a .681/.688 Solid roller and my geometry is about as good as a guy could want. Same Hughes 1.6 rockers....again 2010 era.

No shims, lash caps, just never had a problem. Did I just get lucky or is the newer ones the problem?

If you think of all the things that go into geometry, you could get lucky. But more than 99% of the time, you won't. And the only way to fix it is either offset stands and shafts or the Mike's way. You can't increase lift, change the rocker arm and move the installed height and not expect the geometry to be right.

With all the different rockers out there, and they all have different roller diameters, all those factor in too.

And then guys are told to use a lash cap.

You just cringe but the mouths that roar go off and finally you just give up. The shaft must go up and AWAY from the valve as the lit goes up, or installed height gets longer etc.

 

[Cudafever]

"Causing other problem" is pretty vague. I'd be curious to know what the specifics were.

I would have to argue that the geometry needs to be correct no matter what rpm the engine is running. I have had a valvetrain start to become unglued as low as 4000 rpm when the geometry wasn't right. Corrected, the same motor spun freely to 6000, and peak power was at 5200. Mild engines need proper geometry too.

I don't understand why the valvetrain isn't important until the motor sees 7000+ rpm. Drop a valve at 5000 and you will be replacing a lot more than just a valve.

Just inexperienced saying dumb stuff i guess, but relating the valve train to piston speed/ rpm. stock part, low rpm, live for ever. high rev short life without lighter parts and a much more precise balancing job.

If i still had the pic's i would post them up here but they died along with my last computer:violent2:

The sweep of the roller was vary small. but off center of the valve. I wish i could have read your article while i was building my motor.
If i have to pull it down for any reason, will be re reading them article and see where it is at.

 

[Rat Patrol]

Dont know Ironmike...but I believe this is why Indy sold the manufacturing rights to Comp.

Mike - I dig what you're saying about 'up and away' - the offset aspect was what I wanted to hear you say in your first post...I knew it wasnt a simple fix.

Great article BTW!

 

[fishy68]

I'm just kinda shocked to read all this. Mine are Indy/Rhs, 2010 Era and have run a .556 flat tappet all the way to a .681/.688 Solid roller and my geometry is about as good as a guy could want. Same Hughes 1.6 rockers....again 2010 era.

No shims, lash caps, just never had a problem. Did I just get lucky or is the newer ones the problem?

Sometimes you just get lucky Mike. I have EQ heads with Harland Sharp rockers and the geometry is spot on with them. The total sweep pattern at .550" valve lift was less than .025"

 

[Cudafever]

What did Brian say about potential valve guide wear?

He felt it was a non issue.
compared to them pics. Mine were on center! WOW

With the smaller valve stem, a little off center seamed like a lot.
Once i got that in my head, i quit bugging him about it. the scrub rate or walk on the valve was vary small. around .030. didn't get nowhere near the edge of the stem like them pics.

With the shims.......if i remember right, there was more walk, but more center at 0 lift......I think. I just remember that he thought valve stem/guides were not going to be a problem and he didn't like the shim idea. one of the reason was the fact that i was stacking shim, and the potential of oil leaks because of it.

 

[Cudafever]

found some on my work computer. these are without shims

yeah a little off on my .030" guess
real don't have any complaint, it runs Great

 

[Cudafever]

Ok because of that big RED x above, i will make a few more opinions on this Old thread.
First off,.077" sweep is a lot, and yes i know that i'm losing lift because of it.
Brian said that i was better off without the shims. I trusted his opinion that it would be fine,Not perfect but fine.
Been beating on this stroker for over 2 year and have had 0 issues. as i have stated before, it only turns 5800 rpm. However, i mostly race at 1/8 mile tracks. when i took it to a 1/4 track i had to push it out the back at 6800 rpm. No issue, and that's with a Heavy Hyd roller lifter!

I have learned a lot about Valve Train Geometry sence then.
Even though i have had no problems, if i was to buy another cam or do something with the heads i would buy B3 geometry kit to fix these head and get all i can out of them.

I will re add a few more links for help with someone doing a search and finding this thread

Here is the geometry kit
B3 Racing Engines LLC - Performance Engine Building and Mopar Valvetrains

And here is the article that explains why it is so important to have good valve geometry. And this is the best explanation on the subject that i have found. Not a bunch of number and equations just some down to earth but full explanation of the subject. If you want to know a little bit or alot more on the subject.......It's only a click a way.
B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech

I'm still waiting on article #5 Mr Beachel!

 

[yellow rose]

Ok because of that big RED x above, i will make a few more opinions on this Old thread.
First off,.077" sweep is a lot, and yes i know that i'm losing lift because of it.
Brian said that i was better off without the shims. I trusted his opinion that it would be fine,Not perfect but fine.
Been beating on this stroker for over 2 year and have had 0 issues. as i have stated before, it only turns 5800 rpm. However, i mostly race at 1/8 mile tracks. when i took it to a 1/4 track i had to push it out the back at 6800 rpm. No issue, and that's with a Heavy Hyd roller lifter!

I have learned a lot about Valve Train Geometry sence then.
Even though i have had no problems, if i was to buy another cam or do something with the heads i would buy B3 geometry kit to fix these head and get all i can out of them.

I will re add a few more links for help with someone doing a search and finding this thread

Here is the geometry kit
B3 Racing Engines LLC - Performance Engine Building and Mopar Valvetrains

And here is the article that explains why it is so important to have good valve geometry. And this is the best explanation on the subject that i have found. Not a bunch of number and equations just some down to earth but full explanation of the subject. If you want to know a little bit or alot more on the subject.......It's only a click a way.
B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech

I'm still waiting on article #5 Mr Beachel!

I'm waiting too.

I know he busy so im PATIENTLY waiting for the next installment.

Ding ding ding ding ding ding ding........that's supposed to be the theme song from Jepardy but I think I botched it.

 

[B3RE]

Ok because of that big RED x above, i will make a few more opinions on this Old thread.
First off,.077" sweep is a lot, and yes i know that i'm losing lift because of it.
Brian said that i was better off without the shims. I trusted his opinion that it would be fine,Not perfect but fine.
Been beating on this stroker for over 2 year and have had 0 issues. as i have stated before, it only turns 5800 rpm. However, i mostly race at 1/8 mile tracks. when i took it to a 1/4 track i had to push it out the back at 6800 rpm. No issue, and that's with a Heavy Hyd roller lifter!

I have learned a lot about Valve Train Geometry sence then.
Even though i have had no problems, if i was to buy another cam or do something with the heads i would buy B3 geometry kit to fix these head and get all i can out of them.

I will re add a few more links for help with someone doing a search and finding this thread

Here is the geometry kit
B3 Racing Engines LLC - Performance Engine Building and Mopar Valvetrains

And here is the article that explains why it is so important to have good valve geometry. And this is the best explanation on the subject that i have found. Not a bunch of number and equations just some down to earth but full explanation of the subject. If you want to know a little bit or alot more on the subject.......It's only a click a way.
B3 Racing Engines LLC - Mopar Rocker Arm Geometry Tech

I'm still waiting on article #5 Mr Beachel!

Oh you are, huh?
Well, I have been busy! That's why my postings here have been sporadic at best. I just dynoed a small block on Friday, that took a lot of my time and profited very little, if at all. The customer wanted to buy all of his own parts, and then got pissy when I charged him all the labor to fix up his cheap parts. If I keep getting builds like that, I definitely won't have time for the next tech write-up, or finish my web store, or post more on FABO, or or or......Sorry, I'm complaining again. I'll try to make some time here after the season rush calms down a bit.

By the way, you mentioned losing some lift, but that's not so much what I worry about. I'm worried about the lost area under the curve from the valve coming off the seat too slowly, and dwelling less time at higher lifts where the heads are actually moving air. I would rather lose .020" max lift, than a pile of area throughout the full lift cycle. Just how much difference is there in flow from that .020" anyway (especially if it doesn't stay there very long), considering what is lost elsewhere?
Its something I'm betting most don't think about.

 

[B3RE]

I'm waiting too.

I know he busy so im PATIENTLY waiting for the next installment.

Ding ding ding ding ding ding ding........that's supposed to be the theme song from Jepardy but I think I botched it.

Doo dee doo doo, doo dee doo doo, doo dee doo doo doo doo doo.

How's that?

 

[Cudafever]

B3RE Wrote:
By the way, you mentioned losing some lift, but that's not so much what I worry about. I'm worried about the lost area under the curve from the valve coming off the seat too slowly, and dwelling less time at higher lifts where the heads are actually moving air. I would rather lose .020" max lift, than a pile of area throughout the full lift cycle. Just how much difference is there in flow from that .020" anyway (especially if it doesn't stay there very long), considering what is lost elsewhere?
Its something I'm betting most don't think about.

Yup and before your articles, "Geometry" was the rocker arm had to be on center(not necessarily true) and that the smaller the sweep the better.
I had a cam, custom built for my motor combo, and the altitude that i live at. I really don't think that if i had another cam built that it would gain much in torque or hp in the rpm range that it lives at. I really think that getting your kit, and setting it up like it's supposed to, might net me more HP/trq then a cam swap could.

The main reason, ok 2 reason why i haven't pulled the lever on them is.
#1 Will have to buy another set of custom push rods
#2 My favorite saying......If it's not broken, don't fix it.
I assure you, we will have a phone conversation on this kit, but, not until i'm ready to pull the trigger.
I'm really thinking that this will be next winter's project. and will be a nice apple to apple comparison.

 

[B3RE]

B3RE Wrote:
By the way, you mentioned losing some lift, but that's not so much what I worry about. I'm worried about the lost area under the curve from the valve coming off the seat too slowly, and dwelling less time at higher lifts where the heads are actually moving air. I would rather lose .020" max lift, than a pile of area throughout the full lift cycle. Just how much difference is there in flow from that .020" anyway (especially if it doesn't stay there very long), considering what is lost elsewhere?
Its something I'm betting most don't think about.

Yup and before your articles, "Geometry" was the rocker arm had to be on center(not necessarily true) and that the smaller the sweep the better.
I had a cam, custom built for my motor combo, and the altitude that i live at. I really don't think that if i had another cam built that it would gain much in torque or hp in the rpm range that it lives at. I really think that getting your kit, and setting it up like it's supposed to, might net me more HP/trq then a cam swap could.

The main reason, ok 2 reason why i haven't pulled the lever on them is.
#1 Will have to buy another set of custom push rods
#2 My favorite saying......If it's not broken, don't fix it.
I assure you, we will have a phone conversation on this kit, but, not until i'm ready to pull the trigger.
I'm really thinking that this will be next winter's project. and will be a nice apple to apple comparison.

Yes, you would need new longer pushrods. How much longer would depend on how much correction is needed.

I never guarantee that there will be an increase in performance. I'll let that to the salesmen who say anything to sell a part. There are just too many variables to make a guarantee, other than it will be as right as possible for the combination of parts. That I can control. That being said, there should always be some benefit, whether realized or not. For instance, when the valvetrain is stable, the motor will need less valve spring. But, if someone has too much already, they aren't likely to change them, and the motor may not see an increase in rpm. This has been the most common approach for instability. Throw more spring at it. FWIW, I have had customers do a back to back test on this and dropped a substantial amount of spring pressure.

I'm glad you rechecked the sweep on your motor, and found it was more than the .030" you previously thought. Whenever someone tells me they have that narrow of a pattern, and they haven't relocated the shafts, I won't tell them they are wrong, but in the back of my mind I know it's not possible. The math simply doesn't work. Most small blocks with a typical aluminum roller rocker, and stockish length valves, will have anywhere from .070"-.100" sweep before the rocker reverses sweep direction.

This week I will be putting the top end together on a 8000 rpm BBM with a set of my custom T&D rockers. I'll snap a couple pics and post them to the big block forum. With a .708" net lift, both the valve and pushrod sweep is miniscule.

Gotta get back to "Family Time" now!

 

[mullinax95]

Watching and learning. I have recently installed a new set of CNC Eddy heads, 234 @.50/.534 lift roller cam, and Air gap intake on my little .30 over 360. Using adjustable roller rockers that I don't even recall who makes them or where I got them. Bought them like 10 yrs ago. They look pretty heavy duty and don't have needle bearings but.... The roller footprint on the valve tip isn't perfectly centered... more to the exhaust side. Watching and learning in order to correct this.