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T&D rocker ratio loss when loaded

Posted By: BradH

T&D rocker ratio loss when loaded - 01/16/20 10:22 PM

The T&Ds that I sold recently were advertised as 1.60 ratio, but lost about .05 when installed and measured with both soft checking springs (1.59+) and 600# open springs (1.54+). This isn't the first time I've seen a rocker arm check below the advertised ratio against a "real" spring, but wasn't expecting this with the T&Ds. Has this been other T&D users' experience, too? Thanks - Brad

EDIT: Pic showing they are single shaft and stamped 1.60


Attached picture 20190713_140514.jpg
Posted By: fast68plymouth

Re: T&D rocker ratio loss when loaded - 01/16/20 10:50 PM

I’m sure Andy checked it on the ones he had done for the TF heads.
Posted By: madscientist

Re: T&D rocker ratio loss when loaded - 01/16/20 10:52 PM

They should be the nominal ratio when loaded. They should be higher than the nominal ratio when using checking springs.

I'd send them back.
Posted By: dvw

Re: T&D rocker ratio loss when loaded - 01/16/20 11:08 PM

My paired T&D lose nothing when loaded 800+lbs over the nose..
Doug
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/16/20 11:53 PM

Originally Posted by madscientist
I'd send them back.

As I stated above, I don't own them anymore. The new owner knows what the loaded ratio is and they should suit his application well.

This is more of a "For Informational Purposes Only" question.
Posted By: justinp61

Re: T&D rocker ratio loss when loaded - 01/16/20 11:57 PM

I have 1.7 T&D's on my Indy headed small block. The cam is a Comp solid roller with .433"I/.437"E lobes, with no lash it should be .736/.743". It has .711/.719" at the retainers with.018" lash and the Pac springs. So .007" loss on the intake and .006" on the exhaust, I think it's pretty good considering the horrible push rod angle.
Posted By: INTMD8

Re: T&D rocker ratio loss when loaded - 01/17/20 12:57 AM

Possible they were just packaged wrong and 1.5's or is there a part number on them?
Posted By: AndyF

Re: T&D rocker ratio loss when loaded - 01/17/20 01:03 AM

Originally Posted by fast68plymouth
I’m sure Andy checked it on the ones he had done for the TF heads.


The T&D rocker arms I had made for the Trick Flow heads were supposed to be 1.70 ratio. They ended up being 1.65 ratio. I called and talked to them and they admitted the mistake and offered to build me a new set. I said don't bother and it ended up not making any difference. I dyno tested them back to back against another set of rocker arms that checked out at 1.70 ratio and there was zero power difference.

The T&D rocker arms were the best shaft rockers I've ever run. If I needed another set of high end rockers I'd buy them again in a heart beat. I think the latest version from Hughes is really nice too. The Hughes rockers tend to check lower than advertised so just order one ratio higher than what you need and you'll be happy.
Posted By: Cab_Burge

Re: T&D rocker ratio loss when loaded - 01/17/20 02:27 AM

Is that set up a single shaft or paired shaft T&D system? If single shaft I've seen the same thing with them whiney
The Harland Sharp single shafts are usually a .5 ratio higher than advertised, 1.5 ratio check to be 1.55, 1.60 ratio check to be 1.65 work shruggy'I have one motor now (440-1 heads)that has a set of Jesel paired shafts rockers that are suppose to be 1.55 ratio, I am going to look at my notes and make sure exactly what their true ratio is wrench I'm thinking they where dead on with checking springs, I set them up with 325 lbs. on the seats and 870 Lbs. opened, I'll pull several pairs off and see how they measure now luck
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 05:05 AM

Originally Posted by AndyF
Originally Posted by fast68plymouth
I’m sure Andy checked it on the ones he had done for the TF heads.


The T&D rocker arms I had made for the Trick Flow heads were supposed to be 1.70 ratio. They ended up being 1.65 ratio. I called and talked to them and they admitted the mistake and offered to build me a new set. I said don't bother and it ended up not making any difference. I dyno tested them back to back against another set of rocker arms that checked out at 1.70 ratio and there was zero power difference.

The T&D rocker arms were the best shaft rockers I've ever run. If I needed another set of high end rockers I'd buy them again in a heart beat. I think the latest version from Hughes is really nice too. The Hughes rockers tend to check lower than advertised so just order one ratio higher than what you need and you'll be happy.

Have you checked other T&Ds and found them to be over the stated ratio unloaded and approximately the stated ratio when loaded? I know this is the case with Jesel and Harland Sharp, but can't get a consistent answer for T&D.
Posted By: AndyF

Re: T&D rocker ratio loss when loaded - 01/17/20 05:41 AM

The only other set of T&D rockers that I've checked were fine. As I recall, they were higher with a checking spring and correct with a roller cam spring. But that was just one set. The engine builder I work with uses a lot of T&D rocker arms and I've never heard him complain about them being off. Of course that is Chevy stuff so higher volume production than the Mopar stuff.
Posted By: fbs63

Re: T&D rocker ratio loss when loaded - 01/17/20 11:44 AM

Are they bolted direct to the head? Are you using any kind of "geometry correction" spacers?
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 01:46 PM

Originally Posted by fbs63
Are they bolted direct to the head? Are you using any kind of "geometry correction" spacers?

Assuming you're directing this to me, this setup uses a B3RE spacer setup that pretty much nailed the mid-lift geometry on both the pushrod-to-adjuster and rocker-tip-to-valve-sweep sides. This configuration is consistent with T&D's instructions for setting up the rocker geometry.


Attached picture B3RE TD_1.jpg
Attached picture B3RE TD_2.jpg
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 02:04 PM

Originally Posted by BradH
... This configuration is consistent with T&D's instructions for setting up the rocker geometry.


Attached picture TD geo guidelines.jpg
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 02:26 PM

My last post on this subject for now... I sent T&D an e-mail from their web site with the following question:

Subject: Advertised vs installed rocker ratio

Question: The custom T&D rockers for BB Chrysler Edelbrock Victor heads that I purchased from a vendor last summer are stamped as 1.60 ratio, but measured 1.59+ w/ soft checking springs and 1.54+ w/ 600# open springs with the geometry set correctly for .650". I was expecting (assuming?) the loaded ratio would be approximately the stamped 1.60, not .05 less. I have since sold them, but want to know if I order another set whether I need to specify 1.65 to get an installed & loaded ratio closer to 1.60, or if there was something "wrong" that my first set didn't deliver the advertised ratio.

Thanks,
Brad Haak
Posted By: fbs63

Re: T&D rocker ratio loss when loaded - 01/17/20 03:49 PM

The geometry may be correct in a non running engine but what do you think happens to the whole shaft at 7k? I bet it looks like a worm on the ground.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 04:35 PM

Originally Posted by fbs63
The geometry may be correct in a non running engine but what do you think happens to the whole shaft at 7k? I bet it looks like a worm on the ground.

Not sure how your comment above applies to my post; crankshafts don't stay perfectly straight when they're spinning at high RPM, either, but you still want to know the bearing clearances, etc., when the engine's being assembled.

My point is that the geometry was pretty much nuts on, and not something that should have impacted my ratio measurements.

On the subject of rocker arm geometry (running or not), I'd much rather mine look like what I posted above than what another popular brand of rocker arms look like when you simply bolt 'em down on a set of BB Victors. Holy Sh!t!



Attached picture HS Victor sweep.JPG
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 04:39 PM

Originally Posted by BradH
My last post on this subject for now...

Let me try this again...
Posted By: lancer493

Re: T&D rocker ratio loss when loaded - 01/17/20 04:40 PM

Brad, a while ago I posted about the Victor head/rocker arm ratio subject, using Hughes rockers and B3 correction kit. My results were nearly exactly the same as yours,with light checking springs. I was careful to check for parasitic loss from dial indicator geometry and flexing. My numbers worked out to be 1.43ex and 1.45 in for 1.5advertised rocker ratio.Ordered 2 new 1.6advertised ratio rockers. You guessed it, 1.53ex and 1.55in actual for them. Never measured without B3 kit. My original conversation with Mike at B3 didn't mention a minor lift loss,but in an after the fact conversation I vaguely remember a comment in that direction. Seeing our similar situation and findings points in the direction of the correction kit is probably the root of the problem, as we used two different rocker arm manufacturers, with the same advertised raitos producing nearly identical lift losses. Its like a chess game, every move(0r change ,if you will) counts. Thats hotrodding! Not blaming anyone but myself. I do have a spare set of 1.5's for sale I anybody is interested! Thanks ,Bill
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 04:50 PM

Originally Posted by lancer493
...our similar situation and findings points in the direction of the correction kit is probably the root of the problem...

No, the reason why the Hughes rockers lose ratio with the geometry correction kit is due to the location & angle of the Hughes adjuster screws.

I gave Mike a whole bunch of measurements after doing multiple before & after measurements; Mike worked with someone who does CAD stuff and duplicated my measurements w/in a few thousands of lift. The Hughes rockers are regressive in ratio (start out higher and end up lower); adding the B3RE kit made it more apparent that when the roller-tip geo was changed, it made the pushrod-side issue even more extreme.

This is not the same thing as I'm asking about regarding T&D rockers, which don't have the same issue when the geometry correction is applied.

Here are Mike's CAD drawings, FWIW.


Attached picture CAD Hughes std location.jpg
Attached picture CAD Hughes B3RE location.jpg
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 04:56 PM

More details re the above CAD diagrams for Hughes 1.6 BB rockers measurements taken w/ soft checking spring:

B - Std shaft location "low pivot geo"
- Sweep: 085” & centered
- T&D cup adjuster w/ 9.575" OAL pushrod
- 1st half cam lift (.2136) / valve lift .348 = 1.629
- 2nd half cam lift (.2136) / valve lift .332 = 1.554
- OA ratio = .680 / .4272 = 1.592; ratio change = -.075

D- B3RE shaft relocation for mid-lift geo at net .650"
- Sweep: 045” & slightly inboard of centered
- T&D cup adjuster w/ 9.795" OAL pushrod
- 1st half cam lift (.2136) / valve lift .339 = 1.587
- 2nd half cam lift (.2136) / valve lift .328 = 1.536
- OA ratio = .667 / .4272 = 1.561; ratio change = -.051

Estimated loaded ratio loss at peak lift based on prior measurements w/ 600# open load springs: ~ .05

'A' OA estimated loaded ratio ~ 1.54
'B' OA estimated loaded ratio ~ 1.51

///////////////////////////////////////////////////////////////////////////////

In case anyone reads this the wrong way, I'm NOT "blaming" Hughes for this. Hughes' rockers were made for years by Probe Industries, and this is the same basic design that Probe had before Hughes started selling their rockers. When Probe quit -- or sold off -- its rocker business, I believe Hughes picked up Probe's tooling, etc., and has continued to make them using the same design.

Could Hughes redesign their rockers? Sure, if Dave & Co. thinks it's a problem. I'm guessing he doesn't, so they'll likely stay the same. I've run 'em successfully on a couple of builds, but I didn't understand the nature of their ratio / geometry "quirks" until I did all of my before & after checks w/ the B3RE kit. shruggy
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 04:57 PM

Originally Posted by BradH
Originally Posted by BradH
My last post on this subject for now...

Let me try this again...

I give up.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 05:23 PM

Originally Posted by BradH
No, the reason why the Hughes rockers lose ratio with the geometry correction kit is due to the location & angle of the Hughes adjuster screws.

Pic of T&D 1.45" 1.60 ratio on left; Hughes 1.52" 1.60 ratio on right; difference in pushrod adjuster screw locations & angles very apparent, and all this factors into how the different designs "work" when installed in different configurations w/ respect to the valve & shaft relationships.


Attached picture TD 1.45L x 1.60R_HE 1.52L x 1.60R.jpg
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 05:34 PM

In case Dave Hughes or one of his minions checks out this thread... "Look! I'm running Hughes rocker arms (old style intakes & new style exhausts) on my Victor heads!" laugh2

Seriously, I sold the T&Ds because they didn't get me the ratio increase I was looking for. The net lift between the two brands of "1.6" rockers as set up to run on my heads was virtually identical. scope

Attached picture Hughes 1.6 rockers on Victor.jpg
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/17/20 05:41 PM

How much cam lift were you losing on the 1.55 rockers instead of the advertised 1.6 rockers. And how much ET do you think it was costing you in your street strip car?
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 05:53 PM

Originally Posted by pittsburghracer
How much cam lift were you losing on the 1.55 rockers instead of the advertised 1.6 rockers.

I'll let you reverse-engineer the answer from the following: .650" net lift w/ .018" lash and .433" lobe

Since you may be mathematically challenged, it's right about .020" net lift.

Originally Posted by pittsburghracer
And how much ET do you think it was costing you in your 3800#, 680 HP street/strip car?

Fixed... and I have no idea since my P O S hasn't made it back to the track w/ the new engine build, nor will the engine go back on the dyno before the car is running again. wrench

The other thing was I was expecting to use them in my spare engine build (fresh short block) that might also end up with a different cam. The new cam choice would be influenced by the net ratio vs the lift my valve springs can support, and the lower ratio than expected didn't fit w/ what I'd been considering.

How much do you think it would cost you in your... what did Ray call it... oh, yeah... tin can? tonguue
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/17/20 05:57 PM

Originally Posted by BradH
Originally Posted by BradH
Originally Posted by BradH
My last post on this subject for now...

Let me try this again...

I give up.

hop
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/17/20 05:58 PM

Originally Posted by BradH
Originally Posted by pittsburghracer
How much cam lift were you losing on the 1.55 rockers instead of the advertised 1.6 rockers.

I'll let you reverse-engineer the answer from the following: .650" net lift w/ .018" lash and .433" lobe

Since you may be mathematically challenged, it's right about .020" net lift.

Originally Posted by pittsburghracer
And how much ET do you think it was costing you in your 3800#, 680 HP street/strip car?

Fixed... and I have no idea since my P O S hasn't made it back to the track w/ the new engine build, nor will the engine go back on the dyno before the car is running again. wrench

How much do you think it would cost you in your... what did Ray call it... oh, yeah... tin can? tonguue



Hey don’t blame me because you own a fat car. Lmao 😂.
Posted By: dvw

Re: T&D rocker ratio loss when loaded - 01/18/20 02:47 AM

So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug
Posted By: Cab_Burge

Re: T&D rocker ratio loss when loaded - 01/18/20 03:08 AM

I've seen .001 to .003 gain or loss at the 1/4 mile tracks when tightening up the lash or loosening them up by .006 to .010 shruggy work
I tighten them up until it stops getting quicker and faster up scope
Posted By: mopar dave

Re: T&D rocker ratio loss when loaded - 01/18/20 01:17 PM

I seen the same thing with valve lash loops at the track. Minimal if any on the small block with a solid roller at .700" using a T&D rocker which Pittsburghracer now owns. With a victor head and 1.6 Harland Sharps just bolted on with lash and as the engine would run gave me these patterns. Not perfect, but doesn't look bad and just had the guides checked and giving an outstanding A+ no wear from Sanchez. So their not hurting anything anyway. I haven't done any measuring except for piston to valve clearance.

Attached picture HS 2.jpg
Attached picture 20170204_232635.jpg
Posted By: fbs63

Re: T&D rocker ratio loss when loaded - 01/18/20 02:12 PM

Originally Posted by dvw
So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug

This exactly!

All I'm saying is with the shaft spaced up and over like that there is NO way it stays still. ONLY way I would ever correct geometry would be to mill the stands off and make new ones that TOTALLY surround the shaft. W2's were a good example. I would bet some of your lift loss is from flex in the studs.
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/18/20 03:00 PM

Originally Posted by mopar dave
I seen the same thing with valve lash loops at the track. Minimal if any on the small block with a solid roller at .700" using a T&D rocker which Pittsburghracer now owns. With a victor head and 1.6 Harland Sharps just bolted on with lash and as the engine would run gave me these patterns. Not perfect, but doesn't look bad and just had the guides checked and giving an outstanding A+ no wear from Sanchez. So their not hurting anything anyway. I haven't done any measuring except for piston to valve clearance.






Man now I feel like I was ripped off. You advertised them as 1.6 rockers and now when I put them on this winter and take my Indy rockers off my “tin can” is going to be a DOG. I need a Lawyer. 1-800-slo-ride.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 03:07 PM

I stated above that the T&Ds were never tested on the dyno or the track. The engine was dynoed with the Hughes rockers and I purchased the T&Ds afterwards.

I measured the T&Ds and the Hughes as described above. I have a high level of confidence that my measurements are accurate given the context in which they were taken, from the repeatability of the #s, and the fact that the CAD simulations Mike Beachel ran only varied from my data by .002-.003" max lift.

The response I got from Sheldon at T&D was that they over-ratio their rockers; even my soft spring measurements showed this was not the case for my rockers. There's no geometry issue and no flex issue, it's what they measured.

Cab Burge didn't go into details, but mentioned seeing something similar with a single-shaft system he checked. Andy said T&D made a mistake where his 1.70 rockers measured 1.65 loaded; seems like they have made this mistake more than once. Regardless, there is a lack of consistency somewhere.

I asked my question because I wanted to know if what I found was typical of others' experiences. The answer appears to be "it depends."

You don't like my findings or disagree with my methods? No problem. However, coming up with your own -- rather than simply pi$$ing on mine -- would add more value.


Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 03:15 PM

Dave, your sweep patterns look far more reasonable than the HS Victor pic I posted above. I wonder if there was a fulcrum distance reduction between the first rockers and yours. The ones I measured were even longer than the Hughes' 1.52". If yours are still off the heads, could you check the distance between the shaft pivot centerline and the roller tip centerline?
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 03:27 PM

Originally Posted by pittsburghracer
Hey don’t blame me because you own a fat car. Lmao 😂.

What's the tin can weigh, anyway? I was wondering if we switched engines whose car would pick up and whose would slow down. wink
Posted By: GY3

Re: T&D rocker ratio loss when loaded - 01/18/20 03:31 PM

Originally Posted by dvw
So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug


The Mental Masturbation Nationals! grin

Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/18/20 03:57 PM

Originally Posted by BradH
Originally Posted by pittsburghracer
Hey don’t blame me because you own a fat car. Lmao 😂.

What's the tin can weigh, anyway? I was wondering if we switched engines whose car would pick up and whose would slow down. wink



I’ll just say I’m a racer that races almost every week (7 months a year) at the track for the last 46 years or so. I have never raced a car that weights more than 3200 pounds as I want to go as fast as I can, on a budget, with zero tricks on fancy gadgets. It would be stupid for me to race a FAT car and I never will. If you want to line up, let’s go.
Posted By: fast68plymouth

Re: T&D rocker ratio loss when loaded - 01/18/20 03:59 PM

It’s been a few years since I measured any rockers for ratio correctness.
The last ones were Jesel 1.7’s on Indy 572-13’s....... I don’t remember what the exact numbers were, but the gist of what I saw was there wasn’t any “extra” ratio built in.......and that with 800lbs open load they did lose a little....... but not much.

The farthest off on the high side I’ve measured were some HS 1.6’s on a set of Indy SR’s.
1.67 with checking springs and still about 1.63 with 700lbs spring load.

I’ve tested several BBM rockers that lost over .05 ratio going from checking springs to full spring load.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 04:04 PM

Originally Posted by pittsburghracer
Originally Posted by BradH
Originally Posted by pittsburghracer
Hey don’t blame me because you own a fat car. Lmao 😂.

What's the tin can weigh, anyway? I was wondering if we switched engines whose car would pick up and whose would slow down. wink



I’ll just say I’m a racer that races almost every week (7 months a year) at the track for the last 46 years or so. I have never raced a car that weights more than 3200 pounds as I want to go as fast as I can, on a budget, with zero tricks on fancy gadgets. It would be stupid for me to race a FAT car and I never will. If you want to line up, let’s go.

Are you afraid to admit how light your car is??? laugh2
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 04:12 PM

Originally Posted by GY3

The Mental Mastubation Nationals! grin


Spell Check on Aisle 1, please!
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/18/20 04:15 PM

Originally Posted by BradH
Originally Posted by pittsburghracer
Originally Posted by BradH
Originally Posted by pittsburghracer
Hey don’t blame me because you own a fat car. Lmao 😂.

What's the tin can weigh, anyway? I was wondering if we switched engines whose car would pick up and whose would slow down. wink



I’ll just say I’m a racer that races almost every week (7 months a year) at the track for the last 46 years or so. I have never raced a car that weights more than 3200 pounds as I want to go as fast as I can, on a budget, with zero tricks on fancy gadgets. It would be stupid for me to race a FAT car and I never will. If you want to line up, let’s go.

Are you afraid to admit how light your car is??? laugh2




I’ve mentioned it several times over the years. 2880 with me in it. At one time it was 2550 with my son driving, fiberglass doors, and a few other items I changed out to make it more oldman friendly. If you want to go big block against big block that can be arranged too. Wh me the last time you even ran a car at the track. I hope this build makes it off the dyno alive for you.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/18/20 04:17 PM

This thread has officially derailed... I'm good. wave

P.S. Jeezus, PBR, you are soooooo easy to bait. grin
Posted By: mopar dave

Re: T&D rocker ratio loss when loaded - 01/18/20 04:38 PM

Over all those T&D's I sold you worked pretty good on my pump gas 408 with a half ass tune. 10.38@131 in my 3300# car off a foot brake.
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/18/20 04:42 PM

Originally Posted by BradH
This thread has officially derailed... I'm good. wave

P.S. Jeezus, PBR, you are soooooo easy to bait. grin




Lol. You didn’t bait me. I’ve been shutting guys up for years.
Posted By: mopar dave

Re: T&D rocker ratio loss when loaded - 01/18/20 04:52 PM

Bolted up and valves are lashed. I just need a box of oil and bolt the headers back up and it will be running. Is there a way to measure accurately with the rockers on? I would gladly measure if that's possible as I will be in the garage tomorrow.
Posted By: Cab_Burge

Re: T&D rocker ratio loss when loaded - 01/18/20 05:36 PM

On or off the motor the only way I know of to measure actual valve lift is with a dial indictor on the retainers, that is IF you know the cam lobe lift so you can do the math on the ratios. I use zero lash when checking valve lift, you can do it either way though with or without the lash up
Cam timing at the valve you need the lash your going to use wrench
Don't forget that all the cam timing and valve lift specs are based on the lobe , not at the valve retainers except for the gross lift shruggy
Posted By: GY3

Re: T&D rocker ratio loss when loaded - 01/18/20 05:45 PM

Originally Posted by BradH
Originally Posted by GY3

The Mental Mastubation Nationals! grin


Spell Check on Aisle 1, please!


They say you go blind from it, so that's my excuse!

Fiksed.
Posted By: madscientist

Re: T&D rocker ratio loss when loaded - 01/18/20 05:54 PM

Originally Posted by fbs63
Originally Posted by dvw
So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug

This exactly!

All I'm saying is with the shaft spaced up and over like that there is NO way it stays still. ONLY way I would ever correct geometry would be to mill the stands off and make new ones that TOTALLY surround the shaft. W2's were a good example. I would bet some of your lift loss is from flex in the studs.



So it's ok to make a rocker with a said 1.6 ratio but it's not 1.6? That's what i call JUNK. As Brad posted above even T&D will tell you ALL rockers FLEX. Every. Single. Brand. Always.

Of the rocker is designed correctly, that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.

T&D screwed up. That's just a simple fact.

The other simple fact is what happens under load now? The rocker was already down on ratio, and now you load it and put some RPM to it. You lose even more ratio.

Why settle for something made incorrectly? Chrysler people just awe me with what they tolerate from the aftermarket.
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/18/20 06:07 PM

Originally Posted by madscientist
Originally Posted by fbs63
Originally Posted by dvw
So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug

This exactly!

All I'm saying is with the shaft spaced up and over like that there is NO way it stays still. ONLY way I would ever correct geometry would be to mill the stands off and make new ones that TOTALLY surround the shaft. W2's were a good example. I would bet some of your lift loss is from flex in the studs.



So it's ok to make a rocker with a said 1.6 ratio but it's not 1.6? That's what i call JUNK. As Brad posted above even T&D will tell you ALL rockers FLEX. Every. Single. Brand. Always.

Of the rocker is designed correctly, that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.

T&D screwed up. That's just a simple fact.

The other simple fact is what happens under load now? The rocker was already down on ratio, and now you load it and put some RPM to it. You lose even more ratio.

Why settle for something made incorrectly? Chrysler people just awe me with what they tolerate from the aftermarket.




Most of us are street n strip or bracket guys. I worry more about durability than I do about a well made product costing me .020 cam lift. I could Dick around with an engine forever making it perfect on the engine stand but I would rather be out having fun at the track. I’ll pick up more being on the track tuning than I lost from cam lift.
Posted By: fast68plymouth

Re: T&D rocker ratio loss when loaded - 01/18/20 06:11 PM

Quote
that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.


At what load does the rocker go from too much ratio to the “correct” ratio?
Posted By: madscientist

Re: T&D rocker ratio loss when loaded - 01/19/20 01:21 AM

Originally Posted by fast68plymouth
Quote
that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.


At what load does the rocker go from too much ratio to the “correct” ratio?



You'd be surprised. It does take much. And, once you load the rocker I doesn't change worth more load up to the point of failure.
Posted By: madscientist

Re: T&D rocker ratio loss when loaded - 01/19/20 01:24 AM

Originally Posted by pittsburghracer
Originally Posted by madscientist
Originally Posted by fbs63
Originally Posted by dvw
So after all of this measuring , losing, gaining lift I ask. What was the difference at the track? Or was it never track tested?
Doug

This exactly!

All I'm saying is with the shaft spaced up and over like that there is NO way it stays still. ONLY way I would ever correct geometry would be to mill the stands off and make new ones that TOTALLY surround the shaft. W2's were a good example. I would bet some of your lift loss is from flex in the studs.



So it's ok to make a rocker with a said 1.6 ratio but it's not 1.6? That's what i call JUNK. As Brad posted above even T&D will tell you ALL rockers FLEX. Every. Single. Brand. Always.

Of the rocker is designed correctly, that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.

T&D screwed up. That's just a simple fact.

The other simple fact is what happens under load now? The rocker was already down on ratio, and now you load it and put some RPM to it. You lose even more ratio.

Why settle for something made incorrectly? Chrysler people just awe me with what they tolerate from the aftermarket.




Most of us are street n strip or bracket guys. I worry more about durability than I do about a well made product costing me .020 cam lift. I could Dick around with an engine forever making it perfect on the engine stand but I would rather be out having fun at the track. I’ll pick up more being on the track tuning than I lost from cam lift.





I agree 100%. That doesn't change the fact the rocker wasn't built correctly. I have no doubt the rocker would have functioned. I want what I pay for. If ou follow that line of thinking, the rocker could measure 1.55 ratio, or less and been ok.

At what point do you send the junk back?
Posted By: mopar dave

Re: T&D rocker ratio loss when loaded - 01/19/20 09:26 PM

Brad, I set up an indicator on the retainers today and took some measures on valve travel. My cam lobes measure .403/.410 and I use a 1.6/1.5 HS rocker. Intake measured .630 open and the exhaust measured .600 open. Cold lash was set to .015/.015", so looks like my rockers are true 1.6/1.5 ratios under pressure. I only cycled each valve one time, no double checking measures like I usually do, but I think this is accurate.
Posted By: HardcoreB

Re: T&D rocker ratio loss when loaded - 01/19/20 11:08 PM

Originally Posted by madscientist
Originally Posted by fast68plymouth
Quote
that rocker will be over the nominal ratio so that under LOAD the rocker will have the nominal ratio.


At what load does the rocker go from too much ratio to the “correct” ratio?



You'd be surprised. It does take much. And, once you load the rocker I doesn't change worth more load up to the point of failure.


This is consistent with my findings....I assumed a typo and you meant DOESN'T take much. I don't remember the exact number but it was around 400lbs to full system deflection which was about .027" loss. (difference between checking spring and real spring on a TD shaft system 7/16'' pushrods) typically the TD that I have checked were as described by design with about .02 'extra' ratio. However the shaft system I am speaking of above is LABELED/STAMPED 1.5 and it measures nearer 1.6 unloaded. Because of the placement angle of the adjuster running the longest pushrod possible increases the ratio slightly as well. The paired-rocker system deflection was about the same amount of lift loss as well.
Posted By: BradH

Re: T&D rocker ratio loss when loaded - 01/20/20 02:17 PM

Quote
At what point do you send the junk back?

Just to be clear, they were (are) not "junk". The ratio measurements were the only thing I was looking to validate.
Posted By: madscientist

Re: T&D rocker ratio loss when loaded - 01/20/20 04:34 PM

Originally Posted by BradH
Quote
At what point do you send the junk back?

Just to be clear, they were (are) not "junk". The ratio measurements were the only thing I was looking to validate.



I get that. Again, my question is how far off can the be before they are junk and you send them back? I have a set of Chinese rockers. They are 1.6 ratio. I forget what they are unloaded, but loaded, they are exactly 1.6.

If PRW can hit the mark, I'd expect companies with a much higher price point to beat least as good.

To me, that is junk. It's nice T&D offered to take them back. They were not correct. They were made defective. That means junk to me.
Posted By: pittsburghracer

Re: T&D rocker ratio loss when loaded - 01/20/20 05:16 PM

Originally Posted by madscientist
Originally Posted by BradH
Quote
At what point do you send the junk back?

Just to be clear, they were (are) not "junk". The ratio measurements were the only thing I was looking to validate.



I get that. Again, my question is how far off can the be before they are junk and you send them back? I have a set of Chinese rockers. They are 1.6 ratio. I forget what they are unloaded, but loaded, they are exactly 1.6.

If PRW can hit the mark, I'd expect companies with a much higher price point to beat least as good.

To me, that is junk. It's nice T&D offered to take them back. They were not correct. They were made defective. That means junk to me.



For all we know was the rocker ratio off, or the guy checking it??? Was it set at zero lash exactly or was there a fudge factor. Hmmmm
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