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

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

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.

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

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.

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.

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

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.

Is that set up a single shaft or paired shaft T&D system? If single shaft I've seen the same thing with them
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 '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 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

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.

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.

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.

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

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!

Let me try this again...

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

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.