Roller Rocker for a "Mild" Street Stroked 427?

[blykins]

That was a 1.8:1 351C race rocker.   It was the first one I grabbed on the shelf.  Those calipers were the first ones I grabbed as well.   If you want me to measure it with my Brown & Sharpe mics and show you that it's a 1.6" length with greater precision, I can do that too. 

The length can change due to the geometry that's desired and when you start moving dimensions around, you gain/lose, retainer/spring clearance as well. 

Merry Christmas.  Go have fun with your family.  Enjoy the grandkids.

[XR7]

Howie... the 1.60 is the pivot length of the rocker like Brent said, not the ratio. The Blue Thunder for the FE is the same pivot length 1.60. These are "race rockers, and are available in many ratios, with 1.75 being standard, but 1.8 or 1.85 or even up to 2.0 available if desired. The Blue Thunder "THOR" head is a BBF or 385 series head, not FE, and the 1.65  or 1.75 as a custom is again... pivot length not ratio.

T&D make the rockers to order, so you can get any ratio and many offsets if desired, within reason. I have handled a few sets of T&D race rockers for both Blue Thunder and Edelbrocks, have them on my own engine, but never a "street" rocker assembly... so no idea on that stuff, yet. I'll admit the T&D catalog reads a little funny, but you didn't understand it correctly.

[Barry_R]

I personally own a set "and a half" of T&D race rockers for Blue Thunder heads with 1.9 ratio...

[ACHiPo]

Thanks for all the inputs on this.  It seems I've got my answers:  1)  T&D indeed makes really good stuff,  2) the standard T&D aluminum street rockers are not recommended for a daily driver due to fatigue, 3) Any engine builder worth his salt can pick the right combination for my application,

Additionally: 4)  for ~$1800 a set of T&D roller rockers with steel instead of aluminum rockers should work great for my application, or 5) for ~$300 a set of non-adustable steel OEM-style rockers that will also work great for my application. 

Next question:  for my mild application (hydraulic roller with <0.6" lift and running <6200 RPM), does it make sense for additional insurance to add ~$200 for some end stands and another ~$100 for spacers to replace the stock spacer springs?

Merry Christmas!

[turbohunter]

I would say you've pretty much got it right save for one thing.
Your #2 statement is probably (according to the much more experienced guys/builders on the forum) a bit to concrete. You might amend that to say, if you're worried about aluminum fatigue then you might not want to buy these. However as the builders have stated, they are quite confident in the T&D quality. I put much more stock in the experience on the forum as to any interweb research that you (or I) may have done.
As for your question of end stands, everyone here seems to say yes and the smart side of my brain says it certainly can't hurt, only help.
To help solidify this thought for you I'm thinking of a freshen up for my truck engine to include a set of new non adjustables with stands.

[blykins]

I would say the #2 statement is false altogether.  I've got one customer who put 6000 miles on his T&D street rockers just this year alone.  I also have numerous other customers who have extended time on T&D streets.

If you do go with a factory setup, I would use studs and end stands.  Solid spacers are not required and the factory style springs work just fine.  I have numerous setups out there just like that.

[ACHiPo]

I would say you've pretty much got it right save for one thing.
Your #2 statement is probably (according to the much more experienced guys/builders on the forum) a bit to concrete. You might amend that to say, if you're worried about aluminum fatigue then you might not want to buy these. However as the builders have stated, they are quite confident in the T&D quality. I put much more stock in the experience on the forum as to any interweb research that you (or I) may have done.
As for your question of end stands, everyone here seems to say yes and the smart side of my brain says it certainly can't hurt, only help.
To help solidify this thought for you I'm thinking of a freshen up for my truck engine to include a set of new non adjustables with stands.

Turbo,
Thanks.  I based my second statement on an email from T&D that said fatigue can be an issue with aluminum rockers in street applications and his recommendation to use their steel rockers.

Regards,
AC

[ACHiPo]

I would say the #2 statement is false altogether.  I've got one customer who put 6000 miles on his T&D street rockers just this year alone.  I also have numerous other customers who have extended time on T&D streets.

If you do go with a factory setup, I would use studs and end stands.  Solid spacers are not required and the factory style springs work just fine.  I have numerous setups out there just like that.

Brent,
I'll defer to you and the other builders as you have a whole lot more experience than I do--I'm just relaying what the T&D tech wrote to me in an email.

Thanks for the recommendation on the studs and end stands, as well as the education on rockers in general.

Merry Christmas!

AC

[ScotiaFE]

That was a 1.8:1 351C race rocker.   It was the first one I grabbed on the shelf.  Those calipers were the first ones I grabbed as well.   If you want me to measure it with my Brown & Sharpe mics and show you that it's a 1.6" length with greater precision, I can do that too. 

The length can change due to the geometry that's desired and when you start moving dimensions around, you gain/lose, retainer/spring clearance as well. 

Merry Christmas.  Go have fun with your family.  Enjoy the grandkids.

Interesting you do not have the answer.
Didn't think you had one.
Actual setup to measure a rocker sweep.
I run Ersons, they are marked 1.76 on the top. I don't get a full 1.76. And I know my way around a measuring stick.

photo hosting sites

[Barry_R]

Don't have one set up to measure right now.
But I can promise you from many past experiences that T&D is pretty flippin' close to correct.

[blykins]

Howie, we are all proud of you because you put your engine together all by yourself. 

However, insulting me or other forum members because you couldn't understand the terminology in the T&D catalog isn't really the best way to make friends. 

I'm not sure what question I was supposed to have answered, but if you want to ask it again, I'll be more than happy to give you an answer.

[My427stang]

I am at a loss of what the issue is here.

1 - The measurement from center to center on each side of the pivot is the designed rocker ratio and can easily be measured
2 - Depending on how that rocker is designed to get there affects spring clearance (and pushrod clearance too).  In other words, 1.76:1 (or any ratio) can be come about in different arm length combos, within the available space for a given rocker
3 - Functional rocker ratio CAN be slightly different when installed, and can even change throughout travel due to where the rollers, pushrods, valve tips engage, and even how far the adjuster is, or isn't, buried. However, the mechanical ratio of the rocker body is still the same

What would be more interesting than looking at total lift, would be to map out the lobe lift in 5 degree increments, then compare it to what the valve sees.  I bet it'd be very different from a stock foot type rocker to a roller.

[blykins]

Exactly Ross.

Sticking a dial indicator on a rocker arm to try and directly measure rocker arm ratio does absolutely nothing.   What needs to happen is the dial indicator needs to be on the spring retainer and the lift at the valve needs to be compared to the dial indicator measurement directly on the lifter/lobe.   You will lose all kinds of lift to incorrect stand height, pushrod adjuster depth (translates to sweep that doesn't open the valve), pushrod flex, etc.   As a matter of fact, you can raise/lower the rocker stands by .015" increments and see differences in how much the lift at the valve changes. 

It's a given that you're not going to see the exact lift that the cam card dictates.  Engine builders spend a considerable amount of time trying to get the lift at the valve to what it needs to be....whether it's a max lift goal with minimal losses, or to make sure that the lift meets a lift rule. 

[Barry_R]

Not to mention rocker deflection, pushrod deflection, shaft and stand deflection, and even cam deflection on serious race stuff.  On one system I ran I was able to verify .037 total lift loss compared to the system that replaced it.

Any angularity you put into the system will also change rate and angle data points - try adjusting a stock rocker a mile out using one pushrod and then as close as you can using a longer pushrod - - then report back.

[ScotiaFE]

Brent you have it all wrong.
I'm telling you to pound sand.
You don't even talk a good game on the spiderweb let alone run something you own.
You could not cut 0.015" off the bottom of anything.
You don't have the gear.
Put that in your pipe and smoke it.
 

Now as for my picture.
The dial is on the spring and measuring the actual push on the valve. So There.

I build cars laddie.
You're going to have step up your game to get there.

Edit:  The question. "That dimension helps determine what kind of spring you can put underneath it. "  Brent is referring to the 1.60 and 1.65
that I had shown. Please explain to all of those potential customers how you use that number to select the spring they need.