which roller rocker ratio?

[84BuickGNYorkPA]

I'm currently on back order for 1:55 roller rockers, but I believe the 1:60 are in stock. This is for the new build in my signature, should I look for 1:55 or would I be happy with the 1:60. Figure on Champion Iron Heads for these roller rockers.

Thanks,

Chuck

 

[Just a Six??]

I have no issues with my 1.60's & I run a 210-215 cam so I dont see any big issues? Altho, I'm not an expert on the subject.

 

[84BuickGNYorkPA]

Thanks, glad to hear that you are running the 1:60 with no problems. I just got a email from the vendor, no rockers in stock. 4-6 wks untill they come in, production problem.....

Chuck

 

[Nick McCardle]

Thanks, glad to hear that you are running the 1:60 with no problems. I just got a email from the vendor, no rockers in stock. 4-6 wks untill they come in, production problem.....

Chuck

SE Turbo has T&D 1.55s, just talked to them and ordered some- said their supplier has them in stock.

 

[84BuickGNYorkPA]

SE Turbo has T&D 1.55s, just talked to them and ordered some- said their supplier has them in stock.

Thanks, $45 more then FT, but T&D instead of Harland Sharp. Both seem to be a good product after doing a search.

Edit: Shooooooooot they are out of stk also, was told one week wait.

Chuck

 

[84BuickGNYorkPA]

I found a new T&D 1.65, again not sure if this is what I want for the street, with some track time......... for my spare motor.
Any comments on the 1.65 for a street motor...

Chuck

 

[ijames]

Chuck, I've never heard of any reliability issues with the T&D's with any ratio. Just make sure the springs and retainer/seal/guides can handle the lift, and check the valve-piston clearance.

 

[bison]

I'm currently on back order for 1:55 roller rockers, but I believe the 1:60 are in stock. This is for the new build in my signature, should I look for 1:55 or would I be happy with the 1:60. Figure on Champion Iron Heads for these roller rockers.

Thanks,

Chuck

What is you lobe lift, spring installed height, and coil bind height?

 

[84BuickGNYorkPA]

Carl,
What I meant was will this go ok with this cam for the street... because this will raise the valve opening more. And giving it the characteristics of a cam with a different grind.


Bison,

This is Mike's cam kit at Fullthrottlespeed 210/215
Intake 210 @ .050 .516 lift
Exhaust 215 @ .050 .516 lift
110 L/S (installs at 110)
(lift with stock rockers)

(lift with stock rockers) = 1.55
.516 (lift) / 1.55 (stk ratio) = .332 lobe lift
.332 X 1.65= .5478
.5478 - .516 = .0318 more lift

The springs I will need to dig a little deeper the website says " "BEEHIVE" SPRINGS FOR BUICK ROLLER CAMS"

This is from car craft "Math Anyone?
If you're not sure what the valve-lift numbers will be with a larger-ratio roller rocker, then get out the calculator as we fill you in. Take the intake/exhaust lift numbers from the cam catalog and choose one side to begin with. For example, the Comp Xtreme Energy 268H has 0.477-inch lift at the valve on the intake side. Since the 350 comes with a factory 1.5:1 ratio rocker arm, we take 0.477 and divide it by 1.5. This results in 0.318 inch, which is our lobe lift on the intake side. Next, take 0.318 and multiply it by the new arm ratio. With a 1.6:1 rocker, this gives us 0.508-inch valve lift at max lift, an increase of 0.031 inch. It doesn't sound like much, yet it was enough to show a sizeable gain, mainly because it increases the amount of time that the valves are open at higher lifts, allowing more air to flow through the heads. The valve will now see 0.500-inch lift twice during each combustion cycle (once as it opens and again after peak lift on the closing side)"

Chuck

 

[bison]

Carl,
What I meant was will this go ok with this cam for the street... because this will raise the valve opening more. And giving it the characteristics of a cam with a different grind.


Bison,

This is Mike's cam kit at Fullthrottlespeed 210/215
Intake 210 @ .050 .516 lift
Exhaust 215 @ .050 .516 lift
110 L/S (installs at 110)
(lift with stock rockers)

(lift with stock rockers) = 1.55 So .516(lift)/1.55(stk ratio)=.332 actual valve lift
.332 X 1.65= .5478 lift with a 1.65 ratio rocker

The springs I will need to dig a little deeper the website says " "BEEHIVE" SPRINGS FOR BUICK ROLLER CAMS"

This is from car craft "Math Anyone?
If you're not sure what the valve-lift numbers will be with a larger-ratio roller rocker, then get out the calculator as we fill you in. Take the intake/exhaust lift numbers from the cam catalog and choose one side to begin with. For example, the Comp Xtreme Energy 268H has 0.477-inch lift at the valve on the intake side. Since the 350 comes with a factory 1.5:1 ratio rocker arm, we take 0.477 and divide it by 1.5. This results in 0.318 inch, which is our lobe lift on the intake side. Next, take 0.318 and multiply it by the new arm ratio. With a 1.6:1 rocker, this gives us 0.508-inch valve lift at max lift, an increase of 0.031 inch. It doesn't sound like much, yet it was enough to show a sizeable gain, mainly because it increases the amount of time that the valves are open at higher lifts, allowing more air to flow through the heads. The valve will now see 0.500-inch lift twice during each combustion cycle (once as it opens and again after peak lift on the closing side)"

Chuck

That is a little steep for most springs. Id check for coil bind. Increasing the rocker ratio will increase the duration slightly. It will also increase the overlap slightly

 

[84BuickGNYorkPA]

Bison,

I just seen in your signature this is what you are running, 8445 heads with 1.65 rockers, what kind of driving do you do? Street and track or just track?

Chuck

 

[bison]

Bison,

I just seen in your signature this is what you are running, 8445 heads with 1.65 rockers, what kind of driving do you do? Street and track or just track?

Chuck

That was 99% street. My total lift at the valve is only .497 with the 1.65 rockers and the 212. I ordered a grind with less lift because i wanted to run the 1.65 rockers i already had on hand and didnt want to be on the edge with the springs. I use comp 941 springs and i shift at 5900 . Lift would have been around .530 with the other grind. Imo with most of the ported iron heads out there going over .500 lift does little for performance. The head flow really slows down a lot over .500 lift.

 

[84BuickGNYorkPA]

I talked to Ken (Turbofabrictor) on the phone and he told me to go for the 1.65, that's what he would have recomended I get. And the other day I talked to Sod (Hyetech) and right away he said about the 1.65.
So I just bought a new set of TA Performance T&D 1.65's
Thanks for everyone's help,

Chuck