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TR6 TR6 Roller Rockers

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DougF

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I'm in the ongoing process of sorting out what to do with the motor I am building for the TR6.

I need to purchase new rockers. Mine show wear, so will remain on the current motor. I purchased a new hardened shaft a while ago.

The plan is to build a fast street engine. S2 cam for now(I have one on the shelf), min. 9.5 CR, a good breathing head, triple Strombergs... I am looking at 1.5 lift ratio rockers. I am strongly considering a cold air box.

So the question is, are the roller rockers worth the extra money.
 
DougF said:
So the question is, are the roller rockers worth the extra money.
Click to expand...
For my money, no, not with such a mild cam. The main advantage of roller rockers is that they will handle higher stresses caused by higher rpm operation, radical cams and stiffer valve springs. But they are intended for relatively short-lived race motors and so don't hold up well on the street.

Various sources give different rocker arm ratios for the TR6, but they are all in the 1.45-1.50 range. So a 1.5 arm isn't going to give you much more lift; and an S2 already has plenty of lift for the street and its designed rpm range. If you really do want a little more lift (which will actually hurt low-rpm performance and idle), it would be cheaper to have it ground into the cam (eg TSI's 275 cam with .425" lift and a broader power band than the S2).
 
I toyed with the same thing. I have a mild street cam too with 255 rise, DUR INT 250, EX 254 L/C 108 deg. Along with triple Strombergs too. Don't know if it helped much as far as extra performance but it sure did quited the valve train noise. My concern was to take the pressure off the tappets and the cam. There has been a lot of info out there about poorly remanufactured tappets. Many failures were blamed for them. Tr3driver is correct about getting more bang for the buck in his suggestion. But if you already purchased the S2 cam, Then it's your call. To elevate my concerns I also had the entire engine cryoded. This helps to release the stress in the metals after machining and heat treating.

I like the fact that I get a little piece of mind with the roller rockers. With the cam degreeded and with the pistons ceramic coated, the smoothness of the rollers and when the engine is revving up past 3500 rpm , the motor starts to sound like a Formula 1 motor. I love the sound!!

I must add that $ influenced my decision too. Did some grunt work for a local LBC mechanic and he made me a deal for under $200 for the set. I would not have paid $600.

You may also want to check into the fact I'm starting to hear problems with wear with the roller rockers. Not sure haw many manufactures are out there and probably not a lot. There might be a difference in quality. I did have to adjust the lash once already and may be starting to get some valve noise again. A axillary oil line was installed too.
 
I believe that anytime you can upgrade a component and reduce the friction of a moving part you should. I have the hardened shaft and roller rockers (1.55:1) on a GP2 cam (better). I wish I had purchased the GP roller kit (best). When I was building my motor I now wish I had the cam bearing installed (best). As a matter of fact, there are many things I would have done differently now, getting it done right while you are there.

Now that being said, I know of a SCFI motor out there that produces 190 hp, 200 ft.lbs. at the rear wheels with a stock cam, stock rockers and shaft, and the stock cast iron dual down exhaust manifold. Knowing how you are going to use the motor is the criteria needed in determining the components. Street or race. There are as many opinions from others as there are others.

I suggest you find a motor that is doing what you want to accomplish and improve on that program and setup.

The link in my signiture below takes you to my motor program.
 
By the way, I suggest you consider triple SUs instead of the Strombergs. I am having trouble finding metering needles for tuning the Strombergs. SUs have plenty of available needles.

This is one of those opinions I spoke of in the other post.

Check this with a good carb person.
 
I would not use any new camshaft, unless you enjoy tearing down your engine. Some think the problem is with the people doing the grinding, I don't know. Camshaft/lifter failure can be caused by alot of things. You need to look at the whole package. Camshaft, lifters, springs, collars, motor oil, break in. You need to use exactly the right regrind, and they are hard to find. You won't find many of the right parts in the USA. Be careful, if you want to drive alot, and want it to last. However, it will not have any problems sitting in the garage. I would not do anything that puts more stress on the valvetrain, as it is not a very robust design for high performance, at least not for long term. The original factory PI setups are the best if you want it to last. I think I have the deal figured out, but the parts are hard to come by to say the least.
 
I purchased the cam in the early 90's. I went with the Strombergs because I have them.
It is either the roller rockers or the sending stock rockers out for rebuild. I'd rather have original castings than reproduction.
The plan has been to install cam bearings regardless. Now it is "if needed". I'm expecting the block will need them as it has a minimum 121k miles on it. The speedo was broken and the odometer rolled over at least once.
I'm in no hurry, the machine work is still 4-8 weeks out. The engine in the car is tired but running great and I have no intentions of swapping things out until Spring.
I've been planning this project for many years and am decided on most of the work that will be done.. Things like roller rockers enter and exit the picture. Nice thing is, they can be added at any time.
Thanks for your information.
 
As you have concluded, you can add roller rockers anytime. But if you are spending good money to rebuild the existing rockers, you might want to stay with them. They last a long time when rebuilt properly. I mentioned before in another post that there are big hp motors out there with stock rockers.

Now, it depends on your motor program and the amount required to rebuild the stock rockers. If you are going to have a moderate hp street motor, there is no real need for the rollers. Now if you have money to burn, do the rollers. But remember, no one ever sees them.
 
There is a man in California, I believe, who will reface and bush rockers for a reasonable price. I can't find his website at the moment.
He was recommended by a friend of mine who had him restore the rockers and shaft for his Healey 100.
The man was very aware of TR250/6 rocker shaft woes. If I go that route, there won't be a fortune invested.
I want a dependable motor. Not interested in a grenade.
 
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