timing, cams, valve adjustment

[Rut]

I've got the oil leak under control and the PCV sorted out and my next step is figuring out how to tune the engine. It runs well on jack stands, puffs of smoke on acceleration, but with different modifications such as cam, Weber carb, header, etc. I don't know where to begin. With a Kent cam do I need to know the lift or duration to set the valves or is it pretty standard? I've got the book for tuning Webers, but I think I will eventually go back to the SUs if I can't get a good drivable car. I've got some plumbing to do on the exhaust side since it goes from a 1.75" header to a 2" main to an adapter to a 1.75" Harley muffler. BTW, the oil leak and smoking balancing act was corrected by moving the oil separator hose back to the underside of the air filter and changing the after market aluminum valve cover to an original one with a vent which runs to the port on the intake manifold. I'll either find a ported breather to replace the oil filler cap on the aluminum valve cover or drill it and fit an adapter. Progress is so nice and rewarding and I can't wait until I can go for our first drive!
Rut

 

[BlueMax]

Rut,
If your still have smoke on acceleration or decelaration it would be advise to invest time and money into that issue before you look a the more performance side. How else can you achieve the goal of increasing HP if the engine is not in top operating condition?

Before you choose a camshaft, you need to decide what compression ratio and RPM range that you want your engine tune for, taking in consideration your gear ratio too. Then select a cam that fits those parameters that you choose. The cam company will provide the information to you with all the details the cam needs to optimize its ultimate performance, such as 1.3, 1.5 roller rockers ECT. You may want to speak with David Anton at ATP, but be sure to tell him what you’re looking for and he’ll advise you what will suit you best!

 

[Rut]

BlueMax, thanks for your advice, but my engine is a rebuilt unit with the Kent cam already installed along with the Weber and header. My question is this: do I need to do anything different when adjusting the valves since I have a different cam and do I need to stay with the same timing specs since I have the Weber, cam, and headers. The engine will not be rebuilt for awhile unless I find something wrong with it.
Thanks, Rut

 

[BlueMax]

Rut,
For ultimate performance you need to degree your camshaft to the specifications that your camshaft provider sends with the cam. To achieve the most accuracy you’ll need a degree wheel, dial indicator and magnetic stand to hold the dial indicator in place. For the most accurate results this needs to be done with your head off so as you can find perfect TDC, but doesn’t have to be done that way. Take the specifications that the cam manufactures has provided, then degree it in. The best and simplest way is to have a vernier cam gear to dial in your camshaft, but they do make off set keys to get you close.
I do not know who or how your cam was degreed, only the builder can say. You need the cam specifications to verify that cam’s specification as I have described since there is unanswered questions.

To check if you have an engine that is properly performing. A simple way to do this is with a latex glove. Attach the glove to the oil filler opening on your valve cover holding it in place with a rubber band. Crank your engine up, throttle it hard, if the glove fills up like a balloon you have to much blow by, you have a compression problem!

 

[Rut]

Thanks for the follow up. I'm trying to get the info on the cam that the builder used from the po. As far as crankcase pressure is concerned I'm running a crankcase vacuum since I've drilled and tapped the intake manifold. I used a manometer to help adjust the pressure since a pcv would not do the job This should indicate no or minimal blow by. My main question is valve adjustment...do I use the same valve lash as a stock engine? As far as timing goes, do I need to do something different from normal since I have the current modifications?
Thanks, Rut

 

[BlueMax]

Not knowing how your cam was degreed, if its with in one or two degrees’ of the specified requirments you should be able to run 32-33 degrees @ 4000 RPM with 93 octane fuel with 10- to 1 compression. Valve lash will be provided by cam manufacture on your specific camshaft.

 

[Rut]

Thanks, I think it's the Kent 266 cam (fast road) and I know just enough to be dangerous. I want to make sure that I'm not setting or changing something that will be detrimental to the engine. Aside from being a poor mechanic, this engine is somewhat of a puzzle in that I don't know what's truly been done to it. I have the machine shop work bill, but was told that the engine was built by a very reputable 'restorer'. It runs well (on jack stands) and it only started smoking when I attempted to fix the scroll seal leak by installing a pcv. Before the pcv I had 0 crankcase pressure measured on a manometer. After I added some negative pressure to the crankcase, the leak went away, but I had a little smoke that was not there prior to the pcv so I feel like it's related to that. I will eventually have the engine worked on by someone who knows what they are really doing. I rebuilt several TR3 and 4 engines in my youth with good success. Just standard things like bearings, cylinder liners, pistons, rings, valves, etc. Very straight forward process. Again, thanks for your help and I will find out more as I move along with this process.
Rut