TR6 TR6 performance help

[ichthos]

I need some help on another car, my recently rebuilt TR6. The rebuild also included my carbs, which were supposedly totally rebuilt (I am not sure of the quality of the rebuild since one one of the floats had a pin hole in it they hadn't caught.) Even though my engine was shot before my total rebuild, it was a great racer through mountainous terrain. I could punch it, and could accelerate quickly up a steep incline. Now that my engine is broken in and I am pushing it a little, I no longer have the quick acceleration I once did. Any thoughts on what I need to adjust? I thought I was very thorough in my adjustments in September. Does this sound like valve adjustment, timing, carbs, or vacuum leak? I forgot to mention that the idle seems to be inconsistent at times.Any suggestions are appreciated.
Kevin,

 

[DougF]

Any othe symptoms such as noises, backfiring, popping? A quick check of the vacuum connectors for deterioration will give an idea if you have leaks.

 

[ichthos]

Nothing is consistent, which is what baffles me. I occasionally the idle will drop when I stop quickly to the point where it almost dies. It seems starved for power when I accelerate on an incline. i had replaces all of the vacuum connectors about 5 years ago. I did not replace them when I rebuilt the engine. They already look a little worn, but I had a heck of a time the last time finding a vendor that had connectors that fit well. Any idea which of the major three has some that fit correctly?
Kevin

 

[big6]

Check your distributor to see that at TDC #1 cylinder on compression stroke the distributor rotor is pointing to the correct distributor cap tower for the #1 cylinder. Rotate the engine manually in the engine running direction watching the intake and exhaust valves move. When the exhaust valve is closing continue turning the engine until you arrive at the TDC pointer and 0 degree crankshaft timing mark. This will assure you are on the compression stroke. The distributor rotor should be pointing to the cap tower wire that connects to the #1 cylinder. The engine will run 180 degrees out of time (running on the exhaust stroke) but will not have very much power.
If the above is correct then check and record the valve lift for each valve and each cylinder. If the cam and lifters were installed without using the proper break-in lube and not following the critical camshaft break-in procedure will wear the cam lobes very fast. If you reused the old cam and lifters and followed correct break-in procedures and if the lifter order did not follow the same order as removed the cam lobes will wear during the critical break-in. You can place a dial test indicator on the valve spring retainer and rotate the engine for the valve/cam cycle. Depending on the cam lift you have and rocker arm ratio will determine the valve lift you should measure.
If both checks above are within specification, the last item to check would be the installation of the cam chain and sprocket. When installing the chain and sprocket set did you degree the cam relationship movement with the cylinder? If the cam movement is retarded in relation to the piston movement the engine will run but not have very much power.

 

[PeterK]

Try changing your fuel filter. It's a cheap guess and even a little water will plug a paper filter enough to starve the engine under load.

 

[ichthos]

I will do the checks you mentioned, Big 6. Funny you should mention water, Peter. I suspected water early on and put some of the stuff that supposedly "dries" out gas in the gas tank. I didn't replace the fuel filter though. I will try that and see what happens. It may be a combination of issues.
Kevin

 

[DougF]

I always have gotten vacuum connectors from The Roadster Factory. The fit is good.

 

[nissanite]

How long has the engine been out. Fuel with the dreaded Ethanol can phase separate in as short as 3 months. My Jag is running very intermitent, stalls sometimes, runs on 3 and misses sometime. I drained some of the fuel out & it had water and sediments.
The more fuel I run through it the better it runs.

 

[tdskip]

So just to ask, where do you have the timing set?

 

[poolboy]

So just to ask, where do you have the timing set?

My thoughts too. But then I'd just have to go into that timing mark accuracy issue vs manifold vacuum.
https://automotivemileposts.com/garage/v2n8.html

 

[Bremer]

Another vote for timing mark accuracy. Check for black rubber pieces around the front damper pulley which could indicate that the outer pulley ring has shifted against the inner ring.