Let's talk about something more interesting. Suppose I had a TR 4-cyl that I wanted to hop up a bit, what should I consider doing? For this exercise, you can assume the following:

1. Going to rebuild everything anyway

2. Desired outcome is a fun, street-able, street-legal (at least at a casual glance) car

Starting from the bottom & going up(in no particular rank):

1. Optional finned aluminum oil sump

2. Cross drill crank oil passages at bearings, have crank nitrided

3. Replace stock fan with harmonic dampener meant to tame the harmonic just over 5000 RPM

4. Lightened or aluminum flywheel

5. 87mm pistons & liners

5a. Balance rotating parts of the engine.

8. 280 degree cam ground to peak at 6000 RPM and have a long flattish top

9. New lifters that have been hardness tested to Rockwell 54 hardness or above

10. If you have the bucks get Moss's new aluminum head, if not you want the latest TR4A head with the 1-1/2 dia intake ports.

For a stock head:

11. Shave head per Kas's competition prep book for 10:1 compression, including cutting away the shrouding around the spark plug

12. Open up the exhaust passages slightly

13. Open up the intake and exhaust pockets slightly and install hardened seats upside down so that the seats slants from the valve pocket to the chamber. Grind the valve seats. The result you are looking for a wide smooth valve pocket and a hardened seat that acts as a venturi to speed up the mixture past the valve opening.

14. GO to an oversize exhaust valve.

15. After you cut out the head shrouding around the head you need to match the head to a new metal head gasket and carefully cut away the part of the gasket that would be in the chamber. This will ruin the seal of the inner sealing ring but leave the outer one intact.

16. Test install the new liners with the figure 8 gaskets installed. Carefully check the height of each installed liner. Each liner needs to have less than 0.002 height difference from the others and between one side and the other. Sand the figure 8 gaskets as needed to get exact liner height alignment.

17. Next, glue a piece of copper wire that is .012" thick into the intact sealing grove of the steel head gasket with contact cement before installing the head gasket. Use silicone sealer sparingly around the coolant passages at instillation. NOTE: If you install bronze valve guides they will need to be reamed to a slightly larger dia than the manual states because bronze expands more with heat and they can seize valves.

18. Use exhaust headers, and loose the resonator

19. SANITY CHECK: SUs will work very well with the least amount of work and can get very close to a properly set up pair of Webers performance wise and may tune better for economy. SUs will cost you less to set up and should be the choice for sane rational people. Others go on.

20. If sanity is lacking proceed with a pair of 40DCOE carbs on Pierce Manifolds. You can buy a set from Pierce Manifolds in Gilroy California or get a set up from Moss. Buy them with 34 chokes, 4.0 or 4.5 auxiliary chokes 50F9 idle jets, 140 main jets, 170 air correction jets, F15 emulsion tubes, 45 acceleration pump jet, 50 accelerator pump intake discharge valve and a 2.00 needle valve IF you are building the engine per my description. This will give you a good starting point for fine-tuning and should provide a runnable engine as is.

21. Go to TWM for the shortest stacks they have for 40 DCOEs and for the shortest single itg air filter they have to fit your engine.

22. You will still need to modify the front bottom of the filter for clearance in a TR3. I cut the front to rear stabilizing rods off the filter frame and clamped the top to the bottom with hog rings. You only have to modify the front bottom corner.

23. Get the Mallory breaker less distributor and set the timing for about 8 - 10 degrees BTDC and about 33-34 degrees full advance. An engine with Webers needs lot of initial advance to work properly. Not enough and the carbs spit at idle.

24. Stay with the stock fuel pump. It delivers perfect pressure for both SUs and Webers.

25. Use competition springs and valve retainers.

26. If you have shaved the head, use shorter hollow tubular push rods.

27. If you plan on spending any time around 6000 RPM get the special rocker arm pedestals that support the ends of the rocker arms. Replace the springs between the rockers with copper tubing cut to space the rockers properly.

28. You can add one of this finned aluminum valve covers & a breather if you wish.

This should provide you with a nice street engine that is quite dependable. Anyway that should get you a TR 4 cyl that is fun to drive on the street that can get out of it's own way.

TeriAnn Wakeman
Her TR3 web pages