I have heard that the crank on the 1500 spitfire engine is fragile. Indeed
the SCCA FP car we bought had just thrown a rod and been "professionally"
rebuilt. We ran it as is (learning curve, trust only yourself and check the
machinists).
When we tore it down we had a cracked third throw. The "professionals" had
installed the rod cap backwards on that cylinder and pinned the vibration
dampener.
We made sure the oil passage to the center main was opened up al la the
Triumph competition book. We have also had the crank nitrided and cross
drilled.
We have heard several other techniques that have been applied. These are
1) steel main caps.
2) the small bearing 1300 allegedly had an oil grove behind the center main
bearing that supplied additional oil to the second and third thows. The
1500 and large bearing 1300 did not have this. It has been suggested that
the center main be grooved like the small bearing 1300. I really do not
like this as I prefer not to have high pressure oil behind the bearing.
3) in addition to the steel bearing caps install a girdle for added
rigidity.
4) cross drilling the rod journals (done).
5) use a GT6 oil pump.
7) teflon coat the bearings (done)
8) make the trust bearings 360 degrees rather than 180 degrees.
Comments on all or any of these solutions are welcome. Alternate
suggestions and comments on them are welcome.
We currently turn the engine up to about 7200, we would like to get it to
8000 on occasion with anew cam and have it live.
Thanks in advance
Matt Matthews
Houston TX
|