/4 shortblock assembly + HP limits, case, crank and rods....how much abuse?? Options

[Mueller]

Let's say we take the stock heads and cylinders out of the picture and use heads/cylinders that are overkill and robust....

what is the next weak link in the motor?

are the rods going to fail once we start hitting the 200+hp mark?

will the stock crank turn to putty at 7000rpm?

what about the case??


at what HP range before it cannot hold everything together and gives up scatering it's internals all over???

[Brett W]

I haven't heard anyone say that Pauter rods aren't anything but problems. I prefer Crower for most engines, Eagles aren't bad but not available for our motors. I agree on the Carillo statement, heard both sides. Heard good things about Oliver and Cunningham. My SOHC honda engine runs a 1.77 rod journal, much smaller than the factory 2.0 journal size. It turns 7000rpm on a daily basis without any problems.

Haven't decided who to go with for this 1.9 monster. The 1.8 has a rod ratio of 1.95 while the stock 2.0 has a rod ratio of 1.84. If the engine is stroked to 2270 with 78 crank and the stock rod, the rod ratio goes to 1.678. Although not really bad it is a little below optimal. Some factory production motors are running 1.55 rod ratios with much smaller rods than what the factory put on our motors.

I would like to use something in the 1.75 range (115mm rod) on the 1.9 but I may just work a factory rod over and see what happens. The factory ports aren't big enough to support a shorter rod ratio. I am afraid dropping the factory rod ratio that much will cause the engine to lose power due to the lack of breathing area. we'll see though.