Topic: 20r from hell?

[sirdeuce]

I've built high revving R engines in the past, for around 8000RPM I had a 22" primary with a long collector and isolated runner. Made a big difference above 6000RPM.  Forgot to mention the need for camming in the 300 degree range.  But I do agree with the 6500RPM range. For a Celica, I would build for a 7000RPM limit with a split duration cam 280/270 and open the exhaust and use dual carbs. If all is good in the rest of the build and tune the power would have a decently flat curve. The stock rods will go 7000RPM all day, but anything over 7200RPM they become a time bomb! Concentrate on hooking the meat to the ground and lightening the car. The old R is torquey enough to keep the 3.73 gears for the 1/4. Play with the tire diameter  instead of changing gears for now.

[sirdeuce]

I've been there, done that. An 8000RPM 22R is a beast to build! the attention to detail increases exponentially  after about 7000RPM. To be honest, my favorite was my first 94mm stroke, 93mm bore 20/22R I built in '87. The crank was welded and ground offset and lightened by 3lbs. The flywheel was a custom piece at 12lbs. the head had TRD over size valves for a 22R, 47in, 37ex. 10.3-1 comp ratio. Side draft 40mm carbs and a big exhaust system, just to paraphrase the build. It was in a 1981 Celica hatchback. Thing pulled from 2000 to 5000 like crazy! Ran mid 13s. The torque was ridiculous! The horsepower dropped off hard at 5200RPM. It was as reliable as the sun and moon! You build an 8000RPM 'R' and it's reliability drops off radically. An engine for a lightweight Celica is worlds apart from a 4X4 truck though.

[79coyotefrg]

those 94mm pistons are serious  but I agree with most of what you said.   
Someday I'll get another Celica like the 80 GT I had.  I have a early head with no pwr steering mounts that I will use along with the dual weber sidedrafts   300* cam   that thing will be a fire breathing little dragon car

the 20/22 hybrid I had in my truck would have probably held up had I used dual valve springs and titanium retainers.

[sirdeuce]

Dual valve springs are good at high RPM high lift apps. I've had good luck using asymmetric wound springs in the past, like 'beehive' springs. I had the shops install Buick 231 V6 beehives in my last 22R screamer. No valve float at 8500RPM, No power, but it sure was nice to hear the beast screaming like it was in pain. 

[79coyotefrg]

Dual valve springs are good at high RPM high lift apps. I've had good luck using asymmetric wound springs in the past, like 'beehive' springs. I had the shops install Buick 231 V6 beehives in my last 22R screamer. No valve float at 8500RPM, No power, but it sure was nice to hear the beast screaming like it was in pain.