What do 7k-8k-9k+ RPM motors all have in common?

[Caveman Tony]

$$$$$$$ ;D ;D

Seriously though: Forged everything, valvespring pressures that could hold up a semi, yada, yada, yada... but is the simple answer the whole answer?

[realsteelfreak]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Holes in the oil pan?

[SpiderGearsMan]

Re: What do 7k-8k-9k+ RPM motors all have in common?

HOW MUCH YOU WANNA SPEND ?

[1988montecarloss]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Holes in the oil pan?

thats what my monte has

it was about a 7500rpm motor ;D

[TheSilverBuick]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Brushes and windings?

[Brian Lohnes]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Lots of PRECISION machine and assembly work.

[kelly andersen]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Lots of aggressive disassembly when you keep pushing them that far. LOL

[squirrel]

Re: What do 7k-8k-9k+ RPM motors all have in common?

What do 7k-8k-9k+ RPM motors all have in common?

they sound good?

[realsteelfreak]

Re: What do 7k-8k-9k+ RPM motors all have in common?

rat-tat-a -dat-kla-plunk :o

[Barry Donovan]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Lots of PRECISION machine and assembly work.

yep. no doubt.

big bore little stroke, solid lift (302 chevy ;D).. there is several reasons not to concentrate too much on machining, by having an intention to wind up anyway from the beginning.

a 3 main boxer can go there just keeping clean. I know mine is near 9000.. can't load it of course, only dead rev. 7000 if lucky in a low gear like 2nd or third. :

and here is my most recent dainty headgasket. :o



I am into felpro now (good opinions from the turbo world of same engine) I was glad to take this apart on my own. I even updated 2 of the bolts. A mechanic would have ganined 500 bucks and slapped the same stuff back together.
I guess that is a factor in common: you are most likely on your own if you have a 7-8-9k rpm.


why rev an engine that was meant to be more a diesel than anything?
unless $$$$$$ is something you like to give away.
the high rev 8s for this today are foriegn or extinct american...I would still stop in the mid 5k rpm, on bigger strokes..else to hell with it.

here is another "real" 302 z28 (I watch this you tube channel for the cars)

http://www.youtube.com/watch?v=Tc_xALMl2C4

[JeffMcKC]

Re: What do 7k-8k-9k+ RPM motors all have in common?

I shift mine at 8300 and at least on my end the 7 K one is a walk in the park, making power to 8k is a different story, holding together is not a issue. Making power to 9k and keeping the pushrods in it and valve train stable is a real job with a big bore short stoke its not that hard to keep it together as a total package it takes some care and its not a do burnouts for your friends motor.

[milkovich]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Like Jeff said, getting the bottom to hold together on a short stroke engine isn't that hard but keep in mind forces add up exponentially. Piston acceleration at 9k is almost doubled from 7k. Religious attention to machinework/assembly/maintenance will get the bottom end to last a few seasons... but you do that anyways on something you want to last any ammount of time.

The top end is another story. The best right components and painstaking attention to detail and geometry keep those nightmares alive. The spring pressures need to be checked all the time. Those circle track guys don't dump their valvetrains on ebay every year just because they're nice.

[jays67]

Re: What do 7k-8k-9k+ RPM motors all have in common?

yep Jeff is right on the valve train my 301 and my 331 were/are rpm motors the 301 finaly broke when a wrist pin walked and ate the block

I would leave at 8500 with a stick and shift it at 7500 (makes ur teeth hurt when it is wound up in side the cab lol)
I was trying to do it as cheap as I could and it was common for me to brake rocker arms in half and spit push rods through the valve covers opps


the 331 is still alive and goes to 7500 often but it is more a road race set up car so not quit as hard as the 8500 launch
;D

[LS1 ZR2]

Re: What do 7k-8k-9k+ RPM motors all have in common?

I shift the 427 LS motor with a 4" stroke at 7500 rpm. I used to shift the 540 BB in my Monte Carlo at 7500 as well.

[jcharliem]

Re: What do 7k-8k-9k+ RPM motors all have in common?

Trick valve train, forged bottom end, and a decent assembly of the mill.




<<---- This thing will bounce off the 8k rpm limiter. But, the valve train is definitely the weak link in its chain.