I know it will do at least 10,500 in 1st and 9500 in 2nd gear, is that really close to the point where the engine just grenades? lol And yes, revving that high does dramatically improve your quarter mile times, and there is still lots of power up there... i'm just wondering when its gonna let go, lol. (perfect opportunity for a rebuild with bridgeporting )


and if it does blow and i have to rebuild it, what are the best things to do to help the engine cope with ultra high RPMs?

 

reccomended not exceeding 8500rpm... 9k is pushing it, and 10.5k is just RETARDED on a stock engine... The E-shaft will flex and bottom a rotor out on a housing, destroying the housing, rotor, and all seals.

On a stock engine, peak HP is at 7500rpm or so I believe, so there's no point in revving past 8500...

When you rebuild (notice I didn't say if), hardened stationary gears, carbon apex seals, clearancing rotors, etc, are all good measures to make a high-revving engine (peripheral port or bridgeport)

 

Yea my advice is if your gonna build the motor build it now with the hardened gears so you save the housing s rotors and seals.


Otherwise when it does let go it will be a bunch of worthless parts.

 

perhaps I shouldnt have said rebuild, I should have said swap in another motor and bridgeport that, and it probobly woudnt even go in this thing, the car is so badly rusted out I'm not even sure if theres a point to keeping it.

 

Well don't blow the engine or rev it past 8000rpm unless you want to make it unusable, take it out and put it into a car that isn't rusty? If you want to have the novality of high reving, do as mentioned above, hardened stationaries, carbon seals. And if you want power up there, bridgeport, j-ports, perpheral it. Just don't intentionally break the engine, 1st gen 12a people on this furum have a high demand for used good rotor housings especially... should you choose to part out the car. Most would take offence to breaking good parts intentionally.

 

Do you want the short or the long answer?
Short answer: punching the engine probably wont' blow it on any given day.
Long answer: This will, however, significantly reduce the life of your engine. If you are wondering how I know this, just ask man

 

Past 8500 your pushing it.Eccentric shaft flexes,and the Apex seals resonate(you see some fine nail marks onthe surface of the rotor housings)If you break a apex seal at that high rpms,then you can basiclly throw it away.

Why would you do that to a perfectley good engine?Its not even ported.....allready stopped at 7000....

 

sorry, its just gotten comical how many things are broken on this car. Maybe I will part it out sometime in the near future, she's about reached the end of the road

 

7000

 

stock 8,000
streetported 8,500
bridgeport 9,000
p-port 10,000

my car- bridgeport turbo 10,800 and still pulling on the dyno!

mmmmmmm, it purrs

 

680rwhp12a, I assume you did more than just porting to make it safe for the engine to rev that high, even if the ports will mean it makes power up there. What internal mods have you done? Hardened Stationaries? Carbon seals?

 

My thoughts exactly browney. Sounds like a bit of misinformation to me. Just because an engine is ported and can make power up high doesn't make it safe to do so. Clearly it's the internal mods that make it safe, not the porting.

 

screw the motor. what happens if the clutch lets loose on these ventures. someone give him that vid of the blue 1st gen at the track doing the burnout. weeeeweeeweeeweeewweeeweeeweeeBOOMweeeclunk

 

You are asking for trouble past 8500

 

I have a 81 12a with 70K original I took to a mechanic with Carb problems.... While I was standing next to the car I watched him bury the tach several times while the engine was cold in attemp to clear the clogged carb.... What kind of problems might this cause....... It seems to have devoloped uneven idle runs rough at speed and does seem to have allot more oil leaking near the dowel pins... What should I expect?

 

I'm not sure on the problem... but you should have smacked the mechanic for redlining it cold

 

No doubt. I hope you didn't pay for any work that guy did.

 

he will pay for what that mechanic did.... the work of pushing the pedal down, and FRYING the motor!

















stupid mechanics.... iiick

 

1780982342387462364x10^109718469186348197498172491 872497 radians/hour

 

Thats what I was afraid of..... Grrrrr... I am affraid that the life of the motor has been greatly reduced in ran as smooth as glass prior to that day.... I sat in it while it warmed up several times and it never skipped a beat now I fear it will die at idle form the missing.... It seems to fluctuate at speed as well... So sad it was a beauty... 2nd owner garaged since new with 52 K when I bought it now it has 74K with a motor thats ????? Shall I drive the remaining life out of the motor or is it more re buildable as it is?

 

BTW.... Thanks for all the info ...what a great site very informative...

 

if this is true then why do dyno sheets show a drop off above 6 k on a stock port?

 

Please, please don't blow a good 12a..... I might need those rotor housings one day!

 

I dunno, but I was consistantly 2-3 tenths faster when I overrevved it than when I shifted at redline.