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Maximum Safe RPM
https://www.slantsix.org/forum/viewtopic.php?t=3123		 Page 1 of 1
Author:  Patrick Devlin [ Tue Jan 15, 2002 6:19 pm ]
Post subject:  Maximum Safe RPM
Quote:
: This sounds like the start of another good
: thread so you may want to start a new post
: on this question.
:
: Be careful to define what you mean by
: "stock" seeing that the 1bbl and
: stock cam really limits the RPM on a
: "stock" SL6.
: DD


Don't mind if I do. What I meant was what RPM is considered abusing the stock engine? Or what engine RPM will ensure short engine life? My engine is stock (stock cam, springs, oiling, etc.), except for Dutra duals w/ 2 2" pipes, Clifford water heated manifold w/ Weber 32/36 DGEV carb...it will still pull past 4000 rpm in 3rd gear. The engine has a little over 130,000 mi.

Patrick Devlin

pwd22@drexel.edu
Author:  dschumers [ Tue Jan 15, 2002 8:27 pm ]
Post subject:  Re: Maximum Safe RPM
Quote:
: Don't mind if I do. What I meant was what RPM
: is considered abusing the stock engine? Or
: what engine RPM will ensure short engine
: life? My engine is stock (stock cam,
: springs, oiling, etc.), except for Dutra
: duals w/ 2 2" pipes, Clifford water
: heated manifold w/ Weber 32/36 DGEV
: carb...it will still pull past 4000 rpm in
: 3rd gear. The engine has a little over
: 130,000 mi.
:
: Patrick Devlin


The motor that came out of my Duster had 160,000+ miles on it. We always shifted it at 4200 when it had the 1bbl on it and 4600 with a BBD on it. If I ran 1/8th mile, I'd run it to 4800 and cross in 2nd gear. I'd say the first thing to go would be the timing chain.


slantzilla@excite.com
Author:  Doctor Dodge (Doug Dutra) [ Tue Jan 15, 2002 9:36 pm ]
Post subject:  Re: Maximum Safe RPM
Quote:
: Don't mind if I do. What I meant was what RPM
: is considered abusing the stock engine? Or
: what engine RPM will ensure short engine
: life? My engine is stock (stock cam,
: springs, oiling, etc.), except for Dutra
: duals w/ 2 2" pipes, Clifford water
: heated manifold w/ Weber 32/36 DGEV
: carb...it will still pull past 4000 rpm in
: 3rd gear. The engine has a little over
: 130,000 mi.


Knowing how short the overlap event is on a stock cam, I would say that the engine will be "off the power" by 4600 or so. The engine can rev-up more but it will not pull strong.

I have installed bone stock SL6 engines into my drag car, just to have some fun and so I don't have to push the car around while another "hot" race engine is being built. I have run these poor old stock engines into high stall converters / steep rearend gears (4.89) and they "jump" and run surprizingly good to about 4800-5000 RPM, then they stop pulling, the engine just goes "flat" about 1000 feet out, the next 280 feet to the finish line seems to take forever.
Funny thing is, I bet you could run the engine like that all day and it would be fine. (as long as it had oil and did not overheat.
SSSOOO go run your set-up WOT and see how far it revs-up, then you will have your answer!
DD
Author:  CrAlt [ Thu Jan 17, 2002 9:11 pm ]
Post subject:  Re: Maximum Safe RPM
in my "ghetto scamp" ive held the gas down at WOT a few times waiting for the light to change...then shifted to drive. Didnt get many people to take me in street races but i didnt blow anything up ether... When I tore down the beat on slant i didnt see anything worn. The motor had 130K on it and the bearings still looked very good....
Now the 7.25" rear end, thats another story :)
Quote:
:
: The motor that came out of my Duster had
: 160,000+ miles on it. We always shifted it
: at 4200 when it had the 1bbl on it and 4600
: with a BBD on it. If I ran 1/8th mile, I'd
: run it to 4800 and cross in 2nd gear. I'd
: say the first thing to go would be the
: timing chain.



cralt@aol.com
Author:  Patrick Devlin [ Fri Jan 18, 2002 1:10 pm ]
Post subject:  Re: Maximum Safe RPM
I'm just glad to hear that I'm not abusing my car any more than anyone else! On the plus side, when stuff breaks it's an excuse to do some "upgrades."
Quote:
:
: in my "ghetto scamp" ive held the gas
: down at WOT a few times waiting for the
: light to change...then shifted to drive.
: Didnt get many people to take me in street
: races but i didnt blow anything up ether...
: When I tore down the beat on slant i didnt
: see anything worn. The motor had 130K on it
: and the bearings still looked very good....
: Now the 7.25" rear end, thats another
: story :)



pwd22@drexel.edu
Author:  Ron Parker [ Sun Jan 20, 2002 4:45 pm ]
Post subject:  Re: Maximum Safe RPM
Patrick I have raced my car for two years in the slant six shootout and it is stock on the bottem end. It runs out of power about 4800 rpm but it pulls to 5200 rpm in the 1/4 mile. so for no problems on a like new engine with only 79000 miles on it thanks ron

rpracing@catt.com
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