Question? A 66's 200 Bottom-end Capabilities/Limits.

MT63AFX

Well-known member
Since the OE 200 shortblock in my 66 Falcon SW has the seven main caps, what is the rpm limit before an OE rod/piston "exits" or "quits playing nicely" with the rest of the rotating assembly? The engine has a 250 head with 5.0/302 valve springs, valve stems are 11/32" and 5/16", cam is 268S from Oregon Cams (.440"-ish advertised lift), and a Weber 38 carb. Don't know for sure where cam peaks out at, but it hit 5,000rpms the other day and sounds like it still had more in it, thanks, RodC.

http://www.supermotors.net/getfile/1024 ... g_0237.jpg
 
jack clifford(rip) used to claim the 200 could easily handle 7000rpm given proper valve springs.
 
I'd say even more if you can control crank oil windage.

Old Hydroplane racers often had six Amal Carbed 155 versions of the 144 with four bearing cranks did 8400 rpm. Knotty's 1961 XK Falcon does 280 hp and revs at 7500 rpm with a four bearing crank.

A Holden XU1 with 10 counterweight crank does 7500 rpm with 202 cubes and 1.9" crank pins.
The Argie 183 cubic versions of there medium deck 188/221's run to 9500 rpm all day

The Aussie 250 can run to 7500 rpm.

Although this one didn't


Legoutabed.jpg


http://www.fordsix.com/forum/viewtopic.php?p=195427

The best I6's run a fully counterweighted crank, like In the 1994, the EF crank got reworked to 12 counterweights (Holden XT5/XT6's had 12 counterweights in 1980, so not cutting edge). All Ford small I6's have had 8 counterweights since 1960 to 1993. The harmonic balancer was changed to a two element item.

The bearing clearances were tightened up.

Peak revs increased to 5500 rpm, up 10% or 500 rpm.



http://www.fordsix.com/forum/viewtopic.php?f=3&t=69393
 
I'm impressed, thanks for the responses gentlemen, :beer: . I guess I'll move the redline on the tach from 4,500 to 5,800. I'm not certain where the springs' limit is but will find out once I check the rocker arms' alignment over the valve tip (one in my photo link looks abit askew, :wink: , RodC.
 
Running a Clifford built U.S. 250, shift-light is set for 5000 and redline at 5500 but will sweep past 6K often , with a 200, and sufficieant build confidence I think the 200 will run out of breath before breaking any bones...

haeve fun

Ford C8DE 250 Six; Bored .070 over with TRW AMC 258 Pistons, Clifford Shot Peened Rods, Clifford 272H Cam, Cloyes timing set, Melling blueprinted HP oil pump, Fisher Dampener, Offenhauser Tri-Power 3X1 aluminum intake manifold adapter w/log Hi-Rise Plenum - Holley 4412 500CFM performance carb, GM HEI ignition trigger, Champion racing spark plugs.
 
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