from: [email protected]
to: [email protected]
subject: pushroddin' at random

 Amusing small block Ford test:  
    guess which pushrod is correct for *your* application:

Ford Motorsport Catalog (1998)
- 5.0 roller                      6.272 (measured 6.251 across oil holes)
  '62-'69 221-302                 6.804
  '65-up 289/302 w/351W heads     6.905 (production heads)

Summit 1998 
- '63-'68 221-302                 6.825 - quotes Crane
- TFS' shortest listed pushrod is 6.500

Comp Cams 1997 catalog
- "High Energy" series pushrods  (not hardened?)
  7826-16 255-now, flat tappet    6.876
  7827-16 302 OE hyd roller '85+  6.250
  7828-16 '68-'85 .060 short      6.816
  7829-16 '68-'85 .060 long       6.936
  7819-16 302 retrofit            6.400  (presumably for hyd. roller -dw)
- "Magnum" series pushrods
  7632-16 '62-'69 221-302         6.804
  7631-16 '69-'85 non-roller      6.886
- "High Tech" series pushrods
  7929-16 '62-'69 221-302 std     6.800
  7930-16 '62-'69 221-302 +.050   6.850
  7933-16 '62-'69 221-302 +.100   6.900
  7930-16 '69-'78 255-302 std     6.850
  7935-16 '69-'78 255-302 +.100   6.950
- bulk pushrod listing (High-Tech)
  7751-16 6.200
  7917-16 6.250
  7752-16 6.300
  7753-16 6.350
  7754-16 6.400
  7766-16 6.450 ***********  BINGO!
  7767-16 6.500 
  7768-16 6.550 
  7769-16 6.600 
  7770-16 6.650 
  7771-16 6.700 
  7772-16 6.750 
  7929-16 6.800
  7930-16 6.850
  7933-16 6.900
  7935-16 6.950
- Comp cut-to-length 7714  6.00-7.00" 5/16"       7716 8"-9"

Isky 1994 catalog
- 1235-L Minus .050 (yes, that's the part number!) 6.450  
  (oddball roller/rev kit application for small block Chevy)

Crane 1993 catalog
- FireBall pushrods
  '63-'68 221-302    6.825
  '69-'86 2550302    6.905
- bulk pushrod section
  '63-'93 221-302    6.812 (except hydraulic rollers)
  '68-'87 255-302    6.480 (Crane hydraulic retrofit w/Ford rockers)
  '77-'87 255-302    6.680 (Crane hydraulic retrofit w/Crane rockers)
  '85-'93 302        6.258 (stock hyd roller, stock pedestal rockers)
  '85-'93 302        6.375 (stock hyd roller, Crane rockers)
  '85-'93 302        6.163 (hyd. roller, FireBall [Dart] heads)
  '62-'93 221-302    6.875 (SBF w/351W heads)

Lunati 1986 catalog
- 289/302, all hydraulic lifter 6.776

Speed Pro 1997 catalog
- 289   6.775
  302   6.775 or 6.885      "Speed Pro"
        6.250, 6.800, 6.876 "stock type"
- Speed-Pro has cut-to-length pushrods RP-8000-R 289/302, RP-8001-R 351W/SBC
  (Speed Pro says one end is hardened for guide plates)

  
The engine I'm working on (5.0 roller w/351W heads, Comp stainless rockers)
wanted 6.435 across oil holes (6.451 nominal)

 Now, all this assumes .030 lifter preload.  David Vizard says most
hydraulic lifters only lose .005 or so, depending on the RPM, so if
you had a big handful of preload like Fireball Korb has been talking about, 
you might need +.100 pushrods even with *all stock* parts. 

 I've already determined the Comp stainless rockers have different geometry 
from the stock Ford cast rockers.  Whether the cast and stamped rockers 
differ, and how other brands of rocker differ, is left as an exercise for the 
reader.  I'm not even going to get into the small base circle, reground 
performance cams...

 What was that thread a few months ago about "noisy rocker arms"? 

 Do you feel lucky, punk?

[email protected]======================================
I've got a secret / I've been hiding / under my skin / | Who are you?
my heart is human / my blood is boiling / my brain IBM |   who, who?
=================================== http://home1.gte.net/42/index.htm