View Full Version : Cloverleaf engine question?

05-26-2010, 11:01 PM
I tried the search and came up with skinny's posts on his 61's. But are all Cloverleaf engines 289's or just factory replacements ?
I just brought home the 61 2Dr sedan that I bought yesterday from Bob Peterson. While unloading the car I went to check the exhaust heat riser for free movement. I was surprised to see an oil filter and cup style core plugs underneath. It has a full oil flow engine. After cleaning the engine number pad with a wire brush that I thought was blank. I found a Cloverleaf. This was a surprise because valve covers for it are 61 Orange & the oil fill pipe has a part of the filter mount on it. I removed a spark plug and tried to look for a dished piston with no luck.


05-26-2010, 11:23 PM
Some of the cloverleaf blocks were definately 259's. My understanding is the cloverleaf designated a factory replacement engine and should have been renumbered with the cars original engine number. Seems most never got renumbered. I have also heard that all cloverleaf blocks were built to HD truck standards but cant confirm that. Steve

Skinnys Garage
05-26-2010, 11:26 PM
Could be either, the cloverleaf was used on Heavy Duty replacements. My cloverleaf in the '61 is a HD partial flow 259. I also have a non-HD (no cloverleaf, no numbers) partial flow replacement 289 in my '62 Cruiser. Both engines do have a faint "keystone" (inspection stamp) that can be seen easier with a bright light. If you can find a piston closer to the top, you should be able to see the ridge of a dished piston right about in the middle of the spark plug hole if it's a 289. I'd guess with a HD full flow, chances are better it's a 289.

05-26-2010, 11:58 PM
Thanks guys, I'll try to get some better light in the plug hole tomorrow. Bob told me it was a 259 2 barrel before I bought it. But the engine number pad looked dirty and blank to me. The clover leaf is way off to the right on toe pad. I don't think he was aware of the full flow and clover leaf engine. He never mentioned it in the e-mails.


05-27-2010, 12:04 AM
Were there "Cloverleaf" Champion sixes (to designate heavy duty), or does the cloverleaf always appear on V-8a?

05-27-2010, 12:40 AM
Gordon bring back my engine I sold you a 259, you must have changed it when my back was turned, It is news to me about it being a clover leaf but then I didn't really check it much, win some loose some, hope it works out for you...Bob

Dan Timberlake
05-27-2010, 04:51 AM
It's pretty easy to stick a LONG coffee stirrer in a plug hole and rotate the crank thru a revolution or 2 to measure the stroke to an 1/8 inch or so.
3.25 inch for 259. A little over 3.5 inch for 289.
My Hawk has no fan shroud (yet) so I used a 1/2 inch drive ratchet with giant socket on the crank bolt, while keeping ahold of the stirrer at all times. Try to hold the stirrer parallel to the cylnder centerline for accuracy.
Some cars can be turned with most spark plugs still in by a wrench/ratchet used gently (slowly) on an alternator or Power steering pulley bolt/nut.

Also useful for a rough check of the TDC mark.

Skip Lackie
05-27-2010, 07:38 AM
Were there "Cloverleaf" Champion sixes (to designate heavy duty), or does the cloverleaf always appear on V-8a?
All postwar Stude replacement engines were available with HD components, and all HD engines were identified with a cloverleaf. Clearly, they were intended for use in trucks and taxicabs, but many ended up as replacements in cars, too. All 6-cylinder cloverleaf engines had HD valves and chrome top rings. The 246 cu in big six engines also had exhaust valve roto-caps and HD valve springs. The V8s had HD rod and main bearings and chrome top rings. Some had aluminum timing gears. The 57-61 truck parts book lists the part numbers.

05-27-2010, 05:00 PM
Thanks for clarifying that for me, Skip!

05-27-2010, 05:31 PM
Were there "Cloverleaf" Champion sixes (to designate heavy duty), or does the cloverleaf always appear on V-8a? I recently sold a OHV 6 that was a clover leaf. It had the alum. timing gear. NT