View Full Version : Yes Virginia, There is a heavy duty Truck Engine

01-01-2009, 11:30 AM
This is from a post a while back on the old Studebaker Forum. Some here do not believe there is such a thing as a heavy duty Truck 289:

It is not detailed in the car parts book, it doesn't even mention heavy duty engines or cloverleafs but the truck book does:

"These engines and blocks are equipped with heavy duty main and
connecting rod bearings and chrome faced top piston rings. Parts #
1686288 (259) and 1687546 (289) also include aluminum camshaft gear.
NOTE--Al heavy duty engines can be identified by the clover leaf
stamped on the engine number pad."

From Page 16 , last paragraph Studebaker Trucks Parts book 57-61.

So it would seem all cloverleaf engines are heavy duty truck engines
either OEM or NOS replacement. I'm still trying to remember what the
"keystone" symbol means on the engines.

1957 Packard Clipper
1958 Golden Hawk
1963 Daytona Convertible
1963 R2 Daytona
1963 R2 GT Hawk
1963 R1 Wagonaire
1963 R4 Avanti
1964 Champ
1966 Cruiser

01-01-2009, 12:35 PM
My 63 R2 Avanti has a clover leaf engine.

01-01-2009, 12:51 PM
Please post when you find out what that keystone means ...I have one of them

[IMG]http://i99.photobucket.com/albums/l300/2R5/smallchamp-1.jpgHome of the Fried Green Tomato

1960 Champ
1964 Daytona HT

01-01-2009, 12:57 PM
So if I understand it correctly, there are HD truck engines, based on the internals- but no such thing as HD truck blocks, correct?

It seems the blocks are all the same, but what earns the cloverleaf is not simply replacement status (as I always understood), but HD internals.

I think the post I read questioned the existence of HD blocks. Based on your quote, non-existence appears to in fact be the case.

(Of course, I freely admit I might have this wrong.)

Robert (Bob) Andrews Owner- Studebakeracres- on the IoMT (Island of Misfit Toys!)
Parish, central NY 13131

"Some people live for the rules, I live for exceptions"- 311

"Do they all not, by mere virtue of having survived as relics of a bygone era, amass a level of respect perhaps not accorded to them when they were new?"

01-01-2009, 01:43 PM
quote:Originally posted by 2R5
Please post when you find out what that keystone means ...I have one of them

Me Too.


If that isn't one side of a Keystone, it surely ought to be....

Tom Bredehoft
'53 Commander Coupe (since 1959)
'55 President (6H Y6) State Sedan
(Under Construction 571 hrs.)
'05 Legacy Ltd Wagon
All Indiana built cars

01-01-2009, 01:58 PM
And the HD truck engines are the same internally as the Avanti R series engines (as far as the HD components).

'57 Transtar Deluxe
Vancouver Island

Are you planning to attend the NW Overdrive Tour in Parksville, BC
May 23 & 24, 2009?</h5>

01-01-2009, 02:09 PM
So whats the deal with those keystone stampings ? I have one in my '64 Daytona

[IMG]http://i99.photobucket.com/albums/l300/2R5/smallchamp-1.jpgHome of the Fried Green Tomato

1960 Champ
1964 Daytona HT

01-01-2009, 02:54 PM
That Studebaker built some V8 engines with uprated parts is not exactly new news. There were Studebaker V8s built for trucks and R-series cars with uprated parts installed. A search here will bring up dozens of prior threads detailing this.

As described in the original post, some truck engines and the R-series engines had uprated parts installed in their blocks, but all the blocks came out of the foundry equal. Until someone can show a reputable print reference to the contrary, there were NO such thing as a heavy duty truck block. AFAIK, no matter what is stamped on them and no matter what cubic inch they ended up being, and no matter which vehicle received the engine, all Studebaker V8 blocks from '55 on to the beginning of full flow and then all full flow blocks began life as the SAME casting.

thnx, jack vines


01-01-2009, 03:05 PM
Thank you Jack.
No, Virginia, there were NO HD empty blocks.
The "keystone" was once explained to me as something to do with the foundry..I have seen the keystone mark on engines in the thirties.
Nobody has ever come up with an absolute on that mark.
I don't remember if there were clover leafs with fitted pistons only...but I kind of doubt that as the cloverleafs had more than just chrome rings as was stated.


01-01-2009, 03:40 PM
There were heavy duty 259 and 289 engines. The heavy duty engines included: chrome top piston ring, heavy duty inlet and exhaust valves, roto-caps, tri-metal connecting rod and intermediate main bearing inserts, aluminum timing gear.

I used to like to use those roto-caps on any V8 when doing a valve job.

Gary L.
Wappinger, NY

SDC member since 1968
Studebaker enthusiast much longer