Originally Posted by: HK1837 ...
There's nothing particularly special about a Repco F5000 block casting. They were purchased as a raw casting from Holden by Repco Engine company and specially machined, useless protuberances lopped off, oil galleries opened up in places, bored, line bored etc etc.
Ditto the crankshaft, which was a production item offset ground to get below the 5 litre formula limit.
The rods were special Repco forgings, as were the pistons.
I was under the impression the F5000 and the L34 blocks were special cast material by GMH. They introduced the stronger block casting that appeared in normal production with HJ 253 and 308. The F5000 engines had slightly smaller (undersize) bores to stay under the 5litre limit hence the special pistons. The F5000 blocks were cast around early 1973 from memory and lots have a big X in the casting, a few have appeared in L34 which often also have an X across the 308 cast mark.
I can comment on that as I had a neighbour* (he still lives there, i moved away several suburbs) who did his automotive apprenticeship as REDCO
Repco's engine development arm that was involved, as I found out, in the development of both Holden F5000 and L34 engines and some of our chats
when I was a young hoon, just with a licence making 179s go faster were rather interesting
The F5000 block was a standard Holden 308 casting... but made from SG Iron (same as the hipo Chev small blocks used in NASCAR etc)
It was known at REDCO as the 'iron' block and was sent to REDCO unfettled (as cast if you like and untouched) from the holden foundry.
Development of that block resulted in some strengthening (extra material in places) as well as design changes to overcome some flaws
.. most noticably the cracking around the rear main that was fixed by enlarging and adding external webbing to support the rear main area
as well as thickening of the deck to also prevent cracking
These design changes carried over into the L34 engine block.. but this was made from the usual Holden 'grey'cast iron as used in all Holden motors
at that time. These blocks were marked with an 'X' at the back of the block to distinguish them but In the end, ALL 308 blocks got the strengthening
... it was just simpler for Holden to make one only sand core to cast 308 blocks in the Pt Melbourne foundry.
* Mr Berryman (as I called him) finished his apprenticeship and then after a few years at the start of the 80s went and worked for Repcos
engine parts plant at Maidstone. Very dull and boring he did not stay long but went and opened up his own 'engine' shop in Moorabbin
(not far from home). He built engines for me, did all manner of balancing (tailshafts, cranks, driveshafts etc) and also did the machining and
balancing work for Larry Perkins after he set up Perkins Engineering at Moorabbin airport
Edited by user Tuesday, 29 December 2020 5:49:57 PM(UTC)
| Reason: spelling