Hi All, Can anyone advise if 1973 246 Dino's had hardened valve seats ex Factory? And Were USA fuel's unleaded in 1973 across the whole of the USA or only in certain parts or not at all and what was the common octane of the fuel you would buy then? Thanks Steve Sent from my iPhone using Tapatalk
I believe the valve seats are manganese bronze. Discussed here: http://www.ferrarichat.com/forum/technical-q/265345-looking-experienced-ferrari-machine-shop-press-valve-seats-out.html
You did mean Valve Guides I assume? Would you know anything about the Valve Seats? Sent from my iPhone using Tapatalk
Basic question; are the bronze valve seats adequate for today's 10% Ethanol unleaded gasoline, or should the valve seats be replaced with valve seats of a different alloy?
Not to hard to find ethanol free gas. Several gas stations in my area have it available in 90 octane. I don't think it would be much of a factor anyway. You could always go with additives. The Lancia Stratos engines were Dino engines and they ran the dog p$$ out of them when rallying. The valve seat material is pretty good.
he's in New Zealand, they appear to have plenty of ethanol free choices, so it really just boils down to additives or no additives. I ran unleaded premium in my Dino without issue. It had the factory seats and guides and when we tore it down they looked fine. The mechanic did fine tune the seats at that time. Not sure if we replaced the guides, but a little voice in my head says yes. D
Hi All, thanks for the help. Yes I'm in New Zealand with a LHD US spec Dino. NZ stopped using Lead in Petrol in 1996 which is required for Valve seat lubrication, unless the seats were hardened. My Dino was imported to NZ with only 12,788 miles. It has been Targa raced a number of times and now in my care, has completed just over 23,000 Miles. So about 12,000 miles on unleaded fuel, and the expected high revving environment of car racing. 3 cylinders now have low compression so we have recently stripped it down, cleaned it and have now completed detail checks on everything. The result is, (fortunately or unfortunately, however you see it), - it was Never run in properly from new! Otherwise the engine is like new! So apart from sorting rings for the low compression we do not really need to do much. The Valve seats will have been work hardened but for the type of driving I wish to do, on unleaded fuel, we were wondering if we needed to replace the Valve seats when we do rings etc. and given the time it takes to get the engine in and out we do not want to skimp on anything as that would be counter productive. Regards Steve Sent from my iPhone using Tapatalk
Very early 206 dino and a few 246 had bronze valve seats. You can but any size valve seat you need from any parts supplier but you need a competent machine shop to turn them down to fit on the exterior and interior and some times the width. I installed several hundred valve seats in my time as a automotive machinist. Cold pressing is the best but be sure to polish the od to mirror shine with a chamfer on outside to aid in a clean entry. good luck and contact me any time if you would like. clay Burlingame calif
