Does anyone have someone that can shorten and re-spline a drive shaft???
I have a 25" drive shaft from a 3.4v6 Cosworth Merc that I need shortened and then re-splined to use in a 20" application.
Any help is greatly appreciated.
Yes,...I still love my inline-6 beasties, but this Mercury 'White Elephant' fell into my life, and I just want to make it right. Someone previously must have cut off a 25" drive shaft & selected to cut in the new splines with a hand-held die-grinder.
I just can't reassemble as it is.
I believe Chris Carson Marine in FL does that. Lots of the S&F guys need shafts shortened to fit the real short V-6 race mids. I'm not sure if he cuts and welds as that keeps the hardened splines from factory, or if he resplines or has a sleeve to connect the two halves. Chris has been around a long time racing and has tons of fun inline race stuff from back then. He was interested in my Switzer a while back so I had a chance to talk with him a while.
You may know, Merc actually welded their shafts for a while as an improvement an the failure prone all steel shafts. They put a SS lower half that's always in the water and welded it to a steel half up top where hardening is easier and I guess back then SS was pricier. You'll notice the split in color just above the water pump. Generally between like late 60's to early 70's then they went all stainless ( finally!)
Geeez ya scared me for a sec not seeing a pic of an inline! Ha!
God, I remember that bastard. Drank fuel like I owned a well and did not have a great top end, but the torque!!! Great cruiser engine but useless on performance boats. Getting parts will probably be an issue as they were not around long, so don't get too wrapped up in it Thom. May not be worth it.
Hi George,...Yuppp - that is all I've heard about the beast.
Gas guzzling & will self destruct if pushed over 6K.
Reminds me of all the 409 v8 Chevy motors I repeatedly splattered
back in the late '60s if I went over 6K.
When the exhaust valve push-rod punched through the rocker arm,...It was instant death to the beast.
This 3.4 has six separate carburetors. Each carburetor looks similar to the two carburetors used on an adi fired 850-4.
They are most definitely a bit bigger than the ones on an 850-4.
It is beyond running (3) 850-4 Mercs at the same time off of one gas tank. Gas will ne gone before you know it.
I made contact with Nick @ Wintech, and he is going to do my driveshaft work.
I am attaching a few pixs of the dead 3.4 beast I bought to obtain the drive-shaft for my 20" 3.4 L/U.
When you see the carnage caused to the one cylinder/piston,...You really have to respect the design of the beast that isolates that one cylinder from the others and allows the beast to get you to shore on the remaining (5) cylinders. Look carefully at just how ripped the connecting rod is. What a beast!!!
The rod looks really similar to a rod that let loose in my '71 LT-1 350 SBC that was 'worked' and turned 8600 RPMs in all four gears in the 1/4 mile at 10.3 with an M-22, and a 5.38:1, in front of a welded 12 bolt.
One picture shows a 1500 inline-6 piston placed in a 3.4 v6 cylinder. (99.9 cubic inches-vs-205 cubic inches) maybe it is 207 ci???
Definitely a piece of Mercury history, but not one to push the limits on.
Yes Scott,...Way too much Folgers, but now they are used to house masses of sorted Mercury goodies, and nuts & bolts.
The Cosworth Carnage pictures are of a '92 3.4v6 I picked up cheap for the driveshaft.
The '83 3.4v6 on my latest addition to my fleet starts and runs fine.
I finished reassembling the lower unit with a nice 20" shaft, and plan to put it back on the beast in the next couple days.
I still have to purge the fuel tanks, and dry out the upholstery, but that's about it.
I used my secret squirrel hydraulic steering bleed system to get rid of the air in the system.
I don't have plans to launch it until spring when the weather isn't so cold.