bizjetmech
Active Member
Putting together my 340 (finally). Got the rods/pistons in and torqued. Everything is looking real good on this thing, except the rod side clearance on the 3-4 and 5-6 rods are too much.....book sez .014 or thereabouts, on these two pair of rods, it's more like .020. Big deal or no? I'm inclined to think I can maybe get away with it, since all my rod clearances are not on the crazy-loose side.
(Forged crank 340, stock rods, hydraulic cam, no mods to block, Milodon HV pump)
I have a set of used 340 rods that I can mike and find the widest pair/set to improve this, but I'd have to send them to the machine shop for resizing, ARP hardware and rebalancing......which means a couple of weeks before I can continue building this beast.
-Compression ratio is working out to around 9.6-1. Trying to decide on the cam. One is a 230 @ .050/.480 lift (brand new). The other is the cam that was in the motor when I bought it, can't tell for sure, but it appears that it is the .509 lift hydraulic "Purple Shaft". Normally, I wouldn't reuse it, but it has the advantage of already being broken in, and figured I can always put the other cam in later, after engine break in, and if the .509 is too radical.
(Car is Duster, street car, 3.23 gears, 727 with aftermarket 11" converter, approx-300-400 RPM higher stall than stock. Plan is "stock appearing + TTI headers, but running a lot better than "stock").
-Have an old Weiand 7507 dual plane that I was planning on using (came with the engine). Mainly for "stock appearance" reasons, if you know what I'm getting at. Is anyone still doing the old "mill away the plenum divider" trick us geezers used back in the 70's, or did they improve the dual planes enough by 1990 that this isn't recommended?
(Forged crank 340, stock rods, hydraulic cam, no mods to block, Milodon HV pump)
I have a set of used 340 rods that I can mike and find the widest pair/set to improve this, but I'd have to send them to the machine shop for resizing, ARP hardware and rebalancing......which means a couple of weeks before I can continue building this beast.
-Compression ratio is working out to around 9.6-1. Trying to decide on the cam. One is a 230 @ .050/.480 lift (brand new). The other is the cam that was in the motor when I bought it, can't tell for sure, but it appears that it is the .509 lift hydraulic "Purple Shaft". Normally, I wouldn't reuse it, but it has the advantage of already being broken in, and figured I can always put the other cam in later, after engine break in, and if the .509 is too radical.
(Car is Duster, street car, 3.23 gears, 727 with aftermarket 11" converter, approx-300-400 RPM higher stall than stock. Plan is "stock appearing + TTI headers, but running a lot better than "stock").
-Have an old Weiand 7507 dual plane that I was planning on using (came with the engine). Mainly for "stock appearance" reasons, if you know what I'm getting at. Is anyone still doing the old "mill away the plenum divider" trick us geezers used back in the 70's, or did they improve the dual planes enough by 1990 that this isn't recommended?
