Do they need to be matched with a 73 and up crank?? I currently have a 72 crank with 72 rods. I plan on adding the 73 rods with high comp forged pistons, different cam, ported heads etc. Are the cranks the same?? 72 or 73 up?? At what point do I need to really worry about things weighing more or less than stock weight?? The piston / rod assy that I plan to install weighs 1355 grams and a stock assy weighs 1325 grams both minus bearings and rings. Do I need to worry about trying to rebalance the crank? Is there a place on the pistons I can remove weight that doesn't matter??
parts are interchangable. if your not racing the 350, i wouldnt worry about the weight difference. if your going racing, then changes are required. if my memory is right, our current setup weighs around 900 grams. but then again we turn over 6500-7500 rpms.
So the 73 and up 350 rods look totally different sounds like you've got the capscrew rods from a newer motor. they should be stronger than the original rods.
Yes.. They appear to be way stronger.. The TT car has the old style rods with the 12 pt nuts.. So far... So good.
In another thread you asked: I responded with: Here is how my machine shop did the ballancing on my engine.... http://www.popularhotrodding.com/en...ardcore/0412em_rotating_assembly/ind ex.html This pic shows the fixture to weight the ends. http://www.popularhotrodding.com/en...rdcore/0412em_rotating_assembly/photo_14.html The 68-72 rods are weak, they break where the rod broaches for the big end. for a stock engine they are fine although anything more than that go the with the 73-80 rods. ARP bolts are available for the late model rods. This combo is safe untill about 500 HP or really high RPM, above that step up to the Custom. OR spend BIG time and cash on the stockers. With the right prep the late rods can handle some good power. If you go that route read this: "The rods should be cap screw style. They should be polished along the side-beams to a mirrior finish, including, if not especially where the rod broaches at the point where it meets the crank. Have them sonic tested and magnafluxed and checked for size and straightness before you start. Grind all casting flash and all rough edges smooth. DO NOT remove any material from the bearing radius, or you could open up too much end play. Grind the ballancing pads down as much as possible [leave a little], and THEN have them rebuilt. Big end resized, small end bronze bushed for floating pins [only if your TRW slugs accept floating pins]. After you get them back, your still not done. Now it's time to ballance them. You can do this at home. GET THEM PERFECT, and matched to the pistons!!! You can also have them: Ion nitrited Hard chromed Directionally magnatized Chryogenically relaxed ..... The list goes on, just pick what looks best to you, and what your budget allows, and have it done" Makes me want to go and get the custom rods and just be done with it.....SO I DID! http://www.buickperformancegroup.com...orged+350+rods
http://www.v8buick.com/showpost.php?p=1334967&postcount=5 The copied/pasted URL's are broken because they were parsed in the original post. Devon
The info came from Daryl R. who was one of the pioneer Buick 350 builders. Pages 7 and 8 are where the quotes came from... The other info I shared with you is from a PM and from phone calls with him... More info in my book! http://www.v8buick.com/showthread.php?t=40660&highlight=350+article He found out the hard way what the limits were on the 73-80 rods and that was with all the tricks... TONS of time into them, ARP bolts and they broke on the dyno around 600 hp. When the 550+ hp NA Buick 350 made Buick headlines someone came up with an old single plane intake and sent it for dyno testing on the engine. Daryl was the guy who made the intake WAY back....
There are some pics of nicely lightened stock rods in this thread.... I have done the same to stock rods although I even smoothed and pollished the insides. I keep them for spares now that I have the forged rods. You have to scroll way over to the right to see all the pics: http://www.v8buick.com/showthread.php?t=197839&page=2
