has anybody done the lifter valley mod shown at http://www.buickperformance.com/455LV.htm? reroutes returning oil so that instead of dripping down to the pan from the lifter valley, the valley is closed off and oil is routed directly to the pan via hoses down the back of the block. supposed to be good for 20hp for big blocks info taken from web page: Here are some of the benefits to strengthening the lifter valley in 400-430-455 Buick engines: 1. Strengthens the block: The Buick lifter valley is an open web design which is very weak and contributes quite a bit to block flex under load. By sealing and reinforcing the lifter valley, flex is greatly reduced and the block is noticeably more solid. This will significantly reinforce the lifter bores which will help prevent damage when using a big roller cam. 2. Reduce oil aeration: The open web design allows all of the oil from the top end to be drained directly over the cam and crank which are spinning (hopefully) at a high rpm. This whips the oil into a froth even before it is returned to the pan where the spinning crank continues to beat the hell out of it. After this it is picked up and returned through the block with a lot of air mixed in. By sealing the lifter valley and draining the oil externally to the pan, a good bit of this monkey motion is eliminated and aeration is kept to a minimum. 3. Frees up HP: As oil drains back over the cam and crank, the oil creates drag and draws quite a bit of HP. Bob Gilleland, Performance Concepts, claims he has verified a 32 hp increase on a Stg 3 7500 rpm engine. In my application, my Stg 1 that shifts at 6200 rpm, the ET slips say I picked up a solid 20 hp.
I wonder how this type of mod would work on the rover/215 aluminum blocks? I think they have similar hp losses due to oil drainage. Assuming an aluminum laced epoxy is available it might be worth a try.
when i searched the 455 forum for "lifter valley" it came up with about 7-8 hits that had some great info. it seems that the consensus is that unless you are running a race motor the mod is really un-necessary. there wasn't enough block shift to warrant the mods, and there were also concerns voiced about possible oil return blockages causing oil starvation. also cam oiling was a concern found a pic of someone who had done it in a search of the 455 section, it looked nice
