

| Subject: | Re: Lifter/Valve question |
| From: | Bob Donalds |
| Date: | Thu, 4 May 2000 12:41:56 -0400 |
> > Bulley wrote: > > > > Bob- > > > > As always, I value your guidance. > > > > My 1982 Westfalia 2.0 liter with 96mm jugs/CW crank is due for what I > > consider a "normal" service, but I thought I'd check my experience with > > yours. > > > > I have found that 5-7k after an air-cooled rebuild, it is helpful/necessary > > to re-torque the lower head bolts, re-adjust the valves (even if hyd), and > > snug up the exhaust manifold nuts. I'm planning on doing this service on > > Saturday a.m. (since there is no VW mechanic here). > > My questions: > > 1. Have you found the need for head re-torque/valve adjust/exhaust > > re-torque to be true? Am I just carrying mental baggage from my days > > building type 1s? (we used to re-torque lower head bolts at 5k, then every > > > > > > Thanks, > > > > G. Matthew Bulley > > > Matt > glad your back on the list I have missed your input and wit > re-torqueing heads bolts is a time honored tradition with the air cooled > engines. > As you may know I rebuild single port engines for use in zambonis (ice > rink resurfacing machines.) Air cooled enignes in this application live > a very hard life that was measured in months not years until I made some > simple changes. these poor little abused engines had all the symtoms of > the its street counter part but in a tenth of the time pulled head studs > burnt valves cracked heads. When I lowered the compression ratio to 7 > from 1 from 7.75 to 1 the life of these engines increased to the point > that I was putting my self out of the zamboni engine business. I now > offer a 2 year warrenty on all my air cooled industrial engines. I keep > in touch with the techs that maintain these these engines. As a part of > tuning they retorque the lower heads nuts before they adjust the valves. > They report to me that some engines don't loose there torque. One of > these engines is local and I have stopped in and measured the oil temps > after it makes ice. this engine runs at 185 oil temp and its propane > fueled but thats another story. The point In am trying to make by > telling you this story is that when the engine is within a reasonable > oil-head temp range it makes better power, lives longer and it heads > nuts are not as likley to loose there torque. I do use the fuelie bug > blocks on the propane engines they are made of the same stuff the air > cooled vanagon blocks are made of. The bottom line is if the head nuts > loose there torque the engine is getting to hot. > > Gene Berg was right! he said to me more than once what do I have to > gain by telling you to run lower compression ratios. he gained my trust > and loyalty. > > . When you adjust type 2 valves how many turns do you give? (I'm a one > > turn guy, but I know some say 'no clearance' some say '2 turns', or 5/8s > > turn, etc.) > > > Just preloading valves a turn or two would be a mistake some hydraulic > lifters cant take much of a preload ever I dont know why. This has > become a huge problem for the air cooled vans and I have seen it in the > watercooled also. Burnt valves in a very short time is not uncommon even > with the good seats and valves. The valves must touch the seats to > disapate the heat or they fail. > To prevent burnt valves I now tell my customers that they need to do a > compression test before and after the engine has had the the lifters > preloaded and they preload the lifters at there own risk! I have backed > off my customers preloaded valve adjustment with gains of 20 pounds > across the board when they just preloaded and did no testing. There has > been no report of lifters failng because of valve adjuster > lash(clearance) my own van has run this way for 2 years. Its not clear > why this is happening but I have personaly backed off the adjusters for > the editor of the vanagon manual and cured his low vacuum,poor > performance and low compression readings in his own air cooled vanagon. > > 3. How frequently should I adjust my hydraulic valves (ever?). > > > It may take more than once to get the valves there they need to be or at > least as close you can get to preload. A compression test needs to be > apart of any valve adjustment. once the the valves are set and checked > for full closing your done with adjusting. > > My man at Bentley says > (Bentley gets its info from VW and passes it along without > passing jugdement they have told me they do not feel free to modify > that's been handed to them without a tech bulletin to back it up even > when I have proven to them that there is a better way. I did ask them to > include my web page address in the next vanagon book but they declined > go figure. > > I am looking for fuelie bug blocks if anybody has one or more to sell > > hope this helps I must get back to work assemble yet another 2.1 long > block > Bob Donalds > http://www.bostonengine.com
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