FAQ 115
Question: I recently purchased a 1776 performance engine from Mofoco with hydraulic lifters and 1.25 scat rockers. I've got about 900 miles on the engine and have had to adjust the rockers 2 times now to keep them quiet. Mofoco told me to adjust them 1 1/2 turns past zero clearance and that should quiet them. Well I have done that but the lifters on cylinders 1 & 2 keep making noise after I run it for a day or so. Is there something else I should try like different weight oil? I am now using 10/30 weight oil and my oil pressure is around 20lbs at idle and 30lbs cruising. What do you think? Bill Answer: Below is my reply, and a later response from Bill. Thanks Bill! -- Bill, I'm not an expert in hydraulic lifters. I seem to recollect that when I did the head on my '64 Mustang, the lifters took an hour or two of running to pump up. However, I think I forgot to bleed the lifters before installing, which meant that I ended up tightening and loosing the lifters several times. Once, I did it with the engine running, and that was a huge mess. It may make more sense to back the adjusters off to about .006 clearance, and let the engine idle a bit in the hopes that the lifters will pump up. Let the engine cool and then adjust as normal. The Bus shop manual says that VW lifters should be bled (filled with oil) prior to installing in the engine. They recommend 2 turns after the adjusting nut contacts the pushrod. Engine must be cold. You might ask Mofoco if they remembered to bleed the lifters before assembling the engine. How much did your engine cost? What is your idle oil pressure? 10W-30 oil should be fine. I'd love to hear how this turns out for you. I want hydraulic lifters in my next engine since a lot of the engine noise seems to be from the valve train. Best of luck, Tom. -- Bill's reply: Good Morning Tom, First, I want to thank you for returning my email. I have been a mechanic all my life but I still like opinions from others when I face problems. Most Websites I email are very impersonal when I have asked a question. You answer is very helpful. This last weekend I spent most of it working on my bug. I found a rocker on cylinder #2 loose again so I just adjusted down once more. I asked a local VW vendor, Pozzi's, here in Sacramento about the lifters and he told me he preferred solids and hadn't had much luck keeping hydraulics quiet. I have had hydraulics in all my previous cars and have always had luck with them. So far, since I readjusted these they are quiet. I drove to work this morning on the freeway and all the valves were quiet. I agree with you that it is real nice to have a quiet valve train and I will not give up on hydraulics. I also thought I'd tell you that this engine really runs nice. I changed over to dual Kadrons this weekend from a single 2 bbl. Holley Bug spray and man what a difference. No more Holley stumble, Ha!, and no more single carbs for me. I didn't want to spend the big money for the Webers so I bought the Kadrons and found them very easy to sync and set up. I was told that these carbs are very good on the gas also. I will keep you informed on my hydraulics and do recommend them. Oh, you did ask me about the oil pressure and I have a high output pump in this engine although Mofoco didn't tell me what type is in it. I run about 20-25 pounds at idle, after warm, and about 30 - 35lbs on the freeway with a HP-1 Fram filter. The engine is the Mofoco Streetwise engine they advertise all the time. I had them add the 1.25 Scat lifters with solid rocker shafts, Perfect seal rings, case taped for full flow oil and mounted an external filter, and am running a 050 Bosch distributor. The basic engine without the extras was $1699.00. The extra's cost me another $300.00. Runs great! Thanks again for your answer. Bill -- As a postscript, in a later note, Bill again says that he is happy with his Mofoco engine, but found that support was less than he'd like after the sale. He says that he thinks he would try to buy and engine locally before going with Mofoco again.
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