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Engine basics => Engine set up tips => Topic started by: Bill Hummel on April 04, 2012, 09:14:14 AM

Title: head bolts for 40 VF?
Post by: Bill Hummel on April 04, 2012, 09:14:14 AM: Can one of you VF guys tell me what size head bolts go in the 40 VF? Thanks...
Title: Re: head bolts for 40 VF?
Post by: RandySmith on April 04, 2012, 12:59:14 PM: Quote from: Bill Hummel on April 04, 2012, 09:14:14 AM
Can one of you VF guys tell me what size head bolts go in the 40 VF? Thanks...

3mm x 12
Title: Re: head bolts for 40 VF?
Post by: Bill Hummel on April 04, 2012, 01:19:14 PM: Thanks, Randy...should've asked you when we were on the phone!
Title: Re: head bolts for 40 VF?
Post by: Howard Rush on April 04, 2012, 01:23:50 PM: Funny I didn't know that, but now that I think about it, I realize that I never needed to unscrew one.
Title: Re: head bolts for 40 VF?
Post by: Bill Little on April 05, 2012, 01:22:52 PM: Quote from: Howard Rush on April 04, 2012, 01:23:50 PM
Funny I didn't know that, but now that I think about it, I realize that I never needed to unscrew one.

I know what you're sayin' Howard. I freaked out totally when my OS .40VF lost all its compression one day. Flew fine, then next flight, zero. I blew out a glow plug insulator.......... never had that happen before.

Bill
Title: Re: head bolts for 40 VF?
Post by: RandySmith on April 05, 2012, 03:25:38 PM: Quote from: Howard Rush on April 04, 2012, 01:23:50 PM
Funny I didn't know that, but now that I think about it, I realize that I never needed to unscrew one.

I on the other hand have HAD to take over 200 of the VFs apart. Over a dozen of the 40s had bad liners, some people treat them badly..

Randy
Title: Re: head bolts for 40 VF?
Post by: John Leidle on April 08, 2012, 05:17:21 PM: Randy, Wat do the guys do to ruin the VF liners? Run them lean or suck in dirt? Paul Walker told me he had well over 1000 flights on his VF.
John
Title: Re: head bolts for 40 VF?
Post by: Brett Buck on April 08, 2012, 05:21:20 PM: Quote from: John Leidle on April 08, 2012, 05:17:21 PM
Randy, Wat do the guys do to ruin the VF liners? Run them lean or suck in dirt? Paul Walker told me he had well over 1000 flights on his VF.
John

Mine has more than that by a long shot. They don't wear out in normal service for many many years.

Brett
Title: Re: head bolts for 40 VF?
Post by: RandySmith on April 08, 2012, 05:56:07 PM: Quote from: John Leidle on April 08, 2012, 05:17:21 PM
Randy, Wat do the guys do to ruin the VF liners? Run them lean or suck in dirt? Paul Walker told me he had well over 1000 flights on his VF.
John

Run them hot ,lean and the liners suffer and many times peel
Run them with low oil, like the 14 to 15 % that many sport fuels contain and they will many times peel.
I see this most in VFs that have been abused , ran lean, wrong fuel, etc.
Its not only VFs I have seen the same in LAs, FPs, SFs, etc, this happens most in RC flyers planes, as Henry and Dave replaced many hunderds more than I did.
They also do not take well to racing applications.
I have replaced about a hundred with Chrome liners both VF and SFs engines
Run them rich or slightly rich and use decent fuel in your C/L plane and you won't have problems, or they will be few.
Dirt is also very bad on the liners, as it is most, it is best to keep whatever your flying clean and run an air filter

Randy

Randy
Title: Re: head bolts for 40 VF?
Post by: Randy Powell on April 08, 2012, 09:09:54 PM: Hitting the pavement with one doesn't help either.