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VW Heads Designed for Aircraft- Poll

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Value of purpose built VW aircraft heads

  • Why bother. Who would try to use '30's auto technology to fly.

    Votes: 1 4.2%
  • It's an interesting idea but what we have now is good enough.

    Votes: 2 8.3%
  • If they were close in cost AND better I'd probably use them

    Votes: 11 45.8%
  • It's been needed for a long time. They will make the VW a far better option.

    Votes: 10 41.7%
  • It would be the best thing to happen to EABs in the last 2 decades

    Votes: 0 0.0%
  • Why bother. Who would try to use '30's auto technology to fly.

    Votes: 1 4.2%
  • It's an interesting idea but what we have now is good enough.

    Votes: 2 8.3%
  • If they were close in cost AND better I'd probably use them

    Votes: 11 45.8%
  • It's been needed for a long time. They will make the VW a far better option.

    Votes: 10 41.7%
  • It would be the best thing to happen to EABs in the last 2 decades

    Votes: 0 0.0%

  • Total voters
    24
  • Poll closed .

stanislavz

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It has been mentioned a few times, I brought it up in one of my first posts on HBA. I'll just say there was no applause. In theory it would be a good way to move heat from the exhaust side of the head to "somewhere else" (?) where it can be disposed of, but the practical considerations of doing that are significant.
It may be. It all count on details. If you could take stock air cooled head, mill it and attach to custom made cover - it may work. But it will add few kg more.

But - on this side of globe - it is way cheaper to buy used rotax912, check it, make all dimensions etc. And you know what you have. I have similar dilemma for myself - but if you do not have vw motor / bmw boxer or suzukis on hands - you are spending at least 1k on bare used engine, which you will have to tear apart and rebuilt. + gear box / prop adapter. And no-one will give you any warranty.
 

Hot Wings

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But, IMO, asking for significant additional continuous HP because we have more head cooling will just invite other problems and ill-placed gripes about the reliability/suitability of the base VW design for aircraft use. That's happened in the past.
Agree. That is just human nature. Give us some margin and we will use it up - and then some. Solve the new problem, rinse/repeat.
Depending on how you figure the generations we are on VW Aero G3 at the moment, maybe G4.
 

Bill Volcko

Member
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Mar 1, 2020
Messages
5
I am running an Aerovee 2.1 with Empi heads. Exhaust valve seats needed regrinding after 30 hrs. Who makes better heads?
 

Hot Wings

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Exhaust valve seats needed regrinding after 30 hrs.
<< >>
Who makes better heads?
That is an unusually short time, even for poor quality seats. I'd be looking for other problems, like improperly adjusted valves, or poor cooling shrouds.
<< >>
IMHO your best option is to stick with what is offered by the big 3 VW conversion suppliers. Second is find a local VW builder with the proper tools and knowledge/experience. They may know the current state of the market. I've been away from this on a day to day basis far too long to know who is a quality supplier.
 

Bill-Higdon

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Feb 6, 2011
Messages
813
Location
Salem, Oregon, USA
I am running an Aerovee 2.1 with Empi heads. Exhaust valve seats needed regrinding after 30 hrs. Who makes better heads?
I know of a couple of VW conversions in my neck of the woods, they're all getting over 30 hrs before needing attention to the valves, something else is going on here IMHO
 

Vigilant1

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I am running an Aerovee 2.1 with Empi heads. Exhaust valve seats needed regrinding after 30 hrs. Who makes better heads?
That is disconcerting, as I have some hope that the Empi heads might work well (they looked promising and I'd heard the air passages were largely free of flash, which is a big deal). Did you get yours from Aeroconversions/Sonex? Like Hot Wings, the very short time in service would make me wonder about possible problems with valve adjustment first. A little too much gap is much better than too little.
 

Bill Volcko

Member
Joined
Mar 1, 2020
Messages
5
That is disconcerting, as I have some hope that the Empi heads might work well (they looked promising and I'd heard the air passages were largely free of flash, which is a big deal). Did you get yours from Aeroconversions/Sonex? Like Hot Wings, the very short time in service would make me wonder about possible problems with valve adjustment first. A little too much gap is much better than too little.
Lash was adjusted 4 times in the 30 hrs of operation. Valves were fine....seats warped.
 

Hot Wings

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Steel of some sort.
That doesn't narrow it down much. ;)
TFF's suggestion is actually a fairly good one. Find someone that can replace the seats with ones of known quality and material. If the cooling system has problems this could be an expensive experiment.

I've seen seats in "good heads" that cut like they were made of wrought iron and left a grainy surface under my Neway cutters. Genuine VW heads had seats that cut smoothly, and left a nice shinny surface that didn't need any lapping to seal. Some aftermarket heads had equal or better seats.

Seat material has changed/advanced a lot in the last 20 years. There are even better materials than those that were once considered 'the best'.
 

Vigilant1

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This case may exemplify one challenge of operating a VW Type 1 (and I've been through this myself). Parts, including heads, are inexpensive enough (by aircraft standards) that it is hard to justify paying much money for a "maybe this will work" fix. If a person doesn't feel comfortable diagnosing the problem and fixing it himself (hours, new tools, uncertain results since "right" can be very hard to judge from a book or video), then he has to find a VW pro (and they are getting less common). When all is done, maybe it still won't work (it wasn't the valve seats after all, or maybe now the head is warped, etc). It doesn't take long to spend more than the price of new parts. It looks pretty good to just buy a new, shiny head put together by folks who presumably know what they were doing. Get a reputable brand and it should give good service for a long time, which is a lot better than making a crummy part limp along for 30 hours at a time. Or, such is the hope.
I can sympathize/understand why the question was "who makes good heads' rather than " what went wrong and how can I fix my head(s)?".
I'd first look around and see if the Empi heads are failing for other folks.
FWIW, I have Mofoco heads on my "Aerovee-GPAS" hybrid engine. I'll look for something else next time.
 
Last edited:

Armilite

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Sep 5, 2011
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AMES, IA USA
I am running an Aerovee 2.1 with Empi heads. Exhaust valve seats needed regrinding after 30 hrs. Who makes better heads?
================

You running Unleaded Fuel in Heads Designed for Leaded Gas? You need Harden Steel Valve Seats Installed or run 100LL which has Lead in the Gas.
 

Methusala

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Sep 19, 2020
Messages
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Just found this thread this morning and, no, I haven't read it fully. Saw that, early in the pages it was suggested that Bosch Jetronic D was hard to run these days. I ran this hardware, including original injectors for 550hrs on a 2074cc conversion. Used a Haltech F9 programmable ECU and no problems. Ran 3600rpm for initial climb to 300ft then cruised on 3200. There was a 10k pot enabling adjustment of set mixture +/- 10%. Ran lean for initial climb then back to normal for cruise. Oil temp 42degc, Cht around 350 and EGT around 1100f from memory.
 
Last edited:

Vigilant1

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================

You running Unleaded Fuel in Heads Designed for Leaded Gas? You need Harden Steel Valve Seats Installed or run 100LL which has Lead in the Gas.
His Empi aftermarket heads are fine for use with unleaded fuel. According to this site, the original VW heads had hatdened valves and seats and if they were made in/after 1966 they can be used with unleaded fuel.
 
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