Just talking about VWs

Discussion in 'Volkswagen' started by Pops, Mar 12, 2018.

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  1. Jul 9, 2018 #61

    wanttobuild

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    I ain't knocking you Pops by any means, but this ain't the past.
    Please don't take that the wrong way, OK?
    I will call Isky and post what they say.
    You know you gotta take the cht problems with the belt and suspenders approach.
    You may also know that Mark Langford is not just a Corvair guy, but also a VW guy.
    Take a look at his head choice and how he got there.
    I think I will ask for max power at 2900rpm.
    They are in California, gonna call back this afternoon, also gonna nitride the lobes.
    Ben
     
    Last edited: Jul 9, 2018
  2. Jul 9, 2018 #62

    Pops

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    May not be the past but physics doesn't change. Isky will base everything on high rpm torque because that is their market. Try MAX Torque at 2700 rpm for a more efficient prop.
     
  3. Jul 9, 2018 #63

    wanttobuild

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    Ok, Pops.
    Will post what they say.
    Ben
     
  4. Jul 9, 2018 #64

    Vigilant1

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    Ben,
    Just so I understand--what are you trying to accomplish with a custom cam? More HP at lower RPM? At 75-80HP (regardless of RPM), we are already right at the limit of the ability of the stock heads to shed the generated heat from combustion using conventional methods (a good plenum, enough fins, etc). Above that requires running rich, evap cooling, water injection, liquid-cooled heads, or some other esoteric magic. So I'm guessing you are trying to get that same 75-80 HP at 2700 RPM?
     
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  5. Jul 9, 2018 #65

    wanttobuild

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    Well I want a 2176 turning 2700rpm making 70hp with a cht of 275-300deg.
    I am still not convinced that the heads won't shead enough heat to be within a reasonable temp.
    Many things come into play here.
    I believe ignition timing, lift and duration play a part.
    I have finally found the plane I'm gonna build and it's gonna be vw powered.
    Ben
     
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  6. Jul 9, 2018 #66

    wanttobuild

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    Hey Pops
    Hydraulic or Solid lifters?
    Ben
     
  7. Jul 9, 2018 #67

    Vigilant1

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    Gotcha. Per the dyno graph below (from a 2176 Aerovee with the stock Aero"injector" carb), an engine setup for max HP at 3400 RPM can be expected to give 65 HP at 2700 RPM, so what you want seems to be within reach, and might be achievable with EFI and EI alone. 70 HP at 275deg F CHT may depend entirely on your baffling/attention to details. It probably won't happen if the jugs are just out in the breeze.

    HP-Torque_graph.jpg
     
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  8. Jul 9, 2018 #68

    wanttobuild

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    If Isky acts snotty, I'll call Crane.
    It ain't like the old days, they will grind what you want.
    I'm gonna tell em that I am putting a vw engine on a Hobycat! Lol
    Ben
     
    Last edited: Jul 9, 2018
  9. Jul 9, 2018 #69

    Pops

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    Solid lifters, Hydraulic lifter can mask an earlier problem. I change oil at 25 hrs and while I'm changing oil , that a couple extra minutes and check the valve lash and record to check for a trend. If there is a problem, I want to catch it early.
     
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  10. Jul 9, 2018 #70

    Pops

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    And if you use the Revmaster Heads that have a little better cooling than other heads to take care of the extra heat.

    I need to get back and finish my flywheel drive, 2180 cc, VW engine using single port heads and Zenith carb with 1 3/8" dia intakes , non-electric with a mag drive on the pulley end swing a Culver 62"x 26" wood prop for a somewhat draggy SSSC. Saving every ounce I can.

    I think the chart is little on the optimistic side.
     
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  11. Jul 9, 2018 #71

    Pops

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    Friend of mine used to have a Sky Raider with a 60 HP HKS engine. (Geared engine). The Sky Raider had an EW of 485 lbs, my SSSC EW-485 Lbs, Same size wing. They had the same ROC and the same top speed. He weighs 170 lb and I weigh 230 lbs. Same amount of fuel . So, my 1835 cc, VW engine must be producing very close to 60 HP. At 2650 RPM cruise the 1835 cc VW engine is burning almost 3 gph, so that is about 33-34 HP at cruise of 80 mph with a 60"x 26" Culver Prop. WOT of 3100 rpm = 1200+ ROC. Zero heating problems, runs to cool below 70 degs OAT, I unhook some of the air to the oil cooler.
     
  12. Jul 10, 2018 #72

    wanttobuild

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    Isky wanted to know what year the engine was. Scratch Isky. Going with Engle. They know what they are talking about.
    Ben
     
  13. Jul 10, 2018 #73

    wanttobuild

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    I like your engine Pops. For my need it would be perfect.
    But single port heads are scarce as hens teeth!
    I just want to try and run a large stroker at a low rpm.
    It would be great if someone, maybe me would start a list for everything to make up your engine for the sssc.
    That way you could just sit down with your card and start ordering. No thinking, just spending.
    Trying to gleen info is time consuming and you may not get it right.
    There is a lot of interest, just look at the number of views on this thread.
    The cht problem has got to be resolved!
    I'm gonna try, but may fail. It's been known to happen.
    If I could quote Dr. Langford (Mark), I'm kinda funny about my heads cracking between the seats.
    OBTW, look at the Revmaster automotive site.
    The 049 heads.Those 1/8 mile boys go.
    I am a big fan of fuel injection, and crank triggered electronic ignition. It will effect cht and egt.

    You know you have to have a cut, not ground 3 angle valve job, first to seal then to shead heat.
    I would be willing to bet most engines have not been assembled with the attention to detail that is so important, I won't say critical because most will still run, but run hot.
    There are many other factors, but those factors are what is leading me to believe the heads are ok.
    Just the assembler and the operator.
    Ben
     
    Last edited: Jul 10, 2018
  14. Jul 10, 2018 #74

    fly2kads

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    I ran these single port heads on my last Beetle, and was pretty happy with them.
    http://vwparts.aircooled.net/Single-Port-Cylinder-Heads-COMPLETE-15-1600-p/sp-cylinder-heads-pr.htm
    They also sell them with a valve job and some mild porting for a little more $$.

    I like the idea of a larger displacement motor running at lower RPM. I have occasional thoughts about putting one together.

    Pop's right, the stock cam does pretty well at lower RPMs. I think a custom cam might be worth checking into, though. The prices are reasonable since the blank they're starting from is readily available.
     
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  15. Jul 10, 2018 #75

    Pops

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    First-- You can buy new single port heads. https://aapistons.com/collections/c...-of-stock-head-single-port-w-seats-and-guides
    Other places also carry the single port heads. For a while the single port heads were not being made but not now. Will have to have them bored for the oversize pistons and jugs that you will be using , same for the case.
    When you get a head, inspect the air passage holes in the heads for flashing and clean smooth with drills, round files, etc. You would be surprised the amount of passages that are plugged up.
    For proper cooling the valve seat and valve has to be seated to a certain width for proper heat transfer from the valve to the heads.
    I use 7.5 to 1 compression ratio for EVERY Cylinder. So each head chamber has to be CC'ed, deck height measured, etc, etc.
    I balance the pistons to within 1 gram
    I balance the total weight of each rod to 1 gram and also balance each end of the rods to 1 gram.
    Single port heads do not have the problem with cracking between the spark plug threads and valve seat area like dual port heads.
    Use the Zenith carb for the size of engine you are building from Great Plains. Will have to make your own intakes for the single port heads since everyone is using the larger dia dual port heads. Intakes -- 1 1/4" dia for up to 1835 cc, 1 3/8" dia for 2180 cc engine, do not use 1.5" dia intake dia tubes. Will get lower torque at the lower RPM's because of lower intake charge velocity. IF cruising over 3K rpm, then use the 1.5" dia intakes.
    Yes, build for low rpm torque.
    One of the best mods I did that gave me more power and a smoother running engine and stopped the carb ice in a NY heartbeat problem was the hot oil box at the base of the intake at the carb flange. Still use the exhaust manifold carb heat for extra insurance as normal usage in a small cont engine.

    I get all of my VW engine machining done at Keith's Auto Parts , VW Specialists since 1970 when I built my first VW engine. VW's is all they do. At one time they had the world's record holding VW dragster. The do mail order. Call and ask for Vick at 1-800-RACE-A-VW. I have nothing in the business, just friends for many years. 100% happy with all of their work for all of the years. Prices are also good. Vicks father, Keith was my age and Vick was 10 years old playing with VW's when I first went there for engine work. Good people.
     
    Last edited: Jul 10, 2018
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  16. Jul 10, 2018 #76

    wanttobuild

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    Single port heads ain't gonna cut it for the engine I envision. Its gotta pump a lot of air. Low rpm and large amount of air/fuel flow.
    I'm hung up on the valve seats right now. And I like solid brass valve guides. No silicone.
    Ben
     
  17. Jul 10, 2018 #77

    Pops

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    That is why at the low RPM's you want the higher velocity intake charge. At the lower RPM's you will lose power with the dual port heads.
     
  18. Jul 10, 2018 #78

    FritzW

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    I haven't caught up with the whole thread, so sorry if this is off topic:

    I picked up a HAPI (Mosler) VW this weekend. It came off my chapter buddie's Dragonfly that's being rebuilt to carry a Rotax 914. I don't know a thing about it but I liked what the data plate said. IF I can get it to fit on the Neirrh I'm going to give it a try.


    20180709_205722_resized.jpg 300 total time (but, probably, still needs a rebuild)


    20180709_205743_resized.jpg I've read good and bad about Mosler heads but it's worth a try


    20180709_210113_resized.jpg The numbers (if true) are better than the GPAS 1835 I've got sitting on the bench

    P.S. the engine serial number (555) is the same as my EAA chapter number so I think it was meant to be... :roll:
     
  19. Jul 10, 2018 #79

    wanttobuild

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    I guess the thing to do is find the best quality weldable alloy head you can find, cut off all the fins, getting it down to just the head.
    Then purpose build cooling fins out of flat sheet aluminum. Clean sheet so to speak.
    Pops, the loss of power at low rpm is exactly the reason I am visiting the cam. I know OT10 has always been the go to, but I don't think this has been looked at for a while now.
    Thank you for all the info provided, and in the end at least I know I will have an engine I can copy that WORKS.
    I will talk to the folks at Engle today.
    I will post what they have to say.
    Ben
    H-Minus
     
  20. Jul 10, 2018 #80

    Kyle Boatright

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    I'd extend the fins that came with the head, rather than chopping them off. I wouldn't want to weld on the head itself.
     

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