Fourtitude.com - Help me build my 1.6L EG Heron Motor
Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    Fourtitude.com


    Page 1 of 2 12 LastLast
    Results 1 to 25 of 34
    1. 10-17-2016 07:54 PM #1
      Goal: To build a "retro racer" type engine that is period-correct in terms of hardware but modernized in terms of fueling and control. Priorities are as follows:

      1. Period correct looks and parts (1.6L, 8V, normal manifold)
      2. High efficiency (high CR, low rotating mass, good fuel system)
      3. Modern technology (EFI, Crank ignition, Knock sensing, closed loop EGO control)
      4. High Torque (I know its tough without a displacement increase, but I like the peak powerband around 3000-6000)
      5. Sweet feel and sound (square/oversquare, nice power ramp up to about 7000)
      6. Under $5000 total engine build. And that's 5000 Canadian pesos...

      Me: This will be my first time building an engine from scratch, but I have done headwork and engine swaps before. I have access to machining and fabrication equipment. I am very good at custom fuel systems, megasquirt, and anything electronic/programmable.

      The car: My car is a 1980 VW Scirocco in excellent condition. It has a 1.6L EJ motor (83hp) with 160k and runs strong. It has a well supported chassis (bracing, suspension, brakes upgraded) but the powerplant is stock.

      Parts I want to use: I would like to use my OEM block. I have a NOS 1.6EG Heron head. I have a mk4 exhaust manifold and a downpipe to match, and a 2.25" custom exhaust already mounted.

      So, what I'm looking for is some advice on the following:

      - I have sourced some Heron-style pistons, 80.5mm, with a 11.6:1 CR, from Techtonics. They are reasonably priced. OR they can custom build whatever piston for around $750. Since I want to stay at 1.6L, and realize quite large power and efficiency gains, the 80.5mm pistons seem right to me. What do you guys think?

      - What else can be done to the Heron head to increase efficiency? What should I NOT waste my time with?

      - The head currently has a G-grind cam installed (OEM). I am considering the Autotech 286. I want good driveability and torque, and I want it to freaking scream when I ask it to. I would like to avoid having to machine valve cutouts into the pistons if I can get away with it, so I need something with not too much total lift.

      - 11.6:1 compression?. There is so much information out there on whether this CR is too high for pump gas. I plan to order an MLS head gasket from Cometic:

      http://www.cometic.com/ag-1343563-vw...97-8v-16v.html

      which are available in many thicknesses. Hopefully I can find a good combination which will net a decent CR and leave enough room for the valves with whatever cam I choose.

      How do modern engines get a way with CR's as high as 14:1? Is there anything else I can do to the head and/or pistons to handle the higher compression? Perhaps if I run a very high fuel pressure and special injectors? Special Atkinson cycle cam? Some suggestions I have read is to use a long duration cam so that the effective CR is lower. However, this goes against the goals of high midrange efficiency and torque. I want to keep the throttle opening high at cruise to boost efficiency. I'll probablly initially build the motor with the G-grind cam. Since the EG makes 105hp stock, 120 or so should not be unfeasable with other modifications. Are there any other cam options out there with a good balance of reasonable lift and duration that are better than the G cam?

      Hopefully we can have a discussion here, people don't seem to care much about small non-turbo engines anymore!

    2. Remove Advertisements

      Advertisements
       

    3. Member
      Join Date
      Nov 30th, 2011
      Location
      Adirondacks NY/Northern NJ
      Posts
      1,412
      Cars
      84 Rabbit Convertible, 88 Quantum Syncro Wagon, 88 Fox Wagon
      10-18-2016 04:29 PM #2
      It seems like you're pretty well sorted on what you want to achieve and what direction you want to go which is good, but what are you looking to get out of this engine in terms of horsepower and torque overall? I know you mentioned 120hp at the end of the post, but I'm just trying to get a feel if you're looking at trying to get more than that or not.

      I will answer a few things though

      1. 11.6:1 CR pistons will be ok for pump fuel if you are planning to go efi, which it seems like you are. I am at 11.7:1 CR in my very high strung 1.9l 16v and it normally runs on leaded 112 race fuel, but on occasion it seems pump 93 and does fine once I switch ignition maps, otherwise you can tell it doesn't like the pump fuel too much. Knock sensing or more importantly, the ability to fire the spark at the correct time is the key to running pump fuel with higher compression ratios.

      2. The G-grind cam vs the 286. I just helped my buddy build a 2.1l 8v and he is running a CATCAM 280 or 286 with a very well ported JH solid lifter head, I cannot remember which, but it is a super driveable camshaft, granted he's got a lot of displacement over you, but it's still very nice to drive. Much nicer than my 16v around town. The 8v head overall promotes better low speed swirl within the cylinder which will help create better lowspeed torque and horsepower than my 16v by nature. So even though my 16v produces 200hp at the wheels and doesn't hit the rev limiter until 8100 rpm, it doesn't start really making serious power and torque until over 4000 rpm where he is building it at like 2500 even with that big camshaft. So I think you could run the 286 with little issue, plus with the addition of an adjustable cam pulley you can adjust the powerband of the engine by advancing or retarding the camshaft.

      3. Piston size. I think really this is up to you. It all comes down to how close to that original bore you want it or how far the block has worn which is more of the deciding factor than anything. For instance when I was building my 16v I had a very special set of custom JE pistons made, but I had to wait to measure the actual bore of the block. I was dead set on using 81.5mm pistons, which is .5mm over stock for a 1.8L 16v. I ended up with 82.5mm pistons which I'm very pleased with. I'd measure the bore and go from there.

      4. Things you can do to help the engine run well with the higher compression. Really I feel that if you've done what you can to make sure the bottom end is solid in terms of tolerances and you're using good forged components and the head is well sorted you really just need to look no further than tuning.

      5. Things you can do to make the head more efficient. You already know, I'm sure, that porting and polishing will help a good deal especially with the cam. You could look into using a set of ITB's because they will flow better than the stock intake manifold (big expense though) and maybe a bigger header, but these are things that aren't really necessary if you're not trying to squeeze every last ounce of power out of this engine, they do help no doubt about that. If you did want to spend some extra money and go with some ITB's, Jeveny just released a new product called the DCOE Heritage throttle bodies. They look like Weber DCOE's but the fuel injectors are hidden in the fake bowl of what looks like a carburetor. This is a wicked cool option for a retro racer style engine because Weber DCOE's were the go to for these engines to make more power and still are in many cases today, so it looks like you chose to go with carburetors, when in fact you get all the benefits of modern EFI. Here are some pictures.


      Quote Originally Posted by tolusina View Post
      An approximate Tim Taylor quote; "If you didn't build it yourself, it's not really yours".
      Function is the form.
      1984 Rabbit Convertible
      1988 Quantum Syncro Wagon - The Group B Grocery Getter

    4. 10-19-2016 06:29 AM #3
      Those DCOEs look very nice.

      I presume you are talking about the Woessner 1.6 pistons? Horrible design actually. But, because the pistons sit so damn far down the bore at TDC, you won't need to cut valve pockets! But also have no squish, poor combustion shape, and probably too high compression for something without knock sensing. It will need a ton of ignition advance to make power. Do you have high octane fuel there?

      Heron pistons are a big compromise. Some people have used G60 pistons because they have the deep bowl, with the cylinder block milled down for correct squish, plus valve pockets machined.

      Be warned those 1.8 cometic gaskets may not be OK for a 1.6 block/head because the oil drain holes are different.

      You could go for simple flat top pistons and a nice chambered head if this is really for a race engine. Or if road, I'd stick to OEM 'EG' pistons and gasket etc. Otherwise you are just creating expensive problems for yourself.

    5. Remove Advertisements

      Advertisements
       

    6. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      10-23-2016 03:12 PM #4
      Chopperoli: Those are actually ITBs made to look like DCOE carbs.
      Anyway, I think 11.6:1 is too high for pump gas in an 8V. It may work with a larger cam to effectively lower compression and I would definitely use a knock sensor ignition.
      The head responds well to porting and larger valves but not needed for 120 HP. They were 110 stock, so 120 is pretty easy. If going EFI, 034 has the inserts to allow EFI injectors to be used.
      I have a extra new set of std bore pistons for use with a 1.7 crank. I have all the parts to build a 1.7 version and will build it eventually.

    7. 10-25-2016 01:37 PM #5
      Interesting, what are your 1.7 piston tops like? And what C/R? Are they Mahle?

    8. 10-25-2016 03:17 PM #6
      Quote Originally Posted by dougkehl View Post
      what are you looking to get out of this engine in terms of horsepower and torque overall? I know you mentioned 120hp at the end of the post, but I'm just trying to get a feel if you're looking at trying to get more than that or not.
      Maybe I'm alone on this one but I find the car an absolute blast to drive with the entire 75-80hp it has right now. I love tight twisty roads where top speeds over 80km/h are not really possible with any margin of safety, no matter how much HP a car has. I love that in those tight switchbacks I can put essentially all the power on, and the car just pulls tighter into the apex instead of pushing out like so many other FWD cars do. I've had a few mk2 Sciroccos, and find the early chassis is night and day difference in this respect. So in my view, 120 HP or thereabouts is absolutely perfect and I think it's the point of diminishing returns where the efficiency and the benefits of the chassis start to degrade with more power.


      Quote Originally Posted by dougkehl View Post
      1. 11.6:1 CR pistons will be ok for pump fuel if you are planning to go efi, which it seems like you are. I am at 11.7:1 CR in my very high strung 1.9l 16v and it normally runs on leaded 112 race fuel, but on occasion it seems pump 93 and does fine once I switch ignition maps, otherwise you can tell it doesn't like the pump fuel too much. Knock sensing or more importantly, the ability to fire the spark at the correct time is the key to running pump fuel with higher compression ratios.
      I'm definitely an EFI guy; I ran a AEG motor on megasquirt and EDIS for many years in my previous car. So the engine will have very accurate fueling and ignition, along with a well-placed high quality WB02 sensor (which I know how to use).

      However after reading chopperoli's post about the pistons, I'm thinking that's not the right way. I don't know if the Pistons are the Woessner ones, but it's a safe assumption (Techtonics was not forthcoming with details, I feel like I'm bothering them)

      The idea of running a large cam with lots of overlap to lower compression just screams inefficiency to me, which is the opposite to my goal. I want to build an effective, efficient, intelligent motor. Not one with band-aids for poor parts spec. I do care about the emissions and I don't want to build a car that braps raw fuel out the back. I think initially I will stick with the G-grind I already have, get things running well, and look into upgrades down the line.


      Quote Originally Posted by dougkehl View Post
      3. Piston size. I think really this is up to you. It all comes down to how close to that original bore you want it or how far the block has worn which is more of the deciding factor than anything. For instance when I was building my 16v I had a very special set of custom JE pistons made, but I had to wait to measure the actual bore of the block. I was dead set on using 81.5mm pistons, which is .5mm over stock for a 1.8L 16v. I ended up with 82.5mm pistons which I'm very pleased with. I'd measure the bore and go from there.
      I think my block is pretty good as the compression is excellent and it has relatively low mileage. I definitely want to keep it a 1.6L. The biggest I would go on bore would be 81mm, for a total of 1648cc.

      Quote Originally Posted by dougkehl View Post
      You could look into using a set of ITB's because they will flow better than the stock intake manifold (big expense though) and maybe a bigger header, but these are things that aren't really necessary if you're not trying to squeeze every last ounce of power out of this engine, they do help no doubt about that. If you did want to spend some extra money and go with some ITB's, Jeveny just released a new product called the DCOE Heritage throttle bodies. They look like Weber DCOE's but the fuel injectors are hidden in the fake bowl of what looks like a carburetor. This is a wicked cool option for a retro racer style engine because Weber DCOE's were the go to for these engines to make more power and still are in many cases today, so it looks like you chose to go with carburetors, when in fact you get all the benefits of modern EFI. Here are some pictures.
      I do love the idea of ITBs, but ITB+Standalone seems to be a bit of a tuning nightmare, especially at idle. At that point you usually need to go alpha-N, which will almost always result in worse fuel economy than the speed-density algorithms. At least, that's what my extensive reading has led me to believe. The only way I would do it would be if I could get them breathing into a nice common airbox like the OEM BMW setups, with a good sized shared vacuum manifold, so that I can get accurate fueling and high efficiency at low throttle openings. Actually I would love to develop a vertical slide throttle body, with an angled valve plate, so that it almost acts like a variable diameter intake manifold:

      /
      ---/--------
      ------------

      I think this would really help boost the intake velocity at low throttle openings, and then get completely out of the way at large openings. The way the counterflow head sits, the throttle plate would come almost straight up and down, in the part of the runners where they angle down towards the ports. Picture a guillotine slicing the manifold in half across all 4 runners.


      For now, I will run a smoothed out OE manifold, with a modified mk4 tubular exhaust manifold, which is about as close as it gets to an OEM header. It has a beautifully placed WB02 bung right in the middle between the 2 runners where they go into the downpipe. In my old car the sensor was just in one of the downpipe tubes, and it never ceased to bother me that I was only getting 1/2 the engine's data. I think I'll just clean up the ports a tiny bit, gasket match the manifolds, and leave it at that.


      So... back to PISTONS!

      I definitely do not want any compromises. I really wish I could just get some nice .5 oversized OEM EG ones, so I can clean up the bore, balance the components, and get on with it in a very OEM way. But I have looked far and wide, and there simply are no sources of OE parts. How much of a compromise are the G60 pistons? From what I understand here, they just sit lower down in the bore. How come when you machine the block down, you then have to machine valve pockets, yet the OE setup works without valve pockets?

      Does anyone have a spec sheet for the OEM pistons, so that I can look into getting custom ones fabricated? It seems like that would cost less than all the machining required to get the other options working.

      Thank you all so much for your advice!!

    9. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      10-25-2016 10:01 PM #7
      Quote Originally Posted by chopperoli View Post
      Interesting, what are your 1.7 piston tops like? And what C/R? Are they Mahle?
      look just like EG piston tops, just a different compression height. Same compression, 9.5:1. I don't think they are mahle, I would have to check.

    10. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      10-25-2016 10:13 PM #8
      Quote Originally Posted by epic designs View Post
      How much of a compromise are the G60 pistons? From what I understand here, they just sit lower down in the bore. How come when you machine the block down, you then have to machine valve pockets, yet the OE setup works without valve pockets?
      G60 pistons have a 1.2 mm shorter compression height so the block would need to be shaved that much. The dish is not as wide as EG pistons so that is probably why you would need to machine valve pockets. Look into Ford Kent pistons, they were used back in the day and I have looked into using them for a big bore Heron.

    11. 10-26-2016 12:53 AM #9
      Quote Originally Posted by vwpat View Post
      G60 pistons have a 1.2 mm shorter compression height so the block would need to be shaved that much. The dish is not as wide as EG pistons so that is probably why you would need to machine valve pockets. Look into Ford Kent pistons, they were used back in the day and I have looked into using them for a big bore Heron.
      something like this?

      https://www.pegasusautoracing.com/pr...asp?RecID=4746

    12. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      10-26-2016 07:46 AM #10
      Quote Originally Posted by epic designs View Post
      yes but those are kind of expensive. They are forged though and not really needed for the street.

    13. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      10-26-2016 07:47 AM #11
      EG pistons have a compression height of 40.7 mm, 22 mm pin.

    14. 03-05-2017 09:19 PM #12
      kbob_999 has Oversize mahle pistons and a Eg 1.8 engin. In still building engine

    15. 03-21-2017 03:47 PM #13
      Well, I found the holy grail I was looking for!

      I have in my hot hands a complete set of new Mahle Pisons, rings, and pins, PN 034-63-03. Upon receipt, my only concern is that the spec on the box says the bore is 80,51 but the piston top is engraved with 80,48.



      Next step is to tear down my current engine and see what I'm dealing with. Hopefully there aren't any cracks in the block or anything.

      Obviously I'm going to need a complete rebuild / gasket kit for the EG.

      Anything else I will need? Am I correct in assuming that my crankshaft and rods will be fine to re-use?

      I'm going to have the block fully prepped after I tear it down. Going to have the rotating assembly balanced and remove the gas pump and distributor drive from the IM shaft. I was thinking of having the distributor hole welded completely shut as I will have no use for it. Good idea, bad idea?

      Excited to get started now!

    16. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      03-21-2017 06:42 PM #14
      Odd that the box would say 80.51 but the 80.48 is common for the Pistons to be tha size. The machine shop will measure them before they bore it. A gasket set for a US 1.6 will have everything you need. What exhaust are you using? Your crank and rods will be fine to use. You will need the distributor drive and distributor or some other means to drive the oil pump. What are you doing for ignition? I did not look back to see. What fuel system are you using?

    17. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      03-21-2017 06:47 PM #15
      I saw the exhaust manifold you plan to run. Do you have the special TT downpipe for a Mk2/3 manifold in an A1 chassis?

    18. 03-22-2017 01:08 AM #16
      vwpat, thanks for your reply!

      I don't have the downpipe yet but I plan to buy it when I reach that stage. Also I know the mk4 manifold will require lots of grinding to fit with the mk1 manifold. Longer term my plan is to use a dual IDF downdraft manifold and make a custom cnc'd perpendicular slide TB. But all in good time.

      So there is no difference between a US or euro 1.6 gasket set?

      Is there a better brand of these gasket kits? It seems everywhere I find them the brand and p/n is different. Also, half the gaskets included, I already have a better (rubber) version, or don't need it due to various mods.

      As for the distributor, don't need it, I am a big EDIS fan as I've set it up a few times and found it to be dead reliable. I've used a bunch of edis parts labelled "dead" that ended up working perfectly. I don't think its possible to break them, really; they work underwater FFS. I wish there was a way to completely eliminate the IM shaft, but its obviously necessary for the oil pump.
      Last edited by epic designs; 03-22-2017 at 01:48 AM.

    19. 03-22-2017 03:27 AM #17
      Any ideas for mounting an oem-style fuel rail to the EG head?

    20. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      03-22-2017 01:19 PM #18
      Only difference in gasket set would be the EG would have a different exh manifold to downpipe gasket but that does not affect you. You will need to cut the bars between the exhaust manifold ports other wise they will cover the intake ports. You will need a distributor there to run the oil pump or a "dizzy gizzy" like piece. 034 motorsport make the inserts that will allow EFI injectors to be used. As far as attaching the rail, you will probably have to make a bracket attached to the valve cover.

    21. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      03-22-2017 02:05 PM #19
      Seems like those adapters have been discontinued. I don't know of anyone else making them so maybe look for some used ones.

    22. 04-01-2017 11:36 AM #20
      Quote Originally Posted by vwpat View Post
      Odd that the box would say 80.51 but the 80.48 is common for the Pistons to be tha size. The machine shop will measure them before they bore it. A gasket set for a US 1.6 will have everything you need. What exhaust are you using? Your crank and rods will be fine to use. You will need the distributor drive and distributor or some other means to drive the oil pump. What are you doing for ignition? I did not look back to see. What fuel system are you using?
      very interested in this thread as I am leaning towards the same thing with my 80 Rocco

    23. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      04-07-2017 11:06 AM #21
      Quote Originally Posted by stereoandy78 View Post
      very interested in this thread as I am leaning towards the same thing with my 80 Rocco
      I have a complete, recently rebuilt Heron head and new, correct Pistons/rings for use with a 1.7 crank if you are looking.

    24. 04-08-2017 01:26 AM #22
      Quote Originally Posted by vwpat View Post
      I have a complete, recently rebuilt Heron head and new, correct Pistons/rings for use with a 1.7 crank if you are looking.
      Whats the difference, as mine is 1.6?

    25. Member vwpat's Avatar
      Join Date
      Oct 25th, 2000
      Location
      ATL
      Posts
      6,668
      04-08-2017 03:10 PM #23
      Quote Originally Posted by stereoandy78 View Post
      Whats the difference, as mine is 1.6?
      Difference in what? Pistons? The compression height is different for the longer stroke.

    26. 04-08-2017 06:46 PM #24
      i'm not sure what your goal is here. you say you want good torque low down and good high rpm power. it's not an easy thing to achieve without 16v or vvt of some sort. a bit of gasflowing together with a cam that's matched to your compression ratio is about as far as you can go.

    27. 04-10-2017 12:03 AM #25
      I'm really just trying to achieve full euro spec. In Kansas we don't need a cat or emissions, so I definitely want to do a a cam and header. My initial ideas was to do a ferfresh on the engine and shave the head with a good cam and porting and polishing. I'm trying to figure out the best route. It seems the euro version achieved this with the heron head and pistons. I love the idea of the square engine, as I know it gives me the ability to upgrade the Valvetrain and hopefully get around 120 or so. I've thought long and hard about a valver, but I would love to keep the 80/80 bore stroke

    Page 1 of 2 12 LastLast

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •