Type 4 cam choice and lifter compatibility help please…

Discussion in 'Modified Shizzle' started by madmansi, Nov 2, 2015.

  1. Hi everyone

    I’m planning on using either of the following cams in my 1911cc type 4 engine build to gain a little more low end power and torque;

    Webcam 73
    Eurorace C
    Scat C25

    I’m leaning towards the Scat C25 as I’m struggling to find a supplier of the other two, -does anyone have any experience of the Scat C25 quality/performance wise?

    Will I be ok to use new stock (likely Brazilian made) lifters with all the above cams? –was worried about potential wear issues due to a miss-match of materials/hardness.

    Any help appreciated!
  2. 77 Westy

    77 Westy Supporter

    I’ve used a Scat C25 cam with standard followers in my 2.0 type 4 for the last few years. A good spread of power, the oil is always clean with no signs of debris and the valve gaps haven’t needed adjustment. I’ve just done three thousand miles in three weeks driving from near Lyon to north of Aberdeen and back, it goes okay considering it’s just 2 litres pushing a 2¼ tonne brick along.
  3. Zed

    Zed Gradually getting grumpier

    I'm building a 2.4L T4 with a std 2L cam. I like the way a 2L goes. It has about 11mm valve lift which I think is enough. I haven't masses of experience but I'm put off aftermarket cams by the moving of the power band too far up the revs. I want grunt.
    nicktuft likes this.
  4. nicktuft

    nicktuft Supporter

    I totally agree a fully loaded van needs low down torque.
  5. Zed

    Zed Gradually getting grumpier

    It may well be el crappo but I've convinced myself I'll have anout 140-150hp of pure grunt. I'll report back in a few weeks.
  6. What cam did /do they put in the 914 412 1700 and 2000's ?
  7. Zed

    Zed Gradually getting grumpier

    Ah, well that is the $6,000,000 question.
    Some say they differ, some say they are all the same.
    The smaller engines seem to have run higher CR,
    The smaller engines go like hot snot at higher revs compared to lower revs.
    The smaller engines have bigger valves.
    The 2L bus engine IME has loads of low end grunt, yet happily and freely revs :thinking: that's through 37.5mm valves. Knowing very little, I reasoned that by making a 2l bigger cc with bigger valves to match and some decent carbs should make an engine with the characteristics of the std 2L but more of it. I might be giving up a little potential max HP, but I don't care about that, I want van driveability this time. I may look silly when it's done but I think not. :cool:
  8. 77 Westy

    77 Westy Supporter

    The SCAT C25 is pretty mild – especially on larger capacity engines – 0.430” (approx. 11mm) valve lift and 272deg duration, power band from idle to 4,000 rpm, it’s definitely not a high rev racing cam.
  9. Zed

    Zed Gradually getting grumpier

    So they say. I have a sneaking feeling - well it's obvious really - all these things are meant for beetles or other light cars for the T4 stuff. The cam profiles on offer today were designed in the 70's and we're still stuck with them. Scat couldn't give a fook, they have half the market.
    nicktuft and lhu1281 like this.
  10. All three are pretty mild and generally used in buses to give a bit more power and torque lower down the rev range;

    Webcam 73; 0.426"/262deg
    Eurorace C; 0.425"/270deg
    Scat C25; 0.430"/272deg

    Unfortunately there aren't many suppliers in the UK as far as I can find.

    The Scat C25 is tempting cost wise if its designed to work with stock lifters, I think the Webcam 73 officially requires webcam lifters.

    A torquey 2056cc build would be nice but 2L cranks seem a bit thin on the ground at the moment so looks like I'll be sticking with the 1.8L crank and going to 1911cc.
  11. Aftermarket cam followers are crap. I use original solid ones reground with a slight radius, they are much softer on the cam. As for cams, You need a cam ground with a decent base circle not one that has been re profiled. Ebay has "914" cams for sale from time to time and they are always re profiled. Do people really think that VW and Porsche would use a cam like that? I have built dozens of 1911cc type 4 engines and they work very well even with the stock cam. If you choose to fit one get it hardened, tuffriding works well. Robert
    nicktuft likes this.
  12. 77 Westy

    77 Westy Supporter

    Does anyone know who manufacturers the standard cam and what the specification is? It would be interesting to compare the valve lift and duration to the aftermarket alternatives listed earlier.
    I’m surprised nobody else is using a Scat C25 cam. It might be a 70’s design, but it has a good specification with good torque from idle. It’s cheaper than standard but not a reground or re-profiled old cam and it works well with standard solid followers.
  13. Zed

    Zed Gradually getting grumpier

    I don't think anyone does. I'm using pre-loved one.
  14. I will be selling type 4 re machined and hardened when I get my crankshaft grinder up and running and modified to do it. There are several different cams fitted as std. VW never listed any data for them just as they did for the type 1.
  15. 77 Westy

    77 Westy Supporter

  16. Is that welded and reground ?
  17. The camshafts that I will grind will retain a lot of the original base circle. I had them done from the late 70s until I took a break from VWs in the mid 90s. I have brought a Prince Crankshaft Grinder and when it has been stripped and all the worn parts replaced I will move it to my new machine shop and hopefully modify it to grind cams, if its not possible then I make something else to do the job, simples. Please don't throw away any worn Type 4 cams. Robert
  18. I must confess I know a bit about engineering but nothing about cam shafts .....if a cam is worn surely by grinding more off it'll have less lift than original ?
    I saw I think a wheeler dealers program where they took the cam shaft to a place where they built it all up with weld and machined it back to standard ...not a VW though
  19. 77 Westy

    77 Westy Supporter

    To retain the original lift whatever is ground off the lobe is also ground off the base circle, the lift and timing is the same as the original but the cam is smaller. However, to minimise valve train loads the base circle needs to be as large as possible, which is why Robert said “You need a cam ground with a decent base circle not one that has been re profiled.” and “The camshafts that I will grind will retain a lot of the original base circle.”
  20. ah i see ..... but it will have a slight effect on things tho ? like you need enough adjustment on the rockers albeit minimal and duration will be ever so slightly affected ? how much are we talking material removed 0.25mm ??

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