Large capacity type 4 build.

Discussion in 'Modified Shizzle' started by CandyCamper, Nov 13, 2016.

  1. I have just picked up the guts of a CJ lump :

    Which I intend to build into a torque monster for my late bay.

    So here's the start of the, how to what to, oh crap start again build thread.

    It'll be a slow burner as I intend to source the parts as cheaply as possible using other peoples eBay losses on over purchased parts etc to keep the costs down.

    I've given the lump a very quick once over on collection from just down the road, so far I'd say I'm up as I could sell the parts individually for less than the what I paid.

    So what's the sagely advice from those that have built a large capacity motor before - how big do I go - what parts should I look at?

    I'll be completely stripping, cleaning and inspecting all parts before going any further.

    Tom Wilsons book is in the post and the guy I bought the engine off threw in a copy of John Muir's How to keep your Volkswagen alive.

    Running total so far then....

    £206 - eBay CJ engine.
    £000.25p - diesel to collect

    Last edited: Nov 13, 2016
  2. Cheap lump. I fancy building a 'big' spare motor on a similar shoestring, so following with interest!

    nicktuft and CandyCamper like this.
  3. There are a few things to ask yourself before you start:
    What parts from the original engine do I want to reuse?
    Do I want to machine the crankcase and heads?
    How much do I want to spend?
    The answer to those questions will determine the engine capacity that is achievable reasonably easily.
    From the eBay listing I don’t see new lifters mentioned – you must use new lifters with a new cam and Scat Lube-a-lobe lifters are a good match for the cam. Incidentally the C25 cam is excellent for a bus.
    Let me know the answer to the questions and I’ll tell you what is possible, but I suggest you don’t keep a running total (it’ll cost more than you think) and throw away John Muir's How to keep your Volkswagen alive; it won’t help you build an engine.
  4. I have access to machining at reasonable or no cost as the father in law owns a engineering firm.

    As far as budget goes I'm looking to keep it to no more than £1200 but I'm not precious about this.

    However as already stated I expect to be building this slow time in order that I can exploit eBay etc so the build value may be considerably more.

    As for the running total -it stays, as I think it may be a useful resource for those wanting to go down the same route in the future and will also stop me getting carried away.

    Torque is what I want so all choices will be based around that...... I was chuffed to find the C25 already fitted when I read about its character!

    The book was free - haven't opened it yet but if it's dross it'll be recycled on eBay to add to the build budget, as will any serviceable parts not used.

    I'm in hope the case, cam, crank and heads are salvageable from this initial purchase...... it would be nice if the pistons and barells are serviceable and can be sold on.
  5. nicktuft, Deefer66 and Lasty like this.
  6. MorkC68 likes this.
  7. The standard crank is 71mm stroke and obviously if you retain it the only way to increase the capacity is to fit larger B&Ps. With machining of the case and heads 104mm B&Ps can be fitted giving 2413cc or even 105mm for 2459cc. Zedders engine is a 2413cc so this thread has just about everything you need to know

    Apparently it works very well with no overheating issues but those big cylinders have much smaller cooling fins compared to standard so that is something you may want to consider.

    My approach is very different. I retain the maximum strength in the crankcase and the maximum material in the heads so I have an 80mm stroke crank and 96mm B&Ps (2316cc), there is no machining required - but the parts cannot be purchased for £1200.
    Bertiebot and CandyCamper like this.
  8. Torque = square engine ....
  9. No. Big capacity = torque.
  10. it would help a lot of folks if you would put up some pics of your project from time to time
    CandyCamper likes this.
  11. O
    I will do. Nothing to show outside of the eBay pic at the mo though as I've literally picked it up this afternoon and put it in the garage prior to a return to the usual Sunday evening routine of getting the little one ready for the week of school ahead.
    Deefer66 likes this.
  12. Heres one for you to consider:

    its a VW modification to the con rods, item 4 on the list and illustration #2. Oil grooves on the conrods to keep the piston base cooler by splashing oil up. We have done the mod, I cannot guarantee it works or doesn't work!
    CandyCamper likes this.
  13. To avoid stress risers in the rod change the oil spray groove profile to a U instead of a V.
    MorkC68 and CandyCamper like this.
  14. But you went more 'square' than zed?
    Obviously it's hard to go exactly square but some guy on the samba went 80x80 in a bus . But closer the better ?
  15. we used the V shape but rounded the bottom/root out so we didn't create a stress raiser and cause a fatigue crack initiator :eek:
    77 Westy likes this.
  16. Yes I did, but not to make the engine squarer; I wanted maximum cooling and 104mm cylinders are close together and have very short fins.

    A long stroke engine will tend to produce maximum torque at lower revs compared to a short stroke of the same capacity (assuming similar heads and cam), but for any given permutation of bore, stroke, rod length etc. if you make it bigger it’ll produce more torque. It doesn’t matter if it’s made bigger by increasing the bore or the stroke or by forced induction. Size matters, but of course there are limitations.
  17. Love the engine threads..will follow with great interest;)
    CandyCamper likes this.
  18. Hopefully my experiences will help save you money and hassle. 2110cc T1 engine

    If running carbs, make sure you use 'velocity stacks' inside them, this may prevent things falling into your engine!
    A long stud (that held the airfilter onto the carbs) snapped and caused minimal, but bloody expensive damage when it fell into my engine

    See if there is anyway of properly 'leak' testing your crankcase before spending money and time machining it

    My T1 case was inspected, I was told it was good, it got machined, built up, fitted and tested before I drove it 100 miles and discovered it leaked oil.
    The crack was on the case under where the oil cooler sits. It was sorted by dropping an insert in
    CandyCamper likes this.
  19. Great thread I hope all the experienced engine builders contribute. That would be gold !
  20. So far....... I have purchased another complete GD code motor with all the tin and ancillaries.

    Add another £600 to the spend.

    So £806.25 so far.

    The strip of both lumps will start soon......however I'm a little distracted at the moment studying for a work based exam.

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