JMR Development blog

Discussion in 'JMRacing' started by mr hillclimber, Sep 27, 2011.

  1. mr hillclimber Club GTI Supporter and Sponsor

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    I'm going to try something new here...an "in brief" update with all things JMR... updates, results, new developments etc. If/when interest grows in a particular item we can poss pick it out and run with it in the relivent section. Feel free to dive in and ask about anything you see.

    So... to start the ball rolling...

    Jon Wright's hillclimb MK1...

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    Jon has been on the hill's in the same class as me for a few years now. He bought the car ready built with a throttle body equiped 1800 8v which had a solid 145 at the wheels, Quaife diff etc. Jon hooked into it quite quickly and started getting some decent times. Basic maintainance and an engine freshen up (similar power) over the years brought some good results, but the recent onslaught of Lotus Elise's coming through brought Jon to my door looking for some more grunt to do battle against the plastic fantastic's.

    We hatched a plan to build a brand new bottom end and upgrade the flow of the then current race head, along with changing the Newman cam to the proven cam/valve train spec I run. The car already had Jenvey 45's with Emerald management, Ashley 4-1 etc.

    So, in brief words and pics we have...

    A once rusty block sat in Jon garage for many years was stripped and found to have a little bore wear but suitable to clean up to take the slighlty oversize pistons I run to maximise the class capacity limit (A2 1400-1800). An increase to 1799cc was easy to achieve, along with some basic but thorough cleaning & block prep work.

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    Of course we cant leave it there as it needs some colour...

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    A critical but tedious job is getting the ring gaps right as they come as a "file to fit" ring pack...

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    After a day's worth of sore fingers we had all the basic elements in place...

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    There's some decent bits in the bottom end... Carrillo rods and custom JE pistons I had made to maximise the squish zone.

    The build came together hassle free...

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    ...and the head came up from it's previous 86cfm with the old 40.5mm valve's to 93cfm after some re-porting work, but Jon had a scrap head with 42mm inlets... well it would have been rude to leave them on the sidelines...

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    ...with some further port & throat work to maximise the 42mm inlets potential we managed to make 103cfm.

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    The head already had 35mm exhaust's so it's all a bit tight but it does fit...

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    Topped off with some decent breathing ability and my 318 degree race/hillclimb profile cam, Arrow steel buckets & lash cap shim adjustment, we were all ready for the dyno...

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    Thats just the dyno cam cover fitted so we dont have to worry about damaging a decent one when fitting on the dyno and dragging chain block's over the top!... plus I hav'nt done the proper one yet! :lol:

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    On the dyno it made all the right noise's and hit a peak of 189.74 @7,600... a bit down on what I expected but still just over 105hp per litre so not too bad, plus with the bigger valve head it's hanging on well with 186 @8,000 & 181 @ 8,500.

    The temp on the day in the cell was 27 degree's so not ideal, plus the oil pressure was "way" over the top from the new VAG pump.. but with no time to hand to strip the pump it had to stay as is. Plus the cam timing could prob do with coming back a touch, but that's being picky and time on the day just would'nt allow it... the engine came off the dyno at 6pm, I had it & the box back in the car by 10.30pm when I left the workshop that evening, along with most of the ancillaries... followed by the driveshafts and connecting up the fuel & water system the next morning, all ready for a 3.30pm MOT so Jon could tax it on line to race in the road class the following morning!.... not that we cut it fine or anything...

    The feedback so far is of a much faster car, with Jon having to brake hard in places on a familiar hill after carrying too much speed into a corner where a lift was sufficiant before, plus it needs the gearbox ratios sorting... the current Avanti box is much too tall geared with a 60+mph 1st, with only 1st & 2nd being needed on the hills. Along with some suspension work we're sorting over the winter it should be on the pace in Jon's hands.

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  2. fthaimike Forum Addict

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    A cracking read, 8v ftw
     
  3. R.b!n_16v Forum Member

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    nice read, love it!!
     
  4. mr hillclimber Club GTI Supporter and Sponsor

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    Thanks chaps...glad you like it.
     
  5. vw_singh Events Team Paid Member

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    Really really nice work on the engine Jason. Good to see someone still building proper N/A VW engines and sharing the info too. :clap:

    Gurds
     
  6. TDB86 Forum Member

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    That made a very interesting read Jason. Least we all have another port of call for decent workmanship :thumbup:
     
  7. Admin Guest

    :clap: great read, much appreciated. I would love to drop an engine off with you one day for some work.
     
  8. Tristan

    Tristan Paid Member Paid Member

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    what was the torque curve like Jason? cracking work , as always.
     
  9. tones61

    tones61 Forum Member

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    me and jas putting in the engine

    :thumbup:

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    :)
     
  10. MK1-Tron

    MK1-Tron Forum Member

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    Great work Jason! Well done Jon with the results!

    Love the idea of the blog, makes for an interesting and inspirational read and promotes the quality of JMR's work :thumbup:
     
  11. drunkenalan Paid Member Paid Member

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    Nice! As always 8v power rules
     
  12. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    According to those values the torque in the tail end was:

    131.1lbft@7600
    122.1lbft@8000
    111.8lbft@8500

    The torque may be diminishing at these points but by comparison one should consider that a fettled itb'd 2.0 16v road engines as seen in smudge and NigeP vehicles, will achieve 110-115lbft, some 1000rpm short of this heavily modified 1799cc 8v unit and still pull a heavier vehicle with some pace. In those 2.0 16v engines the torque diminishes much faster than this 8v example.
    Of course the tail end of a power and torque plot does not tell the entire picture regarding if the torque was any greater than 131lbft as well as did it plateau or was it peaky.
    Gearing will be critical for application too.
     
  13. mr hillclimber Club GTI Supporter and Sponsor

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    Gurds... proper?... well it's ok I guess...;)

    TDB86... [:$]...

    Smudge... yr welcome... come on down anytime...

    Tristan... fairly flat/spread but down a bit over what I normally see on this spec/cam... which is another reason I think the cam isnt right... there was'nt enough exhaust lift @ tdc with the inlet lift as I normally set them... but the performance in the car say's it's not that much of an issue.

    tones61... you almost got my best side!... and thanks for working like a trojan that night!

    MK1-Tron... cheers Scott...:)

    Alan... 8vFTW!!!

    Eddie... Just over 135 peak, never dropping below 120ib/ft from about 3-1/2- 7-1/2K from memory... the figures are at the dyno... which is some way off the norm on this spec... we did play a little more on the road will a laptop but it wont have changed much. In car performance is more than good... it pulls 780 kilo's like a train in just 1st & 2nd on a very long ratio box after breaking the short ratio one (with a 60+ mph 1st it's way too tall). With the short ratio 4 speed (4.7 f/d), the owner came back after a squirt up the road and only revving to just over 7 and said "Jeeessus"!... his wins the weekend on the long box tell the rest. I'll have a proper look at it again when I have it back over the winter.
     
  14. mr hillclimber Club GTI Supporter and Sponsor

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    Right... something I've been meaning to get on with for a long time... the 8v crossflow head.

    A few have tried them in std form with great results (George HH?), and after testing a customers conventional "race" head with the normall missing flow and the poor guy having been "done" by an expert in the stitch up process, we've elected to go the crossflow route... so out came the test head (thanks tony :)) to see how far we can push it.

    I started looking at these last year with very good initial results. The std crossflow head has a 39.5mm inlet valve and flows 83cfm as std v's the conventional type with it's 72-74cfm from a 40mm inlet valve...so a positive start for the crossflow.

    Initial light throat/seat work still retaning the 39.5 valve brought that up to an easy 90cfm, so similar to the 88-90cfm from a ported 40mm GTi head, but, with a 0.5mm smaller valve, and, with better low & mid lift flow. That was were I got to last year.

    Following on over the last couple of weeks, I had a measure up and it looked like a 40mm GTi valve will just go on the std seat without changing the insert...I'm all for this as it's a cost saving, but would re-working the seat/throat to suit produce another positive step forward?

    Starting with opening out the main inner seat/throat diameter then creating a bottom cut of a 3rd angle type with a burr so as to blend the throat & seat contact together...

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    ...the rough edges are knocked off and we go in with the bad boy to create an undercut & give some throat area to go inline with the bigger seat area...

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    It looks mullered here but it's not... just a little short turn re-shape...

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    ...and a quick blend off with some emery tape to tidy. Note the work is all in the seat & just into the throat area...

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    Acording to the flow bench the crossflow likes a valve size increase... I was expecting a gain of around 3cfm so was happy with 4!... we now had 94 cfm from a std 40mm GTi valve, a good bit better flow than many so called race heads on bigger valves, and all from std parts with a little re-working. Here is a comparrison with a conventional head on the same 40mm sized inlet valve...

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    As can be seen it's not just at peak flow the crossflow is better but right through the lift range... and remember that flow increase into the cylinder is happening as the valve is opening & closing... so an effective increase.

    In terms of power potential, here's the curve with a conventional race/hillclimb head I did on 41mm inlets which went on to make 188hp on the dyno (another 1800 hillclimb spec engine)...

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    So the crossflow has all the potential to work well even on O.E valves. So that's that then.... naaah....:lol:

    The crossflow head we're currently working on is the later swirl type with an odd shape lump in the main throat/bowl area, and a shallow short side turn shaped to help the swirl lump spin the air/fuel mix. Now this maybe just a pure emmission thing or there even maybe a further power advantage, but as we're looking to improve the flow and the std combustion is very good... it's gotta go!

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    As can be seen above... the "lump" has been cut back as far as just breaking into the head and finding fresh air!... hence the band-aid/plastercine!

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    So what did that do to flow.... well... in two stage's, first with the a fair bit of the lump removed, flow came up to 96.7cfm, and then with some further light detailing of the seat and short turn we're so far up to 98.9cfm... all from a std size 40mm inlet valve.

    And below, in it's current form to date with Tony Barber's 40.5inlet... and we all know how well that goes!

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    Further increase's could be possible with more cutting back in the bowl, but that will require welding and shaping on a running head... I think the plastercine may melt with petrol being fire's at it... and we've yet to explore a proper big valve option... 41-42mm or maybe bigger...[:D]... I'll be working on that soon.
     
  15. Tristan

    Tristan Paid Member Paid Member

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    interesting result! Crossflow ftw so?
     
  16. Toyotec

    Toyotec CGTI Committee - Happy helper at large Admin

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    135lbft is what a very good KR engine develops at its peak with around 120lbft peak from a healthy yet nominal engine. In a vehicle that weighs a mere 780kg that level of twist spread over that engine range of 3.5 to 8K rpm will make such a vehicle seriously surge forward pending axle torque.
    If the torque can be made to slighty increase towards its peak and diminsh more slowly towards the end, the performance both from a number and driver aspect will be improved.
    Cam timing w/calibration development would be the direction I would take assuming the engine in the current setting is already at MBT/LBT for the conditions.
     
  17. mr hillclimber Club GTI Supporter and Sponsor

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    Oh it certainly seriously surges....

    Looking at the figure's from the previous 1799 8v, the torque peak on that engine was similar and at similar rpm, but fell away faster at the top with 127, 118 & 103 @ 7,500,8 & 8,5... so the latest engine is a touch stronger and hangs on better at the top. We later ran it on the rollers and picked up more mid range with an increase of advance... time did'nt allow this on the latest engine. The torque spread on the earlier 1799 made 114@ 3,500, 122@4, with a peak of 136 between 5-1/2 & 6-1/2... I'll check the new engine tomorrow.

    The best 16v I've seen to date (not my engine, just fitted the DTH's & mapped it) was a 2ltr that made 141 ib/ft @ 5-5-1/2, 149@6, 147@6,5, 142@7, 132@7,5.
     
  18. Jon Olds Forum Junkie

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    Excellent thread Jason, is the 1799cc a hone job, over std? Did you use an affordable kit? I have a +010" block to do.
    8v's rock. Anybody thats built both, in race spec, will know how much easier an 8v is.
    Head work looks 1st class
    Like to try an x-flow
     
  19. mr hillclimber Club GTI Supporter and Sponsor

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    Hi Jon...thanks alot.

    I did'nt do the hone myself, that was a job for my machinist. I would'nt call his K kit affordable... think he said it was 12-14K a few years ago... similar spec new now is around 18-20. He took 16 thou out from memory.

    Yep... love um! I think with the current potential of the crossflow head there's more than enough power available without going OTT. Thanks Jon... there's still a touch more to come from the old style head but they're getting close to optimum without going trick... like setting in a downdraught port tube... scrap head, ally tubing... guess what's coming... ;)
     
  20. Tristan

    Tristan Paid Member Paid Member

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    woo hoo! I often dreamt about this , but never had the nerve to chop one up!
     

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