4efte forged build guidance needed

Discussion in 'ENGINE' started by Harry1994gt, Nov 30, 2018.

  1. wickedep

    wickedep Registered Trader

    ah ok...now i understand the issue. actually spent a few minutes now checking online if there were any Taiho dealers listed online in the UK...didnt find anything useful after browsing through about 3 google search pages. :/
    SKINY and Jay like this.
  2. Padders_GT

    Padders_GT Member

    I tried to contact a UK company who sell Taiho bearings....they never answer their bloody phone.

    I'll keep you updated
    Jay likes this.
  3. Harry1994gt

    Harry1994gt Member

    Does anyone else here know wether machining the crank for 0.25 undersized Taiho bearings has any negative effects?
  4. H_D

    H_D Paid Member

    The crank journals have hardened material which you will lose. Many people who have gone down this route have had catastrophic engine failire.
    Harry1994gt and SKINY like this.
  5. Harry1994gt

    Harry1994gt Member

    Strange thing is, the fastest starlet i know of in australia is running 500hp on 40psi and NOS, he makes consistent 10.6's and after speaking with him, he did grind his crank and run 0.25 oversized bearings without issue and at such high power output
  6. Calum122

    Calum122 Registered User +

    But you really think someone like that is looking for reliability...cause you aren't going to get that running that much power.

    I'd hardly think it's his daily. And it'll go for a rebuild before the problem manifests. I think what they mean is, instead of the engine doing 200'000 miles on the same shells, it'll do 50k.
  7. Harry1994gt

    Harry1994gt Member

    Yes for sure i understand the maintenance required on a high hp car, this is no daily driver im building
  8. Harry1994gt

    Harry1994gt Member

    So ive made a start, done a bit of a u turn and now im back to building this thing for myself :) So i tore my block down

    It had spun a rod bearing and damaged a crank journal quite badly but i was not sure if it was too far gone for a regrind

    Also got my new forged spool rods with arp studs

    I took my block, main caps, crankshaft and new rods to the machine shop im using and had a look over the items with an engineer, straight away he measured and sore the damaged journal had worn down by 0.5mm. Too far gone for 0.25 bearings we plan to use.

    My block however seems to be ok, he is currently cleaning it up and measuiring it.

    We did make some decisions on what to do with it, we are going to use the ARP main cap studs for a 4age engine to stop the main caps from lifting, and will be running bigger than standard bearing clearances.

    Also we will use the 4age 10mm headstuds to stop the heads from lifting

    So today i went and got another 4efte crank, which came with a free block

    After removing the caps i discovered it too has suffered bearing failure and has damage on one journal, but it doesnt look anywere near as bad as my first crank atleast, oh well it was a freebie anyway, we will see when i take it to the engineer on monday, ive also sourced the arp headstuds and main studs so will take those to him also.

    We looked at bearings and all he could find were taiho 0.25 bearings although he did prefer ACL
    SKINY and Jay like this.
  9. Jay

    Jay Admin

    Great progress. All this groundwork at the start should give you a proper base to build on. To think some folks just throw them together eh?
  10. Harry1994gt

    Harry1994gt Member

    Yeah im definatly learning quickly, i have Rick from melbourne helping me alot, he has the 500hp 10 second 5e starket i spoke about. (i will comment below to a link to his video)

    Decided i am going to use Arias forged Billet pistons 74.5mm as these have been proven at high power by Rick, they are a turbo/nitrous piston and look way better quality than the likes off ross, wiseco etc

    These pistons give a CR of 8.5:1 with the stock head gasket i believe, i am machining the deck and head surfaces flat, i guess this will allow me to use a thicker mls head gasket and stick to 8.5:1.

    I am planning to run e85 fuel full time using 1680cc injectors, i know its not available in the uk so there probably isnt many on here who have used it but it has hugs knock protection benefits as well as burning cooler and having a higher octane rating.

    So bearing in mind i am running this type of fuel does a CR of 8.5:1 sound like the way to go?
    Last edited: Feb 10, 2019
  11. Harry1994gt

    Harry1994gt Member

    For those of you who havnt watched this its well worth checking out

    His best run yet 10.2 secs @ 142 mph

    Absolutely awesome car and legend of a bloke behind the wheel too
    Jay and SKINY like this.
  12. starles89

    starles89 Fresh Recruit

    im using pistons 74.5mm (wisseco) conrod MRX thailand, cam shaft 270,280 speedivisons, ecu piggyback dastec unichip Q4 ,turbo kinugawa TD04,bosst 1.5bar, CR 9.1 ,gearboks full close ratio straigh cut by NTM , result dyno run 325bhp,

    never reached the record of time 1/4 mile, 12sec??
  13. H_D

    H_D Paid Member

    Are you going to use the stock main caps?
  14. Harry1994gt

    Harry1994gt Member

  15. SKINY

    SKINY Registered User +

    That can shift on :eek:love the sleeper look of it too :p
  16. H_D

    H_D Paid Member

    For the sake of a few hundred £ more i would go for billet main caps if your budget allows it. The main caps become the weakest part of the engine at high power. People have had main cap breakage at as little as 300bhp.
    Jay likes this.
  17. Harry1994gt

    Harry1994gt Member

    I did look at these option but i couldnt actually find them for sale and available anywhere, do you know were i could get some?. My understanding of it was that the main caps bolts allow the caps to lift at high power and this is what causes them to damage bearings and or crack the main caps? I have spoken to rick about this and he has stock caps on his 5e although they are slighter wider than the 4e i think
  18. Harry1994gt

    Harry1994gt Member

    Also i assume the line boring would take away a minimum of a couple of thou, since i only can source cranks that need grinding at this point im not sure there are actually bearings available that would work with undersize crank and undersize caps, does anyone here run billet main caps?
  19. H_D

    H_D Paid Member

    Il find some for you. Bare with me a couple of days
    Harry1994gt likes this.
  20. Harry1994gt

    Harry1994gt Member

    I had a chat with the engineer about the main caps cracking, he thinks that will only happen if running too tight bearing clearances, especially at high power apparently he has seen it happen on other make/model cars. People forge and run high power but on the stock very tight clearances and run into issues. On my build we are going for around 2-2.2thou main and rod clearances which is quite a bit bigger than stock so we are pretty confident with the stock main caps, the bigger clearance will also keep things running cooler. I was happy to find when i got down there today he had already got the bearings and after him convincing me to use acl, he could only source Taiho
    SKINY likes this.

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