4efte forged build guidance needed

wickedep

Trader
Yes we know Taiho supply Toyota. But to find a Taiho dealer who sell the 3 different types of STD main and big end bearings we are struggling. If anyone can that would be a great find.

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. :/
 

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
 
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Yes you can, but a lot of cranks are nitride coated which only penetrates so far into the metal. So if you re-grind them you can lose that hard nitride coating, which isn't ideal.

I don't know if Toyota did nitride the 4efte cranks or not, but that's a general insight. If you can get away with not re-grinding the crank it's always best as long as the oil clearance between journal and bearing is correct. You'll find a lot of these ' Tuning / Performance engine builders ' don't even do oil clearances, they just slap any old std bearing in, and that's a fact! I've seen it done so many times! Tuning Developments cough cough....


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

Calum122

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
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.
 
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.

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


https://imageshack.com/a/img922/2686/OMn94O.jpg

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
 

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?
 
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?

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?
 
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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
 

starles89

Fresh Recruit

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
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??
 

H_D

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.
 
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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.

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
 
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?
 
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
 
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