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My Hybrid Project got some questions along the way

17K views 100 replies 7 participants last post by  Mr. Wood 
#1 ·
So I finally got myself a EJ25 short block case off from a 2012 STI and im planning to acquire the following parts next week.

- JE hybrid pistons
- King Rod and Main bearing
- STI harden crankshaft

1st question should I get the 04 to 06 version STI OEM head gasket or the 07 to 13 version STI head gasket?
 

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#6 ·
quick update I got almost of the parts already ..my boss just wont let me go on leave for me to assemble my hybrid :(

I have the following parts any comments about them?

- JE hybrid forged pistons
- Manley rod
- King main and rod bearings
- sti 11mm oil pump
- gates racing timing belt
- kinugawa fuel rail

right now I cant decide if ill get a stage 2 or stage 3 competition clutch .. any advise on this?
 
#7 ·
if its a daily driver i would recommend staying with a sprung hub. solid hubs are a pig to drive and really only good on the racetrack.

a twin plate, organic clutch, sprung hub (whatever "stage" that is) is a nice setup. the orgainc material keeps things smooth over ceramic, but with 2 plates its better enagagement and holds alot more power.
 
#12 · (Edited)
Hmmm.. I can't daily the stage 3? The seller said it can be a daily ..but I guess his the seller will say anything lol!
you CAN daily anything at any "stage", its just a matter of what u want to put up with while driving. but stages are a marketing term and i have no idea what you mean by stage 3.

is it sprung or unspring, organic or ceramic button, twin plate or single?

stage 3 might or might not be ceramic button clutch, with or without cusion.

see where im going with this? "stages" sell products... but doesnt really tell us about the item you are purchasing.

the seller is telling the truth im sure. it would defeinitely work. but have you driven with a solid hub clutch before? also what are your power goals? if your aiming for 500-600-700hp you might need a really strong clutch. so the one you have alreday selected will be fine.

your clutch is probably the hardest part to select properly for your car. its the piece that connects the car to the foot to the road to the feel of the car. too hardcore of a clutch can really ruin the way a car drives.


everything else looks nice btw :) i like when ppl take the time to paint things during rebuilds... unless your building a ratrod lol :)
 
#10 ·
my kinugawa fuel rail .. the problem was I spent 2 weeks prepping my tgv I deleted it .. clean it.. remove the butterfly.. cut the divider plate.. clean it again and paint it .. just to find out it does not fit my STI intake manifold and the injectors.
 

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#14 ·
thanks titter I always like my engine clean looking. btw speaking of HP do you know how much horse power my wrx 02 tranny can hold up? ill be replacing my tranny with a sti 6 speed one later on. im just wondering how much HP it can handle for now.
 
#15 ·
how you drive is 90% of how long your trans lasts.

ive seen stock 5speed hold 500hp, yet stock wrx's blow thier 5mt all the time.

there are cars running 700+hp on the stock 5 speed with this as their only upgrade Moore Performance & Race Parts - BlastPlates

learning how to heel-toe shift and match synchros can greatly reduce wear on your transmission. some say this is uncalled for for daily driving, but those same people say 500hp is uncalled for for daily driving so ignore them. everything is relative.
 
#19 ·
thanks again titter day by day I learn so many things from you didn't know about this blast plate before .. ill try to get my hands on this part I think I need it.... I don't race my car and I rarely do above 80mph again im so scared of the cops here in California ..but I do have a bad habit of doing hard takeoff from time to time.
 
#18 ·
I havent assembled my hybrid engine yet.. most probably around May ill do the swap. But yeah i do have the OEM head gasket already which im actually thinking twice of using. I was going after the cometic gasket at first but they say block and head surface should be perfect flat or else the cometic will fail... OEM gasket they say will not fail due to surface issue?
 
#21 ·
Check out Southbend clutches, they're a little pricey over some but my stage 2 daily paired with a competition clutch flywheel engages like stock with 350+whp holding capacity.

Any flywheel under 12lbs will be annoying to drive in stop and go especially with the a/c on, but will be very happy in the high rpms. As for both the pulley and flywheel, it depends on your tuner for how well they they adjust for the reduced rotational mass. You may get a P0300 you might not.
 
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#25 ·
So i'll start assembling my crank tom. I would like to confirm this.. I have a Manley rod the data sheet says the torque should be 90lbs. but I have been reading around most recommend the torque should be 65lbs with 30W oil or 45lbs with ARP lube.?

I'm off only Mondays i'll start with the tom. next week i'll assemble my block.
 
#27 ·
its been several months and I'm still not yet done with my hybrid project cant seem to finish it due to work. Anyways I'm done with my short block. Just a quick question. Can I use JDM heads for this hybrid project? with JDM cams and cam gears? Its an EJ20 still so it should be the same with USDM right?
 

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#28 ·
im pretty sure u can use JDM heads but you will still need them chamber matched and youll need a JDM ecu.

JDM heads would be better due to the bigger ports and better cams. your problem will be the AVCS. the usdm ecu wont run avcs and im not sure how the jdm ecu likes hybrid builds. i have never heard if a jdm hybrid build.

you're right about the EJ20 part. if i was to hazard a guess, everything should bolt together no problem and fit in your engine bay. wire in the avcs like you would an EJ207, plug in the JDM ecu, and then fire it up and tart tuning.
 
#29 ·
okay brother I think its time for me to be honest :( i'm actually done with my project. my boss wont let have a week leave vacation for me to finish my engine.. so what I did I got myself a fresh JDM low millage engine took it apart to completed my hybrid. now I don't have to ask my boss a week off I can probably do a whole engine swap in 1 to 2 days. Before getting the JDM engine I did a research and ever thing should be the same. Now here is my major problem I was doing a compression test yesterday and sad to say air is coming out again from the intakes all of them. I don't know if I bent all of my intake valves which I triple checked the timing belt alignment and they are still pretty much aligned. or stupid me I could have switched the cams intakes/exhaust on both sides. Because its like the piston is going up already and the intake valves are still in the open position. I think the pistons have traveled half the cylinder already before the valves will totally close. right now I'm thinking the JDM Cams or cam gears might be different from USDM. really need help on this one :(
 

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#33 ·
yeah stupid me did not check the valve clearance before installing everything I'm not sure right now if Rallysports Direct shipped me the wrong valve size anyways i'll find out once I remove the head again ... looks like i'll be grinding some valve wish me luck lol!

thanks! this is what I have been working on for couple of months now.. ill post some more photos once I'm done :)
 
#35 ·
the stock 205 heads dont like to be spun over 7500(ish) and ive seen them handle 400(ish)whp.

i would be more worried about your 15 year old seals in your head. the metal parts are fine, but everything is else and might be on it way out...

getting some head work done isnt a bad idea. alot of people say to themselves "well im just gonna stay shotckish levels, maybe a bit more, maybe 350ish" then 350whp comes and you still want more. its fine, its only natural. so do the work to handle 4-5-600whp and if you dont ever reach there then you can feel safe you have an overbuilt motor to last you a long ass time.
 
#36 ·
7500 rpm 400whp is fine by me :) .... i rebuild my heads already replaced all of the valve seal. The problem was the GSC performance valves i got the length is about 1mm longer than my stock JDM valve I don't know if Rally Sport Direct shipped me the wrong valve size or its because my heads are JDM heads. The GSC valves are 1mm longer making my valve clearance zero or -XXX causing my valves to be open all the time. I could replace all of the shims for me to still use the GSC valves the problem is its hard to find a supplier for the shims... so right now i have no choice but to install back the OEM JDM valves.
 
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