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Discussion Starter · #1 ·
Hi, I completed my turbo install and everything runs great besides for 2 major problems.

1. I can not seem to find a spark plug that will last. I tried the E3 spark plugs that are recommended in some other threads but they only make it 300 miles before they melt down.

2. At 10 psi of boost i can run all day. At 30+psi of boost i can get about 10 passes before i burn an exhaust valve. At 20psi max i can run about 300 miles before i burn an exhaust valve.

Both problems are heat related. I think that i am pushing to much air/fuel into the engine and it can not exit fast enough. Which is causing to much heat on the exhaust valves and melting my plugs and exhaust valves.

I know i can install inconel exhaust valves and stainless steel intake valves. The problem is i can not find any for the sohc head.

Stronger valves will fix the valves burning but it wont fix the spark plugs melting down. I am thinking a camshaft that will allow the engine to breath better will fix the exhaust temps. But i can not find any turbo cams for the sohc head.

I already have a 3" down pipe and 3.5" open exhaust out the back. There is a muffler but it does not restrict the flow.

I am hopping someone on here that runs high boost on a sohc will chime in with some advise.

Thank You
 

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Discussion Starter · #4 ·
I run duel ecu, stock ecu with no custom roms. and i run mega squirt for my fuel management. I always run slightly rich. through my rpm range i never see my gauge run lean and my engine temp never gets above 200.
 

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Discussion Starter · #6 ·
Yep it is automatic.

I took the head off today and i did not burn a valve instead i burned a piston.

I went to the local machine shop and talked to the head machinist about different valves and pistons. We looked through the parts catalogs at valve specs and we could not find anything stronger that we could make work.

What valves are people using and where are they buying them?

We also talked about coating the head, piston and valves to help direct the heat but he said they do not do that in his shop and he was not sure where to go.

Is coating the combustion chamber necessary?

We also looked for a cam with more duration for the exhaust valves and we could not find anything for the sohc head.

Does anyone have a supplier for performance parts for a sohc head?

Thank you
 

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I suspect you have a timing control and knock/preignition issue more than anything but that could come down to the SOHC head also, it's not got the cooling capacity for sustained high power levels. The DOHC head has more robust cooling and is built for boost and higher output from the get go. It breathes better, it cools better, it has more aftermarket support. Hate to say it, but you'll probably need to swap to a DOHC head to meet the power goals you seem to be aiming for.

Look for a thread buried in this forum by Bosiro87 or something like that, he had a 4G64 auto that was pushing boost like you are.
http://www.club3g.com/forum/members/361.html that guy! I was way off on the username!
 

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Discussion Starter · #9 ·
Thanks for the advice.

I am going to switch to dohc

so far i have bought
272 hks cams
8 inconel exhaust valves 1mm over
8 ss intake valves

I am not sure if i should go with the kia or the hyndia head but as far as i can tell they are the same thing. What ever head i buy will come with the intake. is there an advantage to the kia or hyndia intake? i have found a few of each that i can buy the whole car for cheep.

also i have read contradicting threads on if i need adjustable cam gears
1 don't need them just use two tensioner pulleys
2 don't need them just use 94 galant belt
3 don't need them just use the evo belt "it is a pita but you can get it on"

everything else i read said i need at least one adjustable pulley

i have also seen contradicting threads on valve springs and retainers

do i need to change my valve springs and if so do i just need to upgrade them or do i need to switch from the kia/hyndia to the evo? is there something different about them?

will the retainers and and keepers work with the evo valves?


I was also thinking about the timing curve being to much. The stock ecu controls my timing and i have not done anything with that for tuning. the only tuning i can do is on the fuel management. I do know that i have no knock codes under the factory ignition tune. would the stock ecu see knock and retard the timing without tripping a code? and if so could i still have to much timing and that would be melting my spark plugs? even tho there is no knock?
 

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Greetings, one quiestion, do you have a pyrometer install in car this may help to see the exhaust temps pulling out of the motor, other question, are you only tuning the fuel , or are you also tuning the timing?
 

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Discussion Starter · #11 ·
i do no have an exhaust temp gauge. I also do not have a way to tune my timing. I did buy a tactrix cable but it broke the first time i used it. called the company and they said they no longer carry the product and they could send me a replacement chip if i wanted to solder it in myself. they said it would take up to three months to receive it.

so i installed a mega squirt for the fuel management and i am using the stock ecu for the timing. no knock codes at all and the engine ran fine.

i was reading about running on e85. from what i understand you can alot more advanced timing becuase the engine runs so much cooler. is there any truth to it? is it common to run 2.4 dohc turbo on e85?
 

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Discussion Starter · #13 ·
Does anyone know the stock max timing advance for a 2001 2.4 eclipse? &
Does anyone know the stock max timing advance for an evo8?
 
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