Hi there!!

Well it all started in the beginning of 2010/mars With a lot of problems.
I sorted thing's out but didn't really get the problem that i had.
Well at the end of the season we had a trip to the track and had a few runs with sucess and fail, last run the engine blew..
The best run before the engine blew for thoose who want to see.

http://www.youtube.com/watch?v=HOZnKPe9tVc

Well now everything is put together again with all new parts.
Cylinder head
Kelford 280/276
Kiggly race spring/retainers
1mm os stainless valves
Fully ported and cnc head
Flow tested with 240 cfm at 0.250"

Block
Std crank
Manley I-Beam rods
Wiseco hd 86mm bore
With other brand new parts.

I run aem ver 1.19

So i started this new engine up last week and it seemed to run fine..
But i had some trouble to get the afr right.
And i noticed that there was one cylinder that had a little compression so i cheked.
1=3bar
2=7bar
3=7bar
4=6bar

That was not ok so i took the head off and checked the valves with E85 ethanol.
There was leaks at most from the cylinder 1 exhaust valves.
And minor leaks from all the other valves.
I had this problem before, like 4 times...
Damn.. Wel i checked the valves, and there is no marks on the valves and no marks on the pistons that will say that there is no problem with the timing/timing belt.

I have checked piston to valve clearence and there is at least 6mm+ clearence with full open valves at booth sides.

What could it possible be that i having this problem, i have talked with at least 10 engine shops here and there is none that has had this problem.
Don't know what to do anymore.

I got one tip today, that i have to check the valve length into the head.
I Checked a std head and it was 47mm exhaust.
Maybe someone of you guys have the std value for the valve.

http://cgi.ebay.com/ebaymotors/MITSU...Q5fAccessories

That is the valves that i am using, notice many of my friends are using these valves without any problems, but maybe i should change to supertech valves or something?

I would be very greatful if you had any suggestions what i should do to prevent this in the future!!


//Anders

 

ive heard alot of people use those valves with no problems, as you've said your friends use them too so its not the valves. Are you sure the valves aren't bent? I would find out about the valve tip length.

 

Did you replace the valve guides? If the guide has excess wear it might allow the valve to tip and maybe not seal.

 

The valves are not bent, they have been regrinded in a mira maschine.
And The guides is not changed but there is no reason to change them because they are ok. (i used a dial indicatorm to check them.

I bought new 3mm lashers now and hopefully they will work a little better.


//Anders

 

yeah lifter pumped up and holding the valve open?

 

That was my first tought to.
So i have tested 4 or 5 different sets of lifters.

Anyway i did order now 3mm lifters and then hopefully they will be working as they are brand new.

Oilpressure is kind of high, but nothing more than someone elses evo engine.

2bar working temp 80c + oiltemp
cold start is about 7bar.

Kiggly does have a oil pressure reducer for the head and keeps the pressure to 20psi i think.
But he said that his part will not solve my problem.

It's a littly tricky this problem.

 

Did someone have the installation height for the valves??

 

No one had it i'll guess!!

Well the installation heights for the valves is 100% perfect anyway.
If we see this a little further, maybe the head is not the problem at all??

I have Aem ems 30-1310
And coil on plug ignition (300m coils)
and a microtech ignition box.

Shall i change the dwell wizard or shall it be as standard (mitsubishi coils)??

When msd dis-2 is used it must be changed in the aem wizard to all cdi otherwise it the msd will burn.

so maybe if the dwell is to high, the sparkplugs gets to warm and it starts to really warm in the cylinder and that's why all valves are leaking after so little time.

I don't know but it is a good suspicion.

Is there any aem gurus in here?

Post some pics from aems software and my sparkplugs that melted my pistons.










//Anders with problems

 

Were the valves lapped before being installed? if you have a CNC head with a valve seat that has been cut you should always lap the valves or you could have sealing issues between the back cut on the valve and the freshly cut seat

 

Well the same thing happend on another stock head so it is not the head that is the problem.
The valves are laped.

/anders

 

melted spark plugs are usually from poor tuning resulting in detonation and/or EGT too high. Are you running det cans on it when you're tuning?

 

What is = det cans? =)

I only have my aem gauge and we run 11.5afr on full boost, (2.5 - 3bar) with ethanol e85
Egt is never above 860celsius.

 

det cans = noise cancelling high quality headphones hooked up to a knock sensor.
are you tuning on the road or on a dyno?
you could be going past MBT

 

Allright i know what it is but we don't have that equipment, we are tuning on road.
And what does MBT stand for? =)

 

Maximum brake torque. The point (of ignition timing value) in which you make maximum torque for a given RPM. If you're running e85, you can go past maximum torque by adjusting ignition timing too advanced. This is why dyno tuning is so beneficial, you can accurately measure the torque.
If you're still melting spark plugs, pull the timing a whole bunch and try again. Your AFR's will not be affected.
You should be running some kind of detonation detection, even more so when you're road tuning. But in saying that, E85 is very hard to get detonation (knock).
who is actually tuning your car?
Do they have a lot of experience with E85?