I know I differ in opinion in many ways from some here but I will still share my sadness with all of you. Today at the Superlap at Arroyo Seco 3rd lap into first session my Cosworth M3 Mivec intake cam broke at the oiling points.

Had these cams for 2 years or so even pre build. (actually first set in AZ)

Intake side hit and marked the pistons but cylinder 2 and 4 exhaust valves are bent even though they looked as if they never touched.. Thanks to a poorly design flaw in the Cosworth cams my JAM stg 3 block and head need to be completely refreshed...

Looking to do the Tomie 270 11.5 pro cams + higher compression pistons next... will see what Jam has to say. Im not going to rush the build but continue to build it right and avoid future pit falls like this. Interesting note though this was on 1.7 Bar with 87 octane!! , notice how there is no sign of pitting and very little carbon on a motor that has been together for almost 2 years. You can tell with direct port every cylinder has been getting a equal distribution of H20... :mrgreen:

Ill keep you all updated with what Im doing. JAM has been freaking awesome and this bottom end is so strong rods + crank are completely fine.

Evan Smith

 

dammm

 

There goes my plans for Coswoth 280's.

 

google "My intake cam snapped"

For real that is why i sold mine

 

I snapped one taking the pulley off when I was replacing these cams. That was a cosworth m2.

 

That's a real horror story, sorry for the damage to your nice engine.
But what's up with running 1.7 bar on 87 octane?

 

direct port water injection

 

87 Octane... I'm surprised to say the difference wasn't as big as I thought with the knock threshold between 91 and 87. Very little timing was removed in my maps. Water is really good at controlling the burn and eliminating hot pockets in the cylinder.

It was a test (for the past week) to see how well direct port water can hold up to knock on 87 and see what the difference was. When I compare with my 100 oct no H20 tune the results are pretty astounding. Im not going to post up my findings until I can complete all my test (including dyno) but for now Im stuck! Stupid cosworth! lol Plans was to run the tank out (1/2 tank) and fill up on 91 for the T/A but oh well.

Its cool the SPARKTEC non CDI does so well at keeping the spark strong I have NO blow out with a .025 gap! Thats with OVER 840CC of 100% H20 injecting. Its funny coming off being 100% TPS upon decel you can hear the leftover water as it cycles out of the motor just causing a small spark blow out because its the only thing in the cylinder as the injectors are at 0.0 % duty cycle.

The guys at the track are like "hey there is clear liquid coming out of your exhaust after the straights is your car ok?" LOL

EGTS are very consistent at 800C or less! and oil temps never have seen above 202* F yet! NEXT test... (VP's)100, 109 and 116 octanes + h20 and then dyno the ones that seem to have the biggest gains not just peak power.



Evan Smith

 

Sorry to hear about your event and associated losses.

Like someone else mentioned above, there was a series of MIVEC intake cam failures right around this same time last year. MIVEC intake cams from GSC, Kelfod and Cosworth failed in the same manner as yours, leading to the consequences that you are now well aware of. For this reason I uninstalled my Kelford 272's before something happened to my motor.

Hopefully you get to fix the car relatively soon so can keep enjoying it out on the track.

 

Thanks to all... What I wish I knew... lol I didn't keep reading about cams after I made my decision 2 years ago.. this wasn't a evident problem as the kelfords were just being release. Oh well...


The learning curve on the EVO is an expensive one lol


Evan Smith

 

This was a common issue with all of kelfords, cosworths and gsc's early batches. They have since fixed this issue with the new batches. If you send it the broken cam to cosworth, they should replace it no questions asked. Sucks that you had to suffer other engine damage though.

 

Same thing happened with my Evo's Cosworth M2's

 

Dam that sucks that would be nice if Cosworth would.

 

what happes if there is a H2O leak and you not getting the proper flow? are you gona fry anything? are you injecting the h2o in the intake pipe?

 

^^^ I have a total of 5 jets 4 into each port one down stream the Aquamist flow gauge is set so that if a break in the line dose occur the gauge will show maxed out. I check the lines at least 2x's a week.


Ill be adding another jet soon

Evan Smith