turbosigma2

A serviced M7 head complete with roller rockers on Australian ebay recently didnt get a bid. Trouble was the guy wouldnt post. Said it was too big to post. Maybe back on soon ,who knows. I have M1 and M4 heads. both with roller rockers fitted. Some guys over here think that the M4 makes a better street turbo head than the M7. I have never had a M7 so I cannot comment. Australia had a fectory Mitsubishi Sigma suck through turbo in 1981. It was fitted with the 4g52 Astron, but came fitted with a stock 2.6 factory camshaft. I guess that Mitsubishi think that the 2.6 cam is close enough.

Tried the Magna forums and did no good. Pointless trying the local Starion forum as 99% of them use the 4g63.

Not for Mitsubishi. Still a limited suplly of GM and Ford OEM parts. Biggest spares chain here is Repco. They have access to anything that's out there, but drew a blank on the Roller cam. One of the problems is that that particular motor had such a short production run. The previous motor had standard rockers with hydraulic lash adjusters, and the next model Magna had the 2.4 I have sent off a couple of emails, i'll keep you posted.

I am running a different car ,but a similar motor. Only thing left is the PCV ventilation system. Providing that you car is fitted with one. I had a similar issue with a new motor. Had it pulled down to find the problem, and there wasnt one. Engine builder sujested a much bigger ventilation system than stock. So I run a PCV from a GM V8 and similar sized tubing. No more crank pressure issues.

M9 heads can still be had new, but it looks like the roller cams are almost non existant. Crow cams are the biggest supplier of standard and modified cams in Australia, and they do not have any. http://www.crowcams.com.au/media/catalogue...ni%20,Sigma.pdf

Just a bit of background. The 4g54 roller rockers were fitted to Australian built Magna's between 1992-1994. An average one would have 200,000 miles on the clock. Most heads and valve gear would be from stuffed Magna's. in wrecking yards. Chances are the components will be a little worse for wear. V6 rockers on the other hand were made from 1994 to 2007. Maybe able to still find new items, but items from wrecks would still have useful life left in them.