I've got a brand new engine with 96mm bores on a 2.0L crank, the heads have been decked a little and it has a "hot" street cam. It also has dual Dellorto 45's on it.

I have only driven it a 3times but it's becomming apparent that I've got heat issues. I think I still have low or mid grade gas in it.

When she's cold it runs great other then it's a cold engine on carbs. But my oil sump temp gauage is getting up there. It's telling me that the oil temps are reaching 220F which I think is around 110 -->115C f memory serves. Not to mention when it gets that hot it runs like crap-o-la and it feels like I start dropping cylinders.

At some point in the cars history the thermostat bellows was removed and in it's place someone installed a plate to block off 30% of the air flow on one side to direct it into the oil cooler. The drivers side of the motor is wide open into the cowling.

I have made sure that there are no holes in my fan system and have topped up the oil to be 100% full.

I do hear some pre-ignition knock when I put by boot into it as well.


So I'm wondering how much of a difference the higher octane will help? Or if I need to start looking at other things?

Thanks!

-JR-

If someone has monkeyed with the air cooling system, fix that first and foremost. No gas will help you if you are robbing your engine of cooling air. Make sure the flaps are in place and not in the incorrect position.

Well right now it's wide open, no air respretiction. But they put a baffle in place so that the oil cooler still get's it's share of the air.

Apparently this is fairly common.

My car runs significantly cooler on 91 and higher gas. Also, timing set too high will cause big heat. Dial that thing down. What is the timing right now? When my car runs hot, it has been effected most by:
1. timing
2. overly lean mix.

You need higher octane if your cam is pretty steep- the earlier the spark fires ( big static advance) the more you're gonna need an even, progreeive burn like you get with higher octane.

It would be a simple test. Get a tank of the good stuff and knock a few degrees of advance off the diz. What kind is it anyway? Ol' .009 WOT advance is sumthing like 40 degrees. Thats too far.
BTW, for a setup like you describe, I think you will feel the difference in performance too.

Hi
Take it from a fellow Canuck, put the tin back to stock.
I have personally battled a "hot" issue, with my 2.0l, everything was put back to stock, no problems since.
even in 30+ temps
The factory t stat (new) and cooling tin works surprisingly well, but it was miss understood and often ripped off the motor.

Good luck with it
Later