Is there any particular reason just about every cam i ever see favors the exhaust side (both duration and lift)? Stock and aftermarket alike. This seem slightly strange as the TPI intake is so restrictive. Just woundering if sombody could shed some light on this. I have a friend with a 5.0 mustang that swears by favoring the intake side.

 

Avg exhaust runner is between 45-75cc, and the valve is 1.60" or less in diameter.

-- Joe

 

Because the exhaust side of the cylinder heads is not as good as the intake. As mentioned the exhaust valve is also smaller. Some aftermarket heads do like single pattern cams though. My 355 said goodbye to me so now I will port my TFS' and am going to try a single pattern in them in a 400 sbc.

 

If you want more in depth info, you can always start researching I/E ratios (intake/exhaust) of heads. That should make it clear, and should also explain why certain cams perform better with certain heads. hth.

 

Thanks guys!

 

Tibo-what happened to your 355?
Did you ever get any numbers out of it?

 

I just finished dissassembling it last night. It turns out that it ate a few rod and main bearings. They were the Clevite 77 series. When I drained the oil the last time you could see the trail of metal dust in the stream. Not sure why it happened. Spin balanced and all. The crank will need ground and the block align bored. They always run best just before they go, only 5,457 miles on it.
Did not get to dyno it or time it, it was just fun and intimidating to others, that is all I really wanted. But now I am trading it for a 400 and I made a 305 out of some spare parts to drive with. Isn't it great, I am only 20 and have enough spare parts to make an engine. I decided to run the 305 in the snowy season and the 400 for the other parts. I am selling my whole HSR set up in favor of making a converted dual plane set up though.

 

Wow-sorry to hear that...hopefully the 400 works out for you...
Why are you switching to a dual plane setup?

 

Were you the kid in IRC/Chat the other night?

-- Joe

 

No, not me. It turns out that the oil bearing clearences on the connecting rods and mains were too tight and it ate the bearings, gouges ands cooper. Since the block is still good I am just going to do a splayed main 383 and put the 400 in the corner with the 305. I changed my mind again and now I will do a single plane. It looks cool and is easy and fun. Not many people have them. Just look at Anesthes'.

 

Ugg.. that stinks.

Good luck on the singleplane. Make sure you post pix to my site when you got it done

-- Joe