Thread: Need My Head(s) Examined

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Cayne -

I can't claim to know much about what I'm talking about... and as 65ny stated above, the car will probably be drivable if not pretty fun. I would say there are some fairly glaring mismatches among the rect heads, small exhaust, and tall rear gear... I'm not sure how much pain any of this will cause. I don't know a whole lot about cam-shafts but it seems this one is ground more for low end torque which compliments the size of your exhaust and the rear gear. I would probably lean toward oval port heads to bring everything in line for good lower rev combo, the peanuts might overdo it.

The other route would be keep the heads, go bigger on the exhaust (at least 2.5" probably 3" better) and a shorter gear in the rear (maybe 3.80:1+) but I don't think that cam is meant so much for the high end.

I'm fairly new to this stuff so I may be off base a bit... there are some really sharp BBC guys on here that will probably chime in with more reliable info.

At any rate, have fun!

Chris

Originally Posted by skids72

Cayne -

I can't claim to know much about what I'm talking about... and as 65ny stated above, the car will probably be drivable if not pretty fun. I would say there are some fairly glaring mismatches among the rect heads, small exhaust, and tall rear gear... I'm not sure how much pain any of this will cause. I don't know a whole lot about cam-shafts but it seems this one is ground more for low end torque which compliments the size of your exhaust and the rear gear. I would probably lean toward oval port heads to bring everything in line for good lower rev combo, the peanuts might overdo it.

The other route would be keep the heads, go bigger on the exhaust (at least 2.5" probably 3" better) and a shorter gear in the rear (maybe 3.80:1+) but I don't think that cam is meant so much for the high end.

I'm fairly new to this stuff so I may be off base a bit... there are some really sharp BBC guys on here that will probably chime in with more reliable info.

At any rate, have fun!

Chris

Thanks for the input skids. Being on a budget, I toyed with the idea of throwing those peanut ports on there for quite some time and asked several people their opinions. Generally speaking...people either loved them or hated them. My biggest fear was running out of air around 4000rpm but I could not find a set of good ovals for a decent price so when I came across the rectangular ports I snagged them thinking I could resell them if I decided not to use them. After SEVERAL WEEKS of trying to make up my mind, I finally decided to sacrifice some low end torque and go with the 990's. You offer two very good future options and I totally agree with you.

Funny thing is...I spent weeks and weeks reading everything I good about building engines and the "marriage of parts" and I think that I have thrown it all out the window. I am still curious as to what I can expect in terms of problems with this setup. I have heard that (bad) setups can be a bear to tune and will generally be a pain to keep running and so I am hoping that is not so. Hopefully I will get some more insight from other members so I can see what the general consensus is.