Time to start my rebuild project

[hybrid]

Not sure that cam (or the heads) will allow 500+ at the crank.

[malscar]

Lee, just wondering why you didn't slot the brake discs?

[boofhead]

Cool - thanks for the specs. Nice street engine.

[LEEH69]

malscar The Horses are engraved into the surface similar to how a slotted rotor is, so will do a similar function,
I had done quite a bit of research before making all the brake parts, and what I found from a brake specialist( not saying proven)
the average driver of a street driven (not a race car) would not feel the difference between a good vented rotor and a drilled slotted rotor.
But I can add that at a later date if need be

[LEEH69]

If any of the Guru's out there think there is a more suitable cam, I an all ears

[boofhead]

I tried looking at the camshaft question. What I was expecting did happen in terms of the calculations; Any way
1) 6000 rpm you need somewhere around average 270 cfm flow to provide enough air. Which equates to around 400 thou lift flow rate when using a close to 600 thou lift camshaft.
2) The heads cannot supply enough air - Pro1 195 flow un touched in the order of 260 cfm at 600 lift. Not bad in their day but not great compared to latest modern heads.

So what does this mean;
1) You need to run a lot of duration to get the airflow window to feed it
2) The get the cam events close to right you will it to be a tight LSA figure

The risk is that you will loose alot of the bottom end due to reversion affect from longer overlap period. Secondly, you may not get the air through any way to port sonic choke at higher revs. So could be a dog.

So your second choice is a far better camshaft as it is a longer duration camshaft (+20 deg over current) and tighter LSA at 110.

My figures were more like 250 deg @ 50 and a LSA of 106. In practice might be to large as indicated above.

So I would look to similar figures to the howards but on a 108 center.
So your not bad picking the camshaft.


BTW: 399 cid

[LEEH69]

cheers Boof, for me it's an educated guess, but still guessing,
The heads aren't exactly stock they had been previously ported etc, and today I ported the runners to the manifold to the heads,
I may consider changing the heads at a later date but I'll see how these go first, end of the day it will be a strong street car not a race car, so not chasing every little bit of performance,

[boofhead]

Well ported Pro1s are far better than as cast. So you might be good. Do you know the flow figures and the new runner size?

Most port them to around 201 cc intake runner to start getting far better flow from them.
You are on the right track for your purpose.

[lukep6470]

LEEH69 Take a look at the videos I posted for Boof. That is a 347 with a 230/240 cam and the motor is silky smooth once you get it over 1300 rpm and has surprisingly more pull than I expected. I would do a standing start video but I am surrounded by 40/50 zones and there is a high blue presence in my area due to a major rat run. The motor only bogged as I was in 3rd at 40Km/h when I floored it (You can't hold a camera phone and manually shift at the same time).

ITB's are more forgiving for larger cams.

So my cam peaks at 6200 and I think with ITB and bigger CI you could go a much bigger cam than me.

[Shaunp]

Lee while you have the heads off, find someone that can do a 5 angle valve job on them if you can.

[LEEH69]

The heads aren't off Shaun but that doesn't mean I can't take them off,
maybe a dumb question but how much of an advantage is the extra angles

[LEEH69]

sorry Boof I don't know the runner size as they were ported by my engine builder about 8 yrs ago

[LEEH69]

Luke, video looks and sounds great,
I noticed your air filters, as that's another thing I'm looking into, without disrupting the airflow, not sure yet but may make an air box

[hybrid]

Sorry I missed the Howards cam mentioned in your post.
It was the Lunati 221/223 @ 50 thou cam that I was saying would not be big enough.

[LEEH69]

No worries Jeff, all good mate