64 replies to this topic

[IronmanG]

So, what are the valve sizes you use/recommend (I am referering to the Pierce casted head) ?

I don't claim to be an expert. This is just 2 years of information building with the problems I had and asking a lot of people a lot of questions. Mine has valves it came with supplied by SC Couldnt tell you what they are of the top of my head. I think 35 31

Edited by IronmanG, 18 August 2023 - 01:14 PM.

[IronmanG]

Interesting stuff chaps, keep it up. Interestingly my (cast) head was supplied with C7 plugs, but I’ll be using 6’s for first start and initial running. Also it was supplied without injectors and I was recommended 180’s, 1275, SW8, 10.5:1. Time will tell how it goes, not using the SC ecu.

Is the sw8 your choice? I mean was it suggested to you by the supplier

It’s my choice, reason being, it’s used everyday so I want a usable spread of power, it’s only 1275 so a SW10 would probably be too much. However, it’s the only part that I haven’t bought yet, so I’m following this discussion with interest.

The RE cams seems to be the most recommended and the ones that seem to suit the head the most. SC and others recommend the re13pp.
If you think that's a bit feisty the re13ot winds it back a bit.
Maybe that cam profile just happens to suit the 7 port more whereas the others are more suited to the 5 port.

[OzOAP]

Careful on Cam/rocker choices on cast 7 port head. Spring topcaps hit top of valve guide at 0.360 lift 💩

Edited by OzOAP, 18 August 2023 - 08:08 PM.

[IronmanG]

Careful on Cam/rocker choices on cast 7 port head. Spring topcaps hit top of valve guide at 0.360 lift 💩

Maybe that's a simple reason why that camshaft is chosen. It's the only 1 that's fits easily🤣

[PoolGuy]

 

Careful on Cam/rocker choices on cast 7 port head. Spring topcaps hit top of valve guide at 0.360 lift

Maybe that's a simple reason why that camshaft is chosen. It's the only 1 that's fits easily

 

Oz’s post mentioned the billet head, now edited to say ‘cast’ head, what’s the op and others using, cast or billet?

[Java_Green]

I am building with a bare casted head. The intension is to open up for 35/31 valves and smooth out the ports from "cast edges".

[IronmanG]

Careful on Cam/rocker choices on cast 7 port head. Spring topcaps hit top of valve guide at 0.360 lift

Maybe that's a simple reason why that camshaft is chosen. It's the only 1 that's fits easily

Oz’s post mentioned the billet head, now edited to say ‘cast’ head, what’s the op and others using, cast or billet?

Mine is cast. Sonnik is billet

[IronmanG]

I am building with a bare casted head. The intension is to open up for 35/31 valves and smooth out the ports from "cast edges".

Just don't make the ports any bigger.

[Java_Green]

I am building with a bare casted head. The intension is to open up for 35/31 valves and smooth out the ports from "cast edges".

Just don't make the ports any bigger.

Thanks for your advise. I will not.

[Java_Green]

What kind of throttle bodies do you use, what is the runner length up to the butterfly and what is the diameter?

[IronmanG]

What kind of throttle bodies do you use, what is the runner length up to the butterfly and what is the diameter?

At power. Shortest that can go on to fit in a roundnose with a filter,40mm diameter. SC now do 38mm diameter. Still too big.
If you have a clubman that helps a lot to have longer runners and more torque like Sonnik

[Java_Green]

 

What kind of throttle bodies do you use, what is the runner length up to the butterfly and what is the diameter?

At power. Shortest that can go on to fit in a roundnose with a filter,40mm diameter. SC now do 38mm diameter. Still too big.
If you have a clubman that helps a lot to have longer runners and more torque like Sonnik

 

I assume you mean "longest that can fit in a roundnose" - to which I agree to. As I see it, the effective port length is all the way up to throttle or runner end - which one comes first. With throttle bodies, you end up with quite short effective port length. This should limit the low end torque. My knowledge is solely based on theory. Please feel free to share any experiencies. 

[Java_Green]

I hope Domenic Dent have got the information that he asked for. It is not my intension to hi-jack this thread, but the subject is so right for "7-port with injection in general". A subject that I think a lot of people find interest in and that I find would be good to discuss and share knowledge about. 

[PoolGuy]

I wonder if the relevant info could be imported into a general ’7-port’ thread?

[IronmanG]

What kind of throttle bodies do you use, what is the runner length up to the butterfly and what is the diameter?

At power. Shortest that can go on to fit in a roundnose with a filter,40mm diameter. SC now do 38mm diameter. Still too big.
If you have a clubman that helps a lot to have longer runners and more torque like Sonnik

I assume you mean "longest that can fit in a roundnose" - to which I agree to. As I see it, the effective port length is all the way up to throttle or runner end - which one comes first. With throttle bodies, you end up with quite short effective port length. This should limit the low end torque. My knowledge is solely based on theory. Please feel free to share any experiencies.

Sorry yep jet lag.
The longest I can fit which is also the shortest you can get.
Yes the theory suggests the torque will suffer. Whats interesting though is the torque holds on more at higher revs over the 5 port maybe 300 more rom which is why they give slightly higher hp
Really they need something in the region of 32mm ITBs and long!
Or what I'm currently working on is an airbox with a long 50mm pipe to allow the airspeed to pick up. That probably won't be ready to test until next year though