would like to know what sort of cfm your ported sohc rb30's have flowed on the bench? and if anyone know's what a standard head flows approx? would there be a big difference between machinists(spelling) when it comes to the porting?? only people interested in a good thread please as i dont think head porting has been discussed in detail!

std intake is 164cfm lol sad eh. ported in the bowl area and smoothing the short turn and de-dagging is around 180 - 185cfm the RB30 ports are a heap of sh1t, the intake floor is completely parallel to the deck and has next to no short turn. hopeless for good flow. they need major bogging or welding to flow good, bigger valves help a lot too, but 1mm OS on both intake and exhaust are getting close to contacting with a big cam. My head is getting some major work in the next week or 3, i will post flow figures here if u want. I have a sectioned head here to show how much meat is around ports if u want to see it lemmie know, its great for seeing how bad the ports are Cheers Brent Some original photos have not been recovered yet.

Pics......

damn thats a waste, would be keen to see your results as ive got a head being built at the moment...

waste of what? i was given a cracked head..... what exactly are they doing to your head?

i meant its a waste that they left so much meat in the port from factory.

Quote: Originally Posted by OOH30T i meant its a waste that they left so much meat in the port from factory, my head is getting 1mm oversized in and ex valves, solid lifters, heavier valve springs, billet retainers, a custom grind cam from lukevl and they have instructions to go as large as possible with the ports... dont know if their gonna go to the extent of bogging/welding! ah, ok is it a real head porting shop or a race engine building joint? size of the ports means nothing, shape is everything, if u want a nice head they have to bog / weld it, the size is actually good std. who is doing it for you?

Quote: Originally Posted by NZ VLCT ah, ok is it a real head porting shop or a race engine building joint? size of the ports means nothing, shape is everything, if u want a nice head they have to bog / weld it, the size is actually good std. who is doing it for you? pro flow in syd are doing the head, their more of a race engine shop but they do all their own machining etc. they will probably just clean up the ports etc. should probably give them a call and see how far their gonna go!

my head ported flows 130+cfm at 10''. i dunno how much that works out to be at 28''. but i think it flowed approx 90cfm on his flow bench ( which is a superflow) standard. if you want heads ported hes real cheap. about $500 for an rb30. done by roger at trinne performance in mildura. if anyone is interested msg me and ill give you contace details.

if you want to read up on flow and stuff like that heres a good site http://www.superflow.com/support/sup...wbench-faq.htm (http://www.superflow.com/support/support-flowbench-faq.htm) its good to have the port opening at 100% of the valve size then in the port just on the turn you want to go down to around 70-80% to create a venturi (gives air velocity) then back out to the valve. and another good thing is to get a 3 way back cut on your valves. give a good air flow gain at low lift. look at a ford cleveland 4v head for real big ports are better. good flow but no air velocity which = big hp no low down go whatsoever.

found out my head is about 190cfm at 28".

Quote: Originally Posted by OOH30T pro flow in syd are doing the head, their more of a race engine shop but they do all their own machining etc. they will probably just clean up the ports etc. should probably give them a call and see how far their gonna go! funny you should say that as i often see proflo jobs at my machinist's. their name is APM. steve and aaron hambridge who run the APM top alcohol dragster.

mine flowed 180cfm on the intake 28'' fatjake-wat did ur exhaust flow

Quote: Originally Posted by duz360 funny you should say that as i often see proflo jobs at my machinist's. their name is APM. steve and aaron hambridge who run the APM top alcohol dragster. fair enough didn't know advance performance do work for pro flo. either way im confident they will do a top job. should be interesting to see the results....

My head has been done by Gerry Cooper at Advanced Engine Performance in Brisbane. Heard many good reports about his work.. I'll have to see if i can get some flow figures..

Quote: Originally Posted by brettvlt mine flowed 180cfm on the intake 28'' fatjake-wat did ur exhaust flow he said he got it to 80-85% i think of the intake flow. he reckons thats what you want on a turbo car and around 70% on a NA. so i guess around 150-160 cfm.

Quote: Originally Posted by OOH30T fair enough didn't know advance performance do work for pro flo. either way im confident they will do a top job. should be interesting to see the results.... i believe them to be the best in the business. pro flo dont muck around either. your in good hands Some original photos have not been recovered yet.

Quote: Originally Posted by QIK86 My head has been done by Gerry Cooper at Advanced Engine Performance in Brisbane. Heard many good reports about his work.. I'll have to see if i can get some flow figures.. gerry did my head too ben , and my engine Some original photos have not been recovered yet.

206cfm at .500" lift on the intakes is what mine got (@28")

you get any flow figures andy?