Stock head flow rates for 20v?

[TERRA Operative]

Has anyone got any stock flow rates for the silvertop or preferably, the blacktop heads?
I'm trying to work stuff out, and I'm having trouble finding these specs.

Thanks.

[Billzilla]

Bottom of this page ->
http://www.billzilla.org/4agstock3.htm

[TERRA Operative]

Sweet.

Few questions... Is that intake or exhaust side, also, what units is the lift measured in?


You wouldn't happen to know what the quad throttle bodies flow would you?

[gixer]

I did flow some ST throttles years ago, from memory at 20inches of water each throttle flowed 256cfm, I have to go and check my records. I recently flowed an ST head then ported/flowed/ported/flowed etc and got some really sweet gains on the exhaust side, also got some really good gains cleaning up where it splits into the three intake valves...if that makes sense. Once finished the head flowed some really good numbers. Also de-shrouded around the outer intake valves.

[TERRA Operative]

Nice. Do you have the flow charts at all?

[Billzilla]

Sweet.

Few questions... Is that intake or exhaust side, also, what units is the lift measured in?

It's both sides, with the higher flow being the inlet(s)
And now that you mention it, I don't know what the units are for the lift! lol
It's just a little chart I got from a mate years ago.

[TERRA Operative]

I assumed the higher line was for the intake, so that's all cool. I made the assumption that the lift is measured in 10th of an inch, but 5/10 of an inch is 12.7mm, which is way over stock lift...


I happen to have a complete stock head here, so I might go and get it flow tested (ITB's too).
I'll post the results if I do so it can be made easily available for everyone.

What does that sort of thing cost to get done?

[oldeskewltoy]

I know this isn't 20V... but here are some flow #s for a large port head... stock, and with mild porting

[TERRA Operative]

Nice, I might create templates for the small and bigport and the silver and blacktop for tinkering etc.

Is the small port specs anywhere too? Will help when I come to do my 4AGZE. I got a spare smallport head, but I'll get it flowed if there's no info out there.

[jeffro ra28]

As far as price for flowing goes it will be much cheaper if you get it done by someone who already has the jig for a 20 valve. Perhaps someone that specializes in them.

Paying the local speed shop to build the appropriate jig will way exceed the cost to freight the head to a 20v guru

If they have all the jigs, then it is probably only about an hour job for setup and testing. Special rates may apply to flow testing and not your usuall $80 an hour etc tho.

[TERRA Operative]

Yea, true. Hope it all doesn't cost to much, all for the sake of some templates in Engine Analyzer Pro... Awesome software that.
Does anyone know of any shops that have the jigs??

I'll definitely get the blacktop head flowed regardless for my build though.

[jeffro ra28]

Id start by calling Mark Yager..............
Google "yager performance"

[Sam_Q]

I did flow some ST throttles years ago, from memory at 20inches of water each throttle flowed 256cfm, I have to go and check my records. I recently flowed an ST head then ported/flowed/ported/flowed etc and got some really sweet gains on the exhaust side, also got some really good gains cleaning up where it splits into the three intake valves...if that makes sense. Once finished the head flowed some really good numbers. Also de-shrouded around the outer intake valves.

thats interesting, can you explain what you did to the intake port dividers?