Anyone have any info on flow numbers for 305 heads? Stock or ported is fine.

Thanks!



------------------
Current
86 TA 305 5 speed, hardtop
81 Z28 350, 4 speed, t-roof
99 Ducati 750 Super Sport

Former
85 Z28
94 TA

 

You 305 freak, wtf is wrong with you. You should just scrap the 305 and drop in a real engine. lol
I have no data, perhaps pablo does, i don't know how much research he did before he used 416s (LG4/L69/early LB9 heads) onto his TBI. He may very well have used them b/c he had them on hand.

but in a non-tech light, how you been. Long time no talk. You use AIM or ICQ? I'm notgetleft, and my ICQ # is 21047979 as before. I don't remember if you were around then, but my 85 was stolen the night before the night before christmas 99. Spent time in an 83 GP LG4 that i resurrected from basket case. Gave that to my sister and picked up my 92 Z28 vert...stock except free mods and a dynomax cat back with the muffler backwards (straight shot Ipipe->Tpipe, other Tpipe gets whatever pulses through the muffler.) It'll come along eventually, expect a sleeper w/ secrets.
...ed

------------------
Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

double post

[This message has been edited by Ed Maher (edited March 13, 2001).]

 

Kevin,

I'm guessing you have the 14014416 castings. These heads have 1.84/1.50 valves, and small port sizes to match. They may or may not have swirl ramps above the valves, depending upon who you talk to (mine didn't).

These heads flow about 177 SCFM at 0.500" valve lifts. Since a stock '86 305 has the "LA" cam, the lifts never even exceed 0.400, at which point the flow is less than 159 SCFM. In a word, these heads suck (or don't suck, depending upon your point of view). They can be made to flow better with larger valves and better cam, plus they can be ported around the valve bowl area and runner radius areas to improve flow. Raising the roof of the ports a little helps, and the TPI system can tolerate a little more port volume without penalty.

The big problem is the valve spacing in the necessarily small chambers, inducing some valve face shrouding and flow impediment. There are some tricks you can do to both the valve faces and margins and the chambers to recover this lost flow, so a little judicious machining can get you a lot better flow rates. None of which can do a lot of good without a better cam profile, however, because even well-ported heads don't flow much more than 200 SCFM below 0.400" valve lifts.

Hope that helps.

------------------
Later,
Vader
------------------
"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader