F.A.Q.    Register    Login    Home Members    Search

Toymods » Tech & Conversions » 4A: G vs F heads Show: Today's Posts  :: Show Polls  Email to friend

Author	Topic
Bill Sherwood Forums Junkie Location: Brisbane / Gold Coast Registered: May 2002	Re: 4A: G vs F heads Tue, 26 October 2004 03:42 Shraka wrote on Tue, 26 October 2004 13:02 As I understand it, and I'm just getting this off of Bill's site, a close angle head is better as you can have higher compression pistons without needing to dome the top of the piston (as much?). That's at least one reason. As for Toyota F series heads, aren't they usualy economy heads? So wouldn't they have smaller valves for more torque, and completely different cams/tuning/parts all for low revs? So you would have to change a lot more about them to get any performance. The next question is, why did Toyota go with wide angle heads for performance applications in the first place? It's probably a technology thing, but perhaps someone else on here can clear it up. Err, Bill? Yes, a shallower valve angle means a smaller chamber (34cc on the F heads) and so a smaller done on the piston. Small, or no domes are best for flame propogation. The valves in the 7AF heads are the same size as the G heads, 30.5mm and 25mm. I'm going to be using 32.5mm and 27.5mm though. I don't know the reason for the last question sorry ... though ... Norbie wrote on Tue, 26 October 2004 13:33 You might want to ask Yamaha that question... they seem to be a big fan of wide valve angles, and the heads they designed for Toyota reflect that. Have a look at an 18R-G head one day, talk about wide! This was in the 70's though, so I guess times have changed since then. .... I've never been impressed with any Yamaha head. Either the ports are too big, wrong shape, or just fundamentally wrong in some important way. The gen4/5 3SGe heads aren't too bad though. [Report message to a moderator]

	Subject	Poster	Date
	4A: G vs F heads	Henn	Thu, 21 October 2004 13:47
	Re: 4A: G vs F heads	Norbie	Fri, 22 October 2004 00:06
	Re: 4A: G vs F heads	rob_RA40	Fri, 22 October 2004 00:09
	Re: 4A: G vs F heads	b1gb3n	Fri, 22 October 2004 02:26
	Re: 4A: G vs F heads	rob_RA40	Fri, 22 October 2004 04:51
	Re: 4A: G vs F heads	b1gb3n	Fri, 22 October 2004 06:15
	Re: 4A: G vs F heads	Bill Sherwood	Fri, 22 October 2004 04:01
	Re: 4A: G vs F heads	EVOSTi	Fri, 22 October 2004 06:15
	Re: 4A: G vs F heads	ae95	Fri, 22 October 2004 06:19
	Re: 4A: G vs F heads	SEXY 16	Fri, 22 October 2004 06:41
	Re: 4A: G vs F heads	wuzah?	Fri, 22 October 2004 10:51
	Re: 4A: G vs F heads	NuGeN	Fri, 22 October 2004 11:41
	Re: 4A: G vs F heads	Henn	Fri, 22 October 2004 13:34
	Re: 4A: G vs F heads	Bill Sherwood	Fri, 22 October 2004 14:16
	Re: 4A: G vs F heads	Henn	Fri, 22 October 2004 15:13
	Re: 4A: G vs F heads	cwhelan	Mon, 25 October 2004 01:59
	Re: 4A: G vs F heads	drift86levin	Mon, 25 October 2004 03:03
	Re: 4A: G vs F heads	b1gb3n	Mon, 25 October 2004 07:53
	Re: 4A: G vs F heads	takai	Wed, 27 October 2004 21:52
	Re: 4A: G vs F heads	SEXY 16	Mon, 25 October 2004 09:23
	Re: 4A: G vs F heads	Bill Sherwood	Mon, 25 October 2004 10:09
	Re: 4A: G vs F heads	SEXY 16	Mon, 25 October 2004 21:27
	Re: 4A: G vs F heads	Johnny	Tue, 26 October 2004 02:27
	Re: 4A: G vs F heads	Bill Sherwood	Tue, 26 October 2004 02:57
	Re: 4A: G vs F heads	Shraka	Tue, 26 October 2004 03:02
	Re: 4A: G vs F heads	Bill Sherwood	Tue, 26 October 2004 03:42
	Re: 4A: G vs F heads	Norbie	Tue, 26 October 2004 03:33
	Re: 4A: G vs F heads	mrshin	Tue, 26 October 2004 04:15
	Re: 4A: G vs F heads	Shraka	Tue, 26 October 2004 04:53
	Re: 4A: G vs F heads	Bill Sherwood	Tue, 26 October 2004 05:04
	Re: 4A: G vs F heads	b1gb3n	Tue, 26 October 2004 05:04
	Re: 4A: G vs F heads	Bill Sherwood	Tue, 26 October 2004 06:28
	Re: 4A: G vs F heads	Shraka	Tue, 26 October 2004 06:45
	Re: 4A: G vs F heads	mrshin	Tue, 26 October 2004 06:17
	Re: 4A: G vs F heads	Norbie	Tue, 26 October 2004 06:51
	Re: 4A: G vs F heads	Shraka	Tue, 26 October 2004 07:25
	Re: 4A: G vs F heads	Bill Sherwood	Tue, 26 October 2004 07:53
	Re: 4A: G vs F heads	Johnny	Tue, 26 October 2004 10:49
	Re: 4A: G vs F heads	mrshin	Tue, 26 October 2004 14:17
	Re: 4A: G vs F heads	oldcorollas	Tue, 26 October 2004 14:27
	Re: 4A: G vs F heads	mrshin	Tue, 26 October 2004 14:36
	Re: 4A: G vs F heads	quest	Tue, 26 October 2004 15:36
	Re: 4A: G vs F heads	b1gb3n	Tue, 26 October 2004 15:48
	Re: 4A: G vs F heads	4DaDrift	Tue, 26 October 2004 15:50
	Re: 4A: G vs F heads	Shraka	Wed, 27 October 2004 00:08
	Re: 4A: G vs F heads	Bill Sherwood	Wed, 27 October 2004 01:49
	Re: 4A: G vs F heads	oldcorollas	Wed, 27 October 2004 15:22
	Re: 4A: G vs F heads	Tofuboi	Tue, 26 October 2004 21:53
	Re: 4A: G vs F heads	Shraka	Wed, 27 October 2004 02:02
	Re: 4A: G vs F heads	quest	Wed, 27 October 2004 06:30
	Re: 4A: G vs F heads	quest	Wed, 27 October 2004 06:59
	Re: 4A: G vs F heads	quest	Wed, 27 October 2004 07:21
	Re: 4A: G vs F heads	oldcorollas	Wed, 27 October 2004 07:34
	Re: 4A: G vs F heads	Henn	Wed, 27 October 2004 06:58
	Re: 4A: G vs F heads	Shraka	Wed, 27 October 2004 07:31
	Re: 4A: G vs F heads	takai	Wed, 27 October 2004 07:58
	Re: 4A: G vs F heads	quest	Wed, 27 October 2004 14:32
	Re: 4A: G vs F heads	oldcorollas	Wed, 27 October 2004 15:08
	Re: 4A: G vs F heads	Tats	Wed, 27 October 2004 23:26
	Re: 4A: G vs F heads	Johnny	Thu, 28 October 2004 00:48
	Re: 4A: G vs F heads	Shraka	Thu, 28 October 2004 02:21
	Re: 4A: G vs F heads	Johnny	Thu, 28 October 2004 03:44
	Re: 4A: G vs F heads	Bill Sherwood	Thu, 28 October 2004 04:30
	Re: 4A: G vs F heads	b1gb3n	Thu, 28 October 2004 05:24
	Re: 4A: G vs F heads	koen	Thu, 28 October 2004 04:52
	Re: 4A: G vs F heads	Norbie	Thu, 28 October 2004 05:09
	Re: 4A: G vs F heads	justcallmefrank	Thu, 28 October 2004 05:24
	Re: 4A: G vs F heads	Bill Sherwood	Thu, 28 October 2004 05:17
	Re: 4A: G vs F heads	Bill Sherwood	Thu, 28 October 2004 05:29
	Re: 4A: G vs F heads	oldcorollas	Tue, 02 November 2004 08:10
	Re: 4A: G vs F heads	Shraka	Thu, 28 October 2004 07:05
	Re: 4A: G vs F heads	da_horse	Thu, 28 October 2004 08:36
	Re: 4A: G vs F heads	justcallmefrank	Thu, 28 October 2004 08:45
	Re: 4A: G vs F heads	Shraka	Mon, 01 November 2004 03:10
	Re: 4A: G vs F heads	justcallmefrank	Mon, 01 November 2004 03:11
	Re: 4A: G vs F heads	Shraka	Mon, 01 November 2004 03:18
	Re: 4A: G vs F heads	86tt	Mon, 01 November 2004 14:15
	Re: 4A: G vs F heads	takai	Tue, 02 November 2004 07:41

Previous Topic:	T-series limo Q
Next Topic:	Anyone supercharged an ae92 or 93?

Powered by: FUDforum 2.3.8
Copyright ©2001-2003 Advanced Internet Designs Inc.