Toyspeed.org.nz Message Board

by **mega4a** » Tue Apr 05, 2011 6:54 pm

got a project going. just wondering what ppl thought of a gze bottom end with a fe head?

by **iOnic** » Tue Apr 05, 2011 6:59 pm

What do you think of scoring a JZA80 and swapping the 2JZ out for a 4K?

If you really want to do anything put the 7AFE in there instead of the 4AFE.

by **AE82 FXGT** » Tue Apr 05, 2011 9:07 pm

^awesome reply.

to mega4a: WHY?

by **Rookie** » Tue Apr 05, 2011 9:08 pm

It depends on which 4AFE head you use, but if you use the late model one, it has the potential to be epic. They are the best 4A head by far with a little work. Only use the GZE bottom end if going turbo though.
Use the one with the inlet ports that look like this:

*Edit* I just read you build diary, confirm that the inlet port look like the picture above, and then go hard young grass hopper. Turbo is all about max CFM so I would get it ported, with bigger valves and double valve springs too.

by **CelicaGT8** » Tue Apr 05, 2011 9:32 pm

I was thinking he was out of money...

by **iOnic** » Tue Apr 05, 2011 11:03 pm

Rookie wrote:It depends on which 4AFE head you use, but if you use the late model one, it has the potential to be epic. They are the best 4A head by far with a little work.

Why are the FE heads so much better than the 16/20v GE heads?

OMG so shiny! · by **Dell'Orto** » Tue Apr 05, 2011 11:08 pm

Port angles look good, inlet looks like its quite straight. Theres no real reason you couldnt get good power from one, just no-one bothers when the wide angle heads are so cheap and readily available.

by **Rookie** » Tue Apr 05, 2011 11:33 pm

A couple of reasons, because the narrow included valve angle enables a better port shape, and the much larger cam buckets. Don't get me wrong they are not perfect by any stretch of the imagination.
Here is a pretty good pic comparing the different port designs between the 16v 4AGE, 4AFE, and a mid 90s Renault F1 head:

As you can probably see the 4AFE is light years ahead of the 16v, but still a long way from the F1. The narrow included valve angle means that the port can be a lot more upright, and as such allows a much more direct shot at the back of the valves, this is good for HP. As I said earlier they do need a bit of work, this is on the exhaust ports, they don't have the flow capability to keep up with the intakes standard but with a bit of work they can be fit for purpose.

The larger cam buckets enable you to reliably run a cam with much higher lift, this also aids HP. The reason it can is because the cam doesn't run off the edge and provide sideways loading on the bucket.

The downside is of course the lack of aftermarket following, and the scissor gear cam drive as this means that there would need to be some creative engineering go on to make the cam timing adjustable, but again not impossible.

HTH

PS here is a engine simulation I prepared for a race spec 4afe:

by **Rookie** » Tue Apr 05, 2011 11:34 pm

This guy bothered, made 248 hp at 9000 rpm

by **AE82 FXGT** » Wed Apr 06, 2011 12:21 am

huh, the f1 comparison sold me on the potential behind it.

I see that people get the 16/20 ge heads as they are readily available but surely so are fe heads?

by **KinLoud** » Wed Apr 06, 2011 2:38 am

My magic 4a/7a compression calculator says you will get 9.8 compression with gze pistons and 4afe head
Standard 4afe compression is 9.5 - Narrow included valve ange = small combustion chamber so the 4afe and 7afe pistons have quite a big dish.

Has the motor blown up? Just stick with common easy 4afe everything.

Looks like a 4agte I know of...
Can't quite tell as the pics don't show the whole car.
Who did you buy it off?

Ken

by **Mr Revhead** » Wed Apr 06, 2011 9:58 am

You've been reading too much of Mr Sherwoods stuff

Serious $$$ to get power from a 4afe.

by **tsoob** » Wed Apr 06, 2011 10:46 am

whats the comparison vs b/t 20v head tho?

by **mega4a** » Wed Apr 06, 2011 10:19 pm

AE82 FXGT wrote:^awesome reply.

to mega4a: WHY?

why not haha ive got lots of 4afe bits and its different? and my 4afe + turbo went hard on 8psi with stronger bottom end more boost could be even quicker..?

by **mega4a** » Wed Apr 06, 2011 10:33 pm

KinLoud wrote:My magic 4a/7a compression calculator says you will get 9.8 compression with gze pistons and 4afe head
Standard 4afe compression is 9.5 - Narrow included valve ange = small combustion chamber so the 4afe and 7afe pistons have quite a big dish.

Has the motor blown up? Just stick with common easy 4afe everything.

Looks like a 4agte I know of...
Can't quite tell as the pics don't show the whole car.
Who did you buy it off?

Ken

haha yeah the 4afe plus turbo was sounding like a suby bop bop bop at idle loosing compression most likely cracked ring. so since im currently suspended from driving for loss of traction. i decided to pull it apart as i did i found piston 1 and 4 ring lands were crack. so i have borght a 4agze ae101 bottom end and im going to rebuild it as these are well know for handling boost and since its 4a block and i have fe head with turbo mani etc.. i thought strong turbo 4afte? i thought the c.p would be lower since there dished pistons 4agze ones?

and nah man i built this all myself =] family car given to me.

by **Bazda** » Thu Apr 07, 2011 12:14 pm

I doubt a 20v conversion will be any more $ than trying to make a 4afe head get those flows.

if you stick on a 20v BT head you can easily achieve 250kw atw on pump gas shown by many people on the forums already.

by **mega4a** » Thu Apr 07, 2011 12:56 pm

Bazda wrote:I doubt a 20v conversion will be any more $ than trying to make a 4afe head get those flows.

if you stick on a 20v BT head you can easily achieve 250kw atw on pump gas shown by many people on the forums already.

http://www.pipeflowcalculations.com/ im sure a 20v head would flow more but if increase cfm on the fe head ill still make more. more CFM in my case = more turbo work, less motor base ability but still same hp in the end.

by **Bazda** » Thu Apr 07, 2011 1:34 pm

You know head work is not cheap.
Head work is $$$$$$ if you want it done right to get the results.

You can pick up a 2nd hand 20v head and throttles for under $500.
Wack that on, mod your flange on the ex mani and your away basically.

anyhow, your money to waste not mine

by **mega4a** » Thu Apr 07, 2011 2:24 pm

Bazda wrote:You know head work is not cheap.
Head work is $$$$$$ if you want it done right to get the results.

You can pick up a 2nd hand 20v head and throttles for under $500.
Wack that on, mod your flange on the ex mani and your away basically.

anyhow, your money to waste not mine

but why would i need head work? the std head will work well with boost application im not going n/a high reving? just forcing more pressure through the head. maybe a custom intake since the stardard one is so restictve and thats it and i can weld up myself cheap.

by **h8wrxs** » Thu Apr 07, 2011 2:25 pm

complete blacktop motors inc throttles occasionally come up cheap, i bought one for $200 about a year ago... shouldnt have given that away

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