4AGE 20 Valve Silver top V Black top

**KE20_4AGTE** · 06-09-2010, 03:27 PM

Has anyone ever sat a 4AGE 20V Silvertop head next to a Blacktop head and compaired the differences as researching on the net there are so many conflicting comments.

Are the exh ports larger on a black top?

Are the combuction chambers different?

Or did the blacktops make more power due to the larger cams, throttle bodies & higher compression ratio?

I'm building a 4AGTE and have a Silver top 20V head in the shed and I don't know weather to use this or my 16V head that is fully ported with 1mm oversize SS valves, HKS springs & HKS 272 cams

Any help would be great, I look forward to your comments

Cheers
Josh

**AdrianS** · 06-09-2010, 09:01 PM

Search around a bit - the truth is out there. The chambers are quite different, but I don't know about port sizes.
Internet gossip seems to concur that a built 16v will give more peak power than a stock 20v.

**Casey-G** · 06-09-2010, 09:12 PM

As much as it will depend on exactly how far you want to go with the engine, the blacktop flows better and is superior to the silvertop head. A guy on twincam.au who goes by the user name "bazda" races a 7agte levin GTZ with a BT head, he had most of the 4a heads bench flowed with and without modifications i believe prior to building his engine and the blacktop came out in front by a fair margin from what i have read.

If you sign up over there (not sure he is on here) and send him a PM im sure he will be more than happy to fill you in on the nitty gritty details.

**foamy** · 06-09-2010, 09:44 PM

Depends how much power your chasing? If you want every single last hp you would end up having the head ported and it probably wouldn't matter which one you started with (unless your doing it on the cheapo).
http://billzilla.org/4agmods3.htm
If you want to keep a nice squish area? (maybe billzilla can lean in here if he's reading this).

**Dangerous Beans** · 07-09-2010, 10:33 AM

Originally Posted by foamy

Depends how much power your chasing? If you want every single last hp you would end up having the head ported and it probably wouldn't matter which one you started with (unless your doing it on the cheapo).

I disagree. If you are going to port the head you would want to start with the smaller ones. If you start with a big port, then the smallest you can easily have the intake is the stock bigport size, but with a small port you can take it out to pretty much the bigport size if you want to. It is more work, but gives you more options.

As for KE20_4agte's question, I think you would be better off with a silver top over a black top. From the info on bilzilla's site, the silver top looks to have a better combustion chamber, and the exhaust ports could be opened up pretty easily.
The best option is just to use the 16v head you have, that way you don't have to do all the work again.

**trdee** · 07-09-2010, 11:15 AM

Originally Posted by Dangerous Beans

The best option is just to use the 16v head you have, that way you don't have to do all the work again.

I agree. you already have a worked head there. Just use that, unless you have money to blow.

One thing I've always wondered, in big boost applications is the extra valve in the 20v head still a benefit? I remember reading somewhere that it can be detrimental due to greatly reduced squish area over a 16v or somesuch

**foamy** · 07-09-2010, 12:13 PM

Originally Posted by Dangerous Beans

I disagree. If you are going to port the head you would want to start with the smaller ones. If you start with a big port, then the smallest you can easily have the intake is the stock bigport size, but with a small port you can take it out to pretty much the bigport size if you want to. It is more work, but gives you more options.

As for KE20_4agte's question, I think you would be better off with a silver top over a black top. From the info on bilzilla's site, the silver top looks to have a better combustion chamber, and the exhaust ports could be opened up pretty easily.
The best option is just to use the 16v head you have, that way you don't have to do all the work again.

I figured you would want the bigger ones if you planned to fit oversized valves?

**KE20_4AGTE** · 07-09-2010, 01:46 PM

Guys
thanks for all the good info and opinions you are all very helpfull..
I'm chasing the sort of power the guys in europe are enjoying 500+ RWHP, I thought about going the 7A option but I like the underdog 4A's strength and the fact I can build it to rev to 9000+ rpm.
Keep your opinions comming thats what I like about this forum
Cheers
Josh

**Casey-G** · 07-09-2010, 01:58 PM

Blacktop + ported + OS valves + big cams and a massif turbo around the gt30 region.

A guy in NZ made 360kW on a stock gze bottom end with a blacktop head + big boost around 32psi

http://www.toyotanation.com/forum/sh...d.php?t=289922

**trdee** · 07-09-2010, 01:58 PM

Originally Posted by KE20_4AGTE

I'm chasing the sort of power the guys in europe are enjoying 500+ RWHP

good luck with that bro

**foamy** · 07-09-2010, 02:14 PM

Not to dampen your spirits, but 500whp isn't a cheap exercise...is there any reason you need to get it from a 4A and not something with a larger displacement?

**KE20_4AGTE** · 07-09-2010, 03:06 PM

Casey-G thanks for the info I currently have a HKS GT3240 but am thinking of running a TO4Z if I need to.. That power curve looks good for such a little engine

**KE20_4AGTE** · 07-09-2010, 03:12 PM

Foamy I know what you mean but it would be nice to have someone in oz to do it. I know the "Backyarder" AE82 has made 500FWKW with Nos & methonol so it is possible.
I also have a NX kit for the car and will be running E85 so I really want to lean on it to see what I can achieve.
i have only bee thinking about the 20V as I wasn't sure if it might have has a better power band on the 4A
As for the larger displacement I looked at a 7A but I didn't like the block and crank compared to the 4A
My engine builder has helped me set the bottem end up for 35+ psi
Thanks for all the suggestions again this info is priceless

**Cuzzo** · 07-09-2010, 03:23 PM

subscribing for possible LOLs.

Please prove us wrong but do you have 30-40K to spend on this build?

**KE20_4AGTE** · 07-09-2010, 03:56 PM

Originally Posted by Cuzzo

subscribing for possible LOLs.

Please prove us wrong but do you have 30-40K to spend on this build?

Hey Cuzzo glad to see I could make your day with a good LOL but I thought this forum was welcom to people with all kinds of budgets not just people on very tight budgets..

As for proving it theres no need as I have already put more than enough into my toys over the years and its my way of having alittle fun and I will keep doing so, I'm just here to chat with likeminded people on this forum

Thread: 4AGE 20 Valve Silver top V Black top

Thread Tools