4g61t.org

Looking to put a head onto my 2.0L motor. Wanna bump up the compression a bit as well. Been reading into the 4G67 head. Looks good, BUT....it's got the big 1G intake ports. I'm planning on running an EVO3 intake manifold, and the 4G67 head would negate that.

Which route would yield better results at all rpms? 4G67 head with 1G intake manifold, or a 4G61 with an EVO3 intake manifold? From what I understand, the 4G61 ports are slightly smaller, but nothing a small port job couldn't fix. Or, a standard 2G head with the EVO3 manifold? I really like the idea of the smaller combustion chambers of the 4G61/4G67 heads increasing compression (I'll be running E85) , as I want the most power down low (going on an auto car. need to get up on the converter quick. Using a Holset HY35). But not really thrilled of the idea of using big ports on the 4G67 and wasting the EVO3 manifold.

Looking for some opinions of guys that have done this before. Need to make a decision pretty quick.

I've never really heard of anyone attempting to install a 4G61 head on a 2.0 bottom end. Usually it's the other way around. I'm not sure what the 4G61 combustion chambers will do to the compression ratio on a 2.0L bottom-end. Do you know what the CC volume is on the 1.6 head? Is it the same as the 4G67? If I were you, I'd make my life easy and just run a 2g head, that way you can run the EVO 3 intake manifold without any issues.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

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The 4G61 and 4G67 head bumps up compression about half a point. So, for example, stock 1G bottom end goes from 7.8:1, to 8.3:1. 1.6L heads have 43cc combustion chambers, same as the 4G67. Life can be easy if the 1.6L works. I get the higher compression (which I don't get with the 2G head) as well as the smaller ports.

The only potential issue I see with the 4g61 head is the bore size. It may not even matter, but I know the bore on a 4g61 is like 82.3mm or something like that. I'm pretty sure the exhaust ports are identical to a 1.8 or 2.0 head, just the smaller intake ports, but I don't know if the intake ports are the same size as a 2g head.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

Check out this thread here, as this is what I have gathered from all over. Some strange large intake and small exhaust port combination heads, but 4g61 heads have small ports in and out. The reason for choosing the 4g67 head, is bigger 1G 4g63 sized ports in and out. In the case of our post's author, he would like small intake ports for velocity and larger exhaust ports?
http://www.4g61t.org/forum/viewtopic.php?f=2&t=14041

I think higher velocity is some of the mentality. A lot of people just really like the EVO 3 intake manifold. They are pretty nice. You have to run a smaller-port head to use one. The 2g DSM heads have a higher intake floor which improves airflow to the intake valves, but stock-for-stock they aren't really any better...the real improvement comes when you port them out more.

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91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

My 1.6 exhaust ports looked exactly the same size as my fp manifold, and I used a stock 4g63t gasket on them.
Leads me to believe the exhaust ports on the 1.6's are the same as 2.0's.

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4g61t.org
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You would be misinformed with that statement. Yes, the EVO3 intake is nice. However, the 2G/EVO head design is far superior to the 1G design. If you port out a 2G head on the intake side to match a 1G intake manifold, you are effectively negating the reason why they are better. There is a decent size thread on DSMLink forums as to why the 2G head is better than the 1G. They didn't make the EVO head based on the 1G design for a reason.

That makes sense. I wasn't really sure what the deal was with that. I would never suggest porting a 2g intake port to match a 1g intake port, but there's a lot more room to work with deeper inside the port than a 1g head, isn't there? I think the combustion chambers are a better design as well.

_________________
91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

Posted some of a members old pictures back into existence as the links had gone down.

http://www.4g61t.org/forum/viewtopic.ph ... 91#p264091

Realise this is 4g61 to 4g63 comparison mostly, but it give a visual in some cases. Wish I had more definitive stuff to post at this point.

Yea I herd the 2g head swap is the way to go but keep the 1g cams or go bigger.

heres my question i've got a 1.6t and have access to a 4g67 head, is it worth while to swap to the 67 head? If so which head gasket would i use? And would all my stock parts bolt right up, i need to do a little more research but, free parts are free parts specially if theyll help out with hp gains.

No.

_________________
91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus

So its not worth doing at all?

I wouldn't bother with it. The 4g67 head isn't really an upgrade for the 4g61 bottom-end, it's only an ugprade for the 4g63 bottom-end, and even then it isn't really much of an upgrade at all, you just get a tiny bump in compression.

_________________
91 GSX - 511fwhp and 352 lb/ft 25psi 110 octane, 7.68 @ 95.9mph 1/8th 21psi 91 octane, 11.93 @ 112.9mph, 117.7mph best trap speed, 20psi 91 octane
98 Volvo S70 T5 - DD

http://www.facebook.com/captaintonus