4g61t.org

Sorry to start a next thread, but the sight would not allow me to add on to the previous one. I have a stock 4G61T block and head and I was wondering how a DSM intake manifold and throttle body would work on it. Will it allow much better flow, or will it cause excessive lag? I don't know if the intake runners are too large for the intake ports on the 1.6 head to be an effective mod.

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Drive fast, speed turns me on!

Not a good idea putting a 2.0 intake manifold on a 1.6 head. The intake ports on the 2.0 are much larger therefore the air coming from the intake will run into seriously smaller ports on the head. Not a good thing.

See the pics in the thread below which shows the difference between the two. I got away with it because I have a 1.8 head which has the same size ports as a 2.0.

See here... http://www.4g61t.com/forum/viewtopic.php?t=8607

You can put a 2.0 TB on your 1.6 intake manifold, you just have to port out the inlet of the intake to match up with the larger throttle body. Many people have done this.

Heck, for that matter you can put a 2.0 intake manifold on a 1.6 head as long as you port the intake runners on the head.

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Trent
'89 Colt GT
Member #1

wow, you 61t guys are getting screwed on the intake side, i bet your exhaust ports are even smaller than the 2.0 as well...

i just got my head back from the shop friday (complete rebuild and hks 264's) and can definately say that the 1g 2.0 head intake ports are hooked up but the exhaust ports need help.. has anyone done thier own port work on thier heads? i was thinking of trying it on the exhaust side of my head but i dont want to screw it up...

Well I would not say that a 1.6L DOHC guys are getting screwed. What I would say is that the head design fits the engine size. A 1.6L head is designed for the volumetric effiency of what the motor can handle. Look at the bore size difference between a 1.6 and a 2.0.

1.6 is 82.3mm bore
2.0 is 85mm bore

An additional 2.7mm diameter in size alot of difference when your talking volume of air with in the combustion area. So a 2.0 can take advantage of larger runners in the intake, and larger exhaust runners in the exhaust manifold.

Just remember air in = air out, more air in = more air out. If your motor is designed correctly for your use then it will perform as you want it to. Example: Drag car uses lots of torque to launch and needs a ton of air ont he topside to build high MPH passes. So a 2.4L 4G64 has a standard bore of 86.5mm and a stroke of 100mm. Most people over bore the motor to 87mm for more volume of air to enter into the combustion chamber. The 2.4L motor is a good setup to build the max amount of torque to get the car going as quick as possible then produce enough Horse Power to keep the car going as fast as possible. Long stroke Big Bore.

What alot of people over look when buying 4G61T motors from JDM importers is what head is on the motor. Usually you will find 1.8L heads, which is very close to the 2.0. Thus far I have researched parts catalogs and found that the 1.8L head and the 2.0 head use the same gaskets, same intake and exhaust valves. Oh and also the 1.6L uses the same intake and exhaust valve as the 2.0 and 1.8.

A 1.8L head in effect is the same as bolting on a 2.0L head while keeping the 1.6L intake manifold and TB. This is why some people want to know why there car does not respond the same when they switch to TDO5-14B or TDO5-16G turbos. Many complain about the turbo taking too long to respond. Well in reality what Mitsubishi did was upgrade the 1.6L motor by giving it a 1.8L head which flows more with 1.6L intake manifold and 1.6L exhaust manifold a TDO4-13G turbo with a 5cm exhaust housing on the car with more boost. This in turn allowed the 1.6L motor with 1.8 head to flow more and have a higher power band at the higher rpms, instead of having the power drop off when using the 1.6L head.

Hope this helps because I went to post the 1.8L info to the already archived thread to help complete the search. Oh well!!