Jet valves in G63B engine

Nov 27, 2004 3 Replies

Can anyone tell me whether the jet valves in a G63B engine (2.0l, 1988 Dodge Colt Vista) can be replaced without removing the rocker arm assembly? Apparently some of the Mitisbishi jet valve engines have enough play to slide the rocker arm sideways to get access to the screw-in jet valve assembly but I have not been able to determine whether that is true for the G63B. I'll be replacing the jet valves with plugs but have not yet had the valve cover off to see what is involved in the process.



While I'm asking questions, would a G64B 2.4l be a drop-in replacement for the smaller G63B? Are there other considerations?



TIA



KF


Its certainly easier to get them out with the rockers off.

Yes, 100%.

Some years ago I replaced the worn out 4G63 in my 89 Vista with rebuilt

4G64B from a Hyundai Sonata. Actually I did it twice, as the first 4G64 lasted 15 months before a %&*@## jet valve burned out and jammed, causing the rocker to break, which then caused a valve to drop into the cylinder. The piston came back up and stuck the valve back into the head, but not in the hole it came out of ....

I used the Sonata intake and injectors, and the Vista exhaust manifold (Sonata won't fit clear the radiator). The Sonata ECU is a direct, plug-in replacement, though I recall I switched the ECU board in the case so it would bolt in easier. Everything else is direct bolt up replacement. If your

88 has a carb rather than fuel injection, you'll have to do some extra wiring.

The 4G64 SOHC 8V is 2354cc (hence marketroids can call it a 2.4L) with a much longer stroke that provides lots of torque, but also limits the engine breathing to about 5500 rpm. If you are going to do a swap, you might consider the following:

a) swap the G63B SOHC 8v with a 4G63B DOHC 16v (Eagle Talon, 93 Sonata, Eagle 2000 GTX). Its a better engine and is more lively than the 4G64 SOHC

8v. In fact the 92 Sonata had the 2.4L 4G64, and the 93-95 had the 2.0L 4G63 DOHC and performed better. The DOHC will fit in the Vista. You'll have to sort out a new front pipe as the exhaust manifold flange is different. Likely a Talon front pipe can be adapted to fit.

b) if you really want 2.4L, then the 93-95 4G64 SOHC 16v (eg from a Summit wagon) will fit, its a better engine than the 4G64 SOHC 8v, and does not have the %#$@ jet valves. You will have to do some fiddling with intake parts, but the sensors are more or less the same, just in different packaging. PROBABLY, you can connect up the existing bits and it would work. I'm not sure if the ECU has the same connections and connectors as the 4G63. Its likely quite a bit more work than swapping the 4G64 SOHC 8v.

Whatever engine you choose, it would make sense to rebuild it as necessary before installation.

Stewart DIBBS

You will have to at least loosen the rocker shaft assembly anyway even if you slide the rocker over. Removing the shaft assembly is no big deal. Just put the tips of some latex gloves over the rocker ends so the lifters don't fall out.

Thanks, I like that suggestion. KF

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