Having problems finding a head for a 86 mighty max 2.0

[dwittig33]

Lots out there for a 2.6, but I am unable to find for the 2.0. Just to make sure, I do have a plastic timing belt cover which would indicate I do have a 2.0 correct? Any ideas where I can find one? Thanks

[SubGothius]

First-gen trucks with a 2.0L could be either a 4G52 (Astron 4G5* family) with a timing chain or a 4G63/G63B (Sirius 4G6* family) with a timing belt. AFAICT from specs in the Haynes manual, the -B variants (Sirius G63B and Astron G54B) seem to indicate a head with jet valves, so you might try broadening your search by looking for both G63B and 4G63 engines.

Clearwater has these 4G63 heads, not sure if it would be suitable, maybe someone else here can confirm:
https://www.cylinder-heads.com/produ...e-cast-ch124n/

[dwittig33]

thank you for your reply. I'll look into that.

[dwittig33]

http://www.mightyram50.net/vbulletin...th-a-4G63-head

according to this thread if i'm understanding correctly, it looks like i'd have to switch to injection if i used a 4G63 head

[xboxrox]

dwittig33

C/L firewall metal label: the engine type is stamped into the metal... What is your engine..?

[dash]

plastic timing cover sounds 'Sirrus' to me. I'd contact clearwater. I've seen the same 2.0 sohc in forklifts as well
the thread you posted is about putting a DOHC on a truck 2.0 block. SOHC replacement won't require fuel injection

[dwittig33]

Good morning, so I did find another head online from a parts shop. there's a couple differences I wanted to ask you guys about. First off, the new head has oblong combustion chamber faces... whereas the old has perfectly round. And then there is a second port (threaded hole) near the plug hole. I'm not sure what that does, but the new one has plugs in it and the old has what appears to be a jetted fitting. Any thoughts to whether i should install this or send it back? Thank you.

[dwittig33]

G63B.

[dwittig33]

also the original had cam bearings, the new one looks like it fits perfectly fine without bearings... I'm reading that it may not need them? That sounds like a bad idea but what do you guys think?

[SubGothius]

G63B would have been a jet-valve head, so those threaded fittings in the old head were for the jet-valve inserts. I'm not sure what's up with those smaller plugged holes in the 4G63 (non-jet-valve) new head, might be a small pre-combustion chamber, or maybe the heads are all made with pilot holes they'd drill out for jet-valve inserts or plug otherwise.

Oblong combustion chambers may be shaped for better combustion and/or breathing, and prolly has less volume than the round chamber, which would get you a slight compression boost; just make sure they're fully enclosed within your head gasket cylinder rings.

In general, many OHC engine designs don't use separate/replaceable bearing shells for the cams, as the head material itself can be sufficient to act as a bearing journal. Cam bearings don't suffer the kinds of shock and pressure that crank/conrod bearings do, so Mitsu may have concluded cam shells weren't necessary and/or improved the alloy formula for later head revisions to eliminate shells for the cam bearings.