Hello everyone
I have a friend who has a small machine shop here in South Africa. He's got a 1600 Bellet - not running because the head has been skimmed too much, and he needs to know the stock head thickness, so he can make a plate to retore it? I would be very very grateful for any information about Isuzu Bellet heads
many thanks
Al
Karoo, South Africa

On the JNC forum, your question says "1976 Isuzu Bellet 1500 sport sedan" and "they say it will do 120 mph - pretty fast for an 'old' 1500 motor".

Some of the information is confusing.

If it is a 1976, it would be a Gemini or Bellett-Gemini, the later model car with the G161Z engine.
If it was made before 1975 and is a Bellett with a 1600 engine, it could be the OHV G160 (G161?) engine, OHC G161S engine, or DOHC G161W engine.
If it is 1500, it would be the G150 engine.
But most of those engines would not take the car up to 120 MPH.

I'm not sure if the head and block specifications are written down anywhere for the single cam engines, and any written text about the DOHC engine would be in Japanese.

You might have to work backwards from what you have, calculating the bore and stroke, the dome of the piston, how much capacity is left in the combustion chamber, and then what is missing based on the compression ratio.

thankyou for the reply. We went back and looked again - it's a G161 motor! I'm assuming G161Z? The capacity is unknown, because it appears to have been extensively bored/skimmed. Has only two valves per cylinder. The search for info continues...

I may have figured out the mystery.

The Gemini was introduced as the "Bellett-Gemini" in 1974. It's the car after the Bellett. Most people are going to call it a Gemini.

It had the G161Z engine. It's rounded up to 1.6 liter displacement. Actual displacement would be 1.5XX.

The only book I have that comes close to that one is a 1976 Buick-Opel-Kadett shop manual, but those apparently came with the 1.8 liter engine.

Bore and stroke might be found with a creative web search and looking for pistons or specifications for 1974-1976 Isuzu Gemini/Holden Gemini.

Deck height may or may not be in a shop manual, they seem to omit some specifications in some of the books.

Hi Zed,
Is the head from a ohv, a sohv or a dohv engine? Does it have 1 or 2 carbs?

Ouch. The DOHC and SOHC both have two valves per cylinder. I completely missed that and took two valves to mean SOHC.

We could really do with some visual aids here. A picture of the car and a picture of the top of hte engine would clear up a lot of confusion.