1800 SOHC Carbs?

[Pombellett]

Hi guys...I need your help.

What have we got here?

http://www.ebay.co.uk/itm/171574726675

I thought it would be unlikely Chev/Isuzu would fit twin carbs to their pick up, but am I wrong?

I hooked this pic from an earlier thread....and this is a manifold for an 1800 SOHC engine.

1800cc_OHC_Carb-manifold.jpg (115.2 KiB) Viewed 43124 times

And you can see differences on the manifold to head surfaces compared to the E Bay pair.

Any ideas?

[Asroc66]

Hi
Yes indeed this is a manifold from 1800SOHC motor fitted to Bellett 1800 GT 1971-72 and early Chevy Luv's in USA
The carbies you require I think are
Hitachi HJE38W - 38mm fitted to ealy Datsun 240Z motors as they are 4 bolt not 2 bolt
Cheers
J

[PR95]

SHHSSHH Don't mention the Cricket...........

[Glenn]

This might help comparisons, (looks pretty much same to me )

....I pulled out the 1800 SOHC manifold to take picture of other side.

glenn

[Pombellett]

Thanks J and thanks Glen.....that's a big help.....although, now looking at all these pictures and looking more closely at my own carbs from my 1600 SOHC, the manifolds look pretty much the same. This is mine.

FullSizeRender (1).jpg (1.87 MiB) Viewed 43074 times

The only difference I can see is the lower outside corners have the pointy flanges on mine, but not on the others.
So my question is.....if I were to get hold of an 1800 SOHC engine, will my 1600 manifold and carbs fit it? It's beginning to look feasible is it not?

Incidentally the E Bay carbs/manifold look a bit suspect to me, but I think that's because it looks like they are upside down on the manifold. Here's the pic.....

twin2.jpg (83.96 KiB) Viewed 43074 times

Oh and...what cricket was that PR95? I've, err, not seen any cricket for ages. Looking forward to taking back the Ashes this summer though....err...or am I?

[Asroc66]

Hi Again
I have been confused until I realised you are talking about a G160OHC not OHV engine
We didn't get the 1600 OHC in Aus unless I am mistaken?
The 1600OHV engines which came to Aus had twin Hitachis had 2 bolt carbies (bolts at 12 and 6 o'clock unlike Datsuns which were offset)
The 1800OHV engines which were destined for JDM and Europe had the 4 bolt carby pattern as shown in your pictures.
Below is a picture of the G160OHC engine we never got.

The 1600OHC engine looks like it has a different bottom end to the 1800OHC but similar Head (Not totally sure though as have never actually seen a G160ss with my own eyes just the G180ss which has a taller block). If true then the 1600OHC has 75mm rods and 82mm pistons (1584cc) while the 1800OHC should has 82mm rods and 84mm pistons (1817cc). If you can find a 1800OHC engine, forged Conrods and pistons are readily available so why not go all the way, regrind cam while you are about it and hey presto - very nice G180ss.

Anyway, having said all that it is highly likely then that your manifold should fit the G180OHC and yes the carbies in the picture are on upsidedown - marvellous
Hope this help
Cheers
J

[Asroc66]

G1800 OHC engine
Block looks different
Note the orientation of the oil filter + two bolt points at front of block on the 1800OHC.
Head looks a little different also. Note the oil gallery between cylinders 2 & 3! It is a protruberance on the 1800OHC engine vs the 1600OHC.
Cheers
J

[Glenn]

I agree, i would think the manifolds are interchangeable from 1600 to 1800 SOHC.

[Glenn]

Hi Again
I have been confused until I realised you are talking about a G160OHC not OHV engine
We didn't get the 1600 OHC in Aus unless I am mistaken?
The 1600OHV engines which came to Aus had twin Hitachis had 2 bolt carbies (bolts at 12 and 6 o'clock unlike Datsuns which were offset)
The 1800OHV engines which were destined for JDM and Europe had the 4 bolt carby pattern as shown in your pictures.
Below is a picture of the G160OHC engine we never got.

The 1600OHC engine looks like it has a different bottom end to the 1800OHC but similar Head (Not totally sure though as have never actually seen a G160ss with my own eyes just the G180ss which has a taller block). If true then the 1600OHC has 75mm rods and 82mm pistons (1584cc) while the 1800OHC should has 82mm rods and 84mm pistons (1817cc). If you can find a 1800OHC engine, forged Conrods and pistons are readily available so why not go all the way, regrind cam while you are about it and hey presto - very nice G180ss.

Anyway, having said all that it is highly likely then that your manifold should fit the G180OHC and yes the carbies in the picture are on upsidedown - marvellous
Hope this help
Cheers
J

that particular 1600SOHC seems to be based more on a OHV block.... the area where the engine number is stamped for example. Maybe an earlier iteration. ..... Like all things Bellett though, there always seem to be subtle changes along the way.
I would imagine though, that generally speaking, the heads would be interchangeable. My 1800ss also has extra bosses on the block for mounting air con too.

But I think Mark is more interested in getting a capacity increase, so a move to 1800 SOHC would be a logical move (if racing legal)??
And possibly can use his existing head which I assume has had lots of work done on it, on the bigger block.

[Glenn]

what dual master cylinder are you using there, J.

I see you have an oil leak also in same place as my 1800SOHC..... pretty common I think. And annoying !

[Asroc66]

Hi Glenn
This was how Asroc arrived from Perth WA with the G180s motor
The leak was due to a pinched 'O-ring'
This engine is now 'refreshed' and bolted to an engine frame under my house waiting for a new home - perhaps a GT one day.
Asroc now has the Turbo G161 hybrid

The dual master cylinder is from a Datsun 120Y

Cheers
J

[Glenn]

Hi Glenn
This was how Asroc arrived from Perth WA with the G180s motor
The leak was due to a pinched 'O-ring'
This engine is now 'refreshed' and bolted to an engine frame under my house waiting for a new home - perhaps a GT one day.
Asroc now has the Turbo G161 hybrid

The dual master cylinder is from a Datsun 120Y

Cheers
J

How refreshed is it ? I have many parts for a rebuild, but only LUV parts (lower CR pistons for example)
Did you do a total rebuild all new, or hone and new rings, perhaps?

OK on the Master too, thanks

glenn

[Asroc66]

Hi Glenn
Rebuild was undertaken by my race mechanic
Bottom end bearings were checked for clearance and retained.
Light hone and re-ringed origional pistons
Balance
Head ported and polished
Cam ground aggressively
New timing gear and gaskets throughout - Sourced from USA

I have an origional set of 30' over flat top pistons but did not require them

Nothing wrong with Luv parts otherwise
Cheers
JD

[Glenn]

Hi Glenn
Rebuild was undertaken by my race mechanic
Bottom end bearings were checked for clearance and retained.
Light hone and re-ringed origional pistons
Balance
Head ported and polished
Cam ground aggressively
New timing gear and gaskets throughout - Sourced from USA

I have an origional set of 30' over flat top pistons but did not require them

Nothing wrong with Luv parts otherwise
Cheers
JD

thanks, yes that's the only issue, In have set of LUV pistons. But better to have something rather than nothing i guess.

here's a pic of the original pistons and a better pic of the block also....(borrowed from web)

[Asroc66]

Standard compression for G180OHC is 9.7:1 which is quite high
If you overbore this will rise so a set of flat tops would be appropriate and are available
Cheers
J

[Glenn]

Standard compression for G180OHC is 9.7:1 which is quite high
If you overbore this will rise so a set of flat tops would be appropriate and are available
Cheers
J

I built my GT engine with 9.6:1

I have +30 i think flat top LUV pistons here.

[Asroc66]

Rudimentary calculations
Using 0.75mm oversized flat top pistons will give u approx 9.5:1 compression
Which is the butter zone
Cheers
J

[Glenn]

Rudimentary calculations
Using 0.75mm oversized flat top pistons will give u approx 9.5:1 compression
Which is the butter zone
Cheers
J

sounds perfect......

[PR95]

I have a 1600 SOHC motor in pieces. in my shed.

[Pombellett]

"But I think Mark is more interested in getting a capacity increase"..............aah, you didn't come up the river on a bike Glen, did you? :

The early LUV engines seem quite commonplace in the States, and not overly expensive....shipping to the UK is getting cheaper by the day (as we cease to manufacture everything and import it instead....but that's another topic)

We'll probably re model the 1800 head, as my friends in mainland Europe reckon it'll have bigger valves ( they also reckon the 1800 has a considerable capacity for boring out)

It's nice to know that the 1600 manifold and carbs (and therefore exhaust manifold) should fit
....all of this we can kind of, just about, sort of, stay within the rather loose regs we have for Rolie's lot.
Thanks for your continued help J and Glen....I'm sure I'll be tapping you up for more, when the engines arrive from across the pond.

In the meantime we've just started work on getting the 1600 quick and reliable again, and I'll continue to post our progress on the Rolie thread for those who are still interested.