Series I or II

[paddyj]

How do I know if I have a series one or a series two engine? It's a VN V6 executive 1991. I'm getting a new thermostat and apparently the gasket is different depending on the series.

Thanks,
Paddy

[stocky]

it would probably be a series 2 engine. do you have a photo of your engine bay?

[paddyj]

Thanks,
Don't have a picture now but I can post one in the morning. Is there some way I can tell by just looking at the engine?

Paddy

[geta]

if the hose from the top of the radiator goes to the front of your engine, its series 2. Being 1991, it should be series 2 unless someones dropped a series 1 engine in it later :S

-dave

[mouce]

If the fuel rails are black and round then it's a series 1, if they are large chunky and silver/grey then it's s2

[kowan]

If it has a 8 bolt hole in the flex plate its a S2
If it has 6 bolt holes S1

I would't pull the gearbox off to look though LOL

[fitzy2005]

How do I know if I have a series one or a series two engine? It's a VN V6 executive 1991. I'm getting a new thermostat and apparently the gasket is different depending on the series.

Thanks,
Paddy

see if some body can take you down to get ur thermostat gasket, that way take ur old one

[fitzy2005]

gaskets dont cost, so buy two if worse coems to worse

[paddyj]

Ok the fuel rails are black and round. When standing in front of the car, the top radiator hose goes down the left side of the engine and into the back, lower radiator hose goes straight in to water pump.

What's a flex plate?

Yeah I got a series 2 gasket a lunch time, it was only 95 cents so I'll just get a series 1 gasket tomorrow and compare them when I do the change. I didn't realise they were so cheap because I was quoted 9bucks over the phone.

Is there any power/performance difference between I and II, why did they release another series?

Paddy

[GroopA]

If the radiator hose is going around to the back of the engine, you got a series 1.
Prick of a location to chuck the thermostat. never could figure out how to get to it without ripping off the throttle body inlet manifold?

[mouce]

^^^You DO have to take the t/b off to do the thermostat in the S1 engine, AND the 90 degree elbow to the inlet manifold.

As for whey they released a second version of the Buick V6...there's a lot of reasons: the idle in the s1 was rougher than the s2 (they made it a bit smoother), a few bits got moved (thermostat is in a much nicer place on the s2 engine). One of the reasons that they needed to 'retune' the engine is because the torque delivery of the s1 engine is VERY sudden, it was actually bad enough that there were old people who were unintentially looping it in the wet because the car broke traction.

The Buick V6 was actually taken from a car in the US where it was used in an east-west configuration. GMHA took the engine dropped it in as a north-south engine and never retested the power output. In the E-W setup it was measured as having 127kW (and a tonne of torque low in the rev range). GMHA made a few modifications to a few bits and pieces when it was rotated 90 degrees and quite possibly the power output went up, they removed the Manifold Air Flow sensor and replaced it with a Manifold Air Pressure sensor (less disturbance to the airflow, much better induction). The stock exhaust manifolds are at just the right length to act as kinda weak extractors which in turn helps power production...

So the S1 engine was deemed to be a bit 'harsh' for the general motoring population (damn popular with younger drivers though ), so they sort of tamed it a bit.

That and the VNV6 S1 engine is more than capable of keeping up with (or beating) the VN V8 up to street legal speeds.

[paddyj]

Thanks for the great info! I'm glad I have an S1 now ha ha although I'm having second thoughts about changing the thermostat.

I have to change my radiator coz it's got a hole in it so I'm flushing the cooling system as well while I'm at it. Probably don't even need to change the thermostat just thought I'd follow the guide in the how-to section but maybe I'll just skip those steps!

Paddy

[lilredwagon]

You might be investing in a thermostat housing as well - the S1 housings rot themselves into the manifold and don't want to come out without large amounts of of brute force and ignorance which tends to leave the end of the housing (below the 'O' ring) behind in the manifold.
Lots of fun to be had by all, if you don't want to score the manifold where the 'O' ring seals!

[getafix]

weird, i thought nov '90 was the S2 changeover.. although i guess you might have a '90 build, but first registered in '91.. either way, yer series 1 it is. Thermostat isnt so bad, just be careful. Its a good opportunity to give the throttlebody a good clean, or change it to a V8 one.

-dave

[SlowVac]

Nov 90 was the series 2 changeover and some dealers at that time had some old stock left in the car yard and sold them in 91 because either they had too much old stock or slow period in not selling many cars.
A friend has a early 91 Vn exec and it's has the series 1 engine and the build plate said oct 90.
My father bought our VN in late december 90 and it had the series 2 motor the built plate had nov 90.

Just be patient in changing the thermostat.

[mouce]

@getafix, not a bad idea using this as an excuse to change to a V8 t/b. Though I have heard (have not yet tested though) that a t/b from an XF falcon will bolt straight up. Now I know that it's out of a ford and all, but 67mm t/b, and I'm guessing that it would be cheaper than a holden V8 one.

I'm going to look into it.

Oh, while you're changing the thermostat, take a few pics of it to show us how it's done.

[paddyj]

What would be the benefit of a V8 throtle body? More power?

No worries I'll take some pics when I do it, still waiting for my radiator to be delivered so won't be doing anything till I get that.

Will defo clean the throttle body while I have it off, any tips for cleaning it? Going to flush the cooling system as well before I take out the old radiator.

Paddy

[kowan]

paddyj a Flex plate, drive plate, flywheel, all the same thing.

a S1 thermostat housing is a proper back breaking,skinned knuckling SOB bastard (must I say anymore) job if it is old and moldy.

There!!!....I`m happy....I didn't swear much.

[mouce]

Easiest way to clean the t/b is to get a can of carby cleaner and a rag. Soak the rag with the carby cleaner, and start scrubbing.

Take the IACV off and give that a good clean up too. Try not to get too much on the TPS otherwise it could die, which would cause problems.

Get the insides of your t/b nice and bright and clean and you're all good to bolt it back up.

[paddyj]

Thanks for the tips, got a new thermostat housing at the weekend so that should make the change a bit easier. Series I uses a seal and not a gasket, just in case any one is wondering!

[slimman]

The best way to clean the t/b is with "CRC Carby Clean" and a old (or new) toothbrush, if you want you can bolt off the sensors (and all plastic bits) and soak it in kero for a bit then scrub the living sh!t out of it, no doubt you will notice a smoother idle and response. and make sure under any circumstances you DONT use sandpaper, i know someone you did it and had to get another t/b coz' it was rooted

[paddyj]

Thanks for the tips, so what will I be scrubbing off? Thought it was just air that went through it?

Paddy

[paddyj]

Ok changed the thermostat yesterday, here are some pics. If anyone is doing this make sure the water outlet hose in is good condition and not leaking before you put things back together, mine was spraying coolant and I had to dismantle everything again today! Old housing was completely screwed, looked like it was the original one, had to bask it out with a hammer!

[mouce]

That set of photos is really handy. Thanks for posting those. Now that it's all back together is it all running nicely?

[silver_bullet]

sweet thread, great pics, thanks.