1986 Pontiac Sunbird GT (C18GET)

[Metro666]

Hey everybody.
My name is James,i am from Quebec Canada and i'm posting here for one of my friends that has an ultra rare 1986 Pontiac Sunbird GT hatchback with the Opel/Holden built C18GET.
Later version of the Pontiac Sunbird GT/SE has the C20GET engine.
We've read on multiple forums that this engine was shared with alot of other platforms (Opel/Holden/Vauxhaull/Daewoo)
And yesterday we went to a local scrapyard to compare engine blocs of Daewoo Nubira's/Leganza's/Chevy Optra's also and to our suprise the engine blocs look very very close to be identical to my friends '86 C18GET.
What he wants to do basically is take a later engine bloc and swap it into his Sunbird with th DOHC head and other stuff to make something that has good potential.

Can anybody help us out to confirm us if it's true that probably everything might be interchangable??
Thank you guys... i will post pictures of the Sunbird later on!!

[vinceMK6]

[gse_turbo]

Welcome to the forum. We look forward to seeing some pics of the project.

The engines are very interchangeable. The easiest thing to do is take a complete 16v engine and do the swap. It's not worth picking and choosing parts. The 16v engine will bolt directly to the trann already in the Sunbird.

There will be one issue, the power steering pump. The motor mount bracket from the sunbird will be used on the 16v engine but it will take the place of the power steering pump and A/C bracket.

There is a member here that has done a similar swap, it was a 16v into a Grand Am that had a C20GET. His name is 'Pontiac Jeff'. He'd be a good one to talk with about the fine details of the swap. He had a couple clever ideas for keeping the C20GET ECM with the 16v engine.

[Metro666]

Thank you very much for the info.
I guess my friends has no interess of putting back the power steering pump nor the A/C (which the compressor is seized btw)
I guess there will be some custom wiring to do but that's no issue for my friend in that case!
Will post up some pictures in a couple of minutes.

And again,thank you very much!

[gse_turbo]

Glad to be a help. I'm sure we are all looking forward to seeing a new projects in the members section.

[Metro666]

Here is the Facebook page of my friend's '86 GT.
Please like and share it to everybody!
https://www.facebook.com/home.php#!/pag ... 52?fref=ts
Hope you guys like it!
Will start posting pictures as the project starts off!
Thank you again!

[PrecisionBoost]

What he wants to do basically is take a later engine bloc and swap it into his Sunbird with th DOHC head and other stuff to make something that has good potential.

What are your goals for power ?

Is it an automatic or manual ?

What is your budget for the project ?

Given the 16V engines in North America are naturally aspirated (with less power than your C18GET ), it's likely that it will cost far less to simply increase the power output of the C18GET or convert to a C20GET

I have a C20GET and I've worked on a number of projects where C20GET's were installed in various vehicles ( check out project "super swift" for example )

If I had a budget of $2500 I would spend half of it on a nice new Garrett GT28RS Turbo ( which can be sold if the project doesn't work out )

The other half would be spent on a front mount intercooler, a 5th injector with electronic controler and a water/methanol injection kit.

300 horsepower is not out of the question, sure the 8V does not flow as well as the 16V, but that is why you have a turbo.

Sure the 16V might make 220whp on just 10 psi, where the 8V would require 15psi to do the same but who cares, it doesn't cost you anything to increase boost, your still getting the exact same quantity of air/fuel into the chamber.

In short, the 16V engine is a pain in the ass to convert to turbo.

You need a custom turbo exhaust manifold ( 8V and 16V are not compatible ),you need to buy a new turbo, you need to get all the adapters required to supply your turbo with oil (and coolant if T28 style used ), you need perhaps 40+ hrs of work on the wiring ( if you are experienced ), your factory 16V compression is too high so you have to change out pistons, then you have to worry about the rods and at very minimum replace the rod bolts, then you have to fabricate completely new intake piping and the list goes on and on.

It won't take long to drop $7,000 into the 16V engine setup ( unless you are a master fabricator and can make yourself custom parts )

Dollar for dollar the C18GET and C20GET will beat out the 16V for the same power levels.


The big question is in regards to the transmission or gearbox type, the TH125C automatic will only allow for marginal gains in power before it starts to slip.

I believe you would have the Getrag 282 5speed ( if it's a manual ) which can take some significant power, but a clutch upgrade will be required for anything significant.

Feel free to look at my GSiTurbo project car, it was designed like your Sunbird, I also had to go without power steering and eventually decided that was a really bad choice.

My Passport Optima is lighter than your friend's sunbird and although it was fun to drive without power steering at any speed over 4km/h it was a bitch to handle in the parking lots and I came very close to accidents on a number of occasions.

There are electric/hydraulic power steering units which could be used with the 16V, but my honest opinion is to spend the money on fixing up the C18GET or move to a C20GET.

Chris

[PrecisionBoost]

Just noticed the comment on facebook about looking for a manual to drop into the sunbird, if you do plan to do this I would suggest looking at a performance clutch/pressure plate so that you save yourselves headache in the future.

[Metro666]

Well... sorry to say this.
I just told my friend the recommandations that you guys told me. (He doesint speaks nor understands english)
And he is very discouraged about all the work it going to take him putting a 16 valves engine into his Sunbird.
So he is sending the Sunbird to the scrapyard

Thank you for you time guys i'm very sorry.

[vinceMK6]

[PrecisionBoost]

Shame to see a perfectly good car go to the scrap yard, there are lots of guys running 300-400hp with the 8V