quite a few Q's

Mr_Efficiency · Post by **Mr_Efficiency** » Sun Dec 18, 2005 4:06 am

I'm new here so sorry if I ask any questions that are constantly repeated here, I searched around the site for while and didnt see what I'm looking for thus bringing me to my post......
I have a 89 sunbird and as far as I know the DOHC 16v (97+) head from teh daewoo legenza and nibura is a very similar casting to the C20LET and C20XE heads in teh UK, and I know that head will bolt onto a 2.0 sunbird as they share the same block.
I plan to pretty much build a C20LET (or similar) with parts from north america, my question is what do these motors have for internals? are teh pistons or anything forged? the pistons in teh sunbird are and I'd like to keep forged pistons but I heard I need to have valve cuts in tehpistons when running the DOHC head, is that correct? if so I might end up making the cuts into the sunbird pistons at a machine shop.
Also what kind of injectors are avaibalbe for these things to get a little more fuel into them easily, I have a FMU and high pressure pump etc... I also had a copper head gasket made and I'm shooting for 20 psi, tahts why I'd like to keep the forged pistons and anyother forged internals if I can get my hands on them.
Any tips on good set of cams for boost or anything would be graetly apreciated as I know nothing about this motor except the head bolts up to mine, lol
thanks in advance

Post by **PrecisionBoost** » Sun Dec 18, 2005 7:56 am

Hi, I have one 2004 2.0L 16V engine... one 2000 2.2L 16V.... one 1990 2.0L 8V N/A... one 1987 C20GET (2.0L 8V turbo ) and I also have a 2.0L 16V in my 2004 Chev Optra and another 2.0L 8V Turbo in my 1990 Pontiac Lemans.

With six of these engines and three different engine management systems.... I have a pretty good idea about what your going to need to look at. ( I also have a 1987 Sunbird GT... which has no engine.... I bought it for the C20GET )

First big problem with the 16V swap..... most of the accessories have been moved around so the current engine mount is no longer used.

In it's place is the power steering pump and A/C compressor.

So.... you will have to relocate the power steering (and A/C) with a custom made bracket in order to make use of the regular front engine mount.

The wiring will be very very different.... the newer 16V engines use a distributorless ignition system.... so you will either need to go with an aftermarket programable ignition system (such as one of the MSD DIS-2 products ) or you will have to use the stock 2.0L 16V engine management system and hack it to run boost.

Either way.... it's going to be a pain to wire up.

The standard Nubira/Leganza engines do not have any forged internals...... I was under the impression that you were going to use the bottom end of the C20GET with a 16V Head.

Hmmm..... that leads us to another issue.... the 16V engines came with a reluctor wheel to trigger the crank sensor.

I can't remember what year the C20GET got the reluctor wheel (even though it was never utilized in the old sunbird system )

My 1987 C20GET didn't have it.... but I remember someone from the LT3 site saying that the newer ones have it..... perhaps the 1990 and 1991 models..... not sure.

So.... if you don't have the reluctor wheel on your C20GET crank.... you will have to forget about using the Nubira engine management system.

You are correct about the issue of machining in valve reliefs.... very neccissary and not exactly cheap.

I bet they will want at $200 to $300 to do the machining.

You might be better off ordering some forged JE or Wiseco pistons or else buy some C20LET pistons.

With 20psi you will definitly be pushing the limit of the stock C20GET connecting rods..... you could probably get by if you debeamed, shotpeened and then polished them.... but they are a press type wrist pin and most of the aftermarket forged pistons are setup for the floating sleeve like the C20LET.

Once in a while you see a complete set of C20LET connecting rods, pins and pistons on EBAY ( UK )

I'm not 100% sure that the valves in the Nubira head are a perfect match to the C20LET pistons but we will find out very soon as Tom from 360 Dynamics will be trying the fitment sometime in the new year.

I noticed you mentioned a copper gasket.... I've heard they aren't exactly the greatest for sealing the coolant/oil passages.

Cometic makes a really decent multi-layer steel gasket.... it can be ordered in any thickness and they are super strong.

As far as injectors.... they are easy to come by if you get a Nubira engine (2.0L) or Leganza engine (2.2L) but it's a little harder if you were to try and use the parts from a newer Optra or Forenza engine (2.0L)

tango · Post by **tango** » Sun Dec 18, 2005 11:54 am

You asked about the swapping of the 8 valve head for a 16valve head. It's not that simple because I do believe the bolt pattern is different. Stick with the 8valve head. The power disadvantage is minimal really.

Mr_Efficiency · Post by **Mr_Efficiency** » Mon Dec 19, 2005 12:36 am

Af far as wiring goes my plan was to run the stock 2.0 8v turbo sunbird wiring and make it work, the only problem I'll run into then is the distributor wont bolt up to the head so (as crazy as it sounds) I'll be fabing up a bracket to put my distributor with a pulley into an acceseory belt to spin it (I've seen it done before and it worked great) I really want to stick with this harness cause it is made for boost.
as far as internals go I want to get C20LET pistons and rods if I can get a hodl of them and after hanging around this site and ebay for a while I've seen getting a hold of a set may not be that hard, so I might eb going that route, if not I'll have my stock sunbird pistons machined, which I can do for free cause I have access to a machine shop

I never knew about teh power steering and AC issues, thanks for that, I wont be running AC but I want to keep power steering
thanks for all that you've been a big help, if I come up with anything else I'll be sure to post it here

Edit: also I forgot, could I use C20LET rods with teh sunbird pistons? and I noticed theres a lot of C20LET valve covers on ebay and I might buy one just causeit looks kooler and I want a motor that says "VAUXHALL" on it, lol, but will that cover bolt onto the daewoo head? I'm pretty sure it will just want to be sure.
And yes teh bolt patern is teh same for teh heads I've seen teh swap done before.

Post by **PrecisionBoost** » Mon Dec 19, 2005 3:02 am

Yes... bolt pattern is the same.... and yes.... I've seen the distributor run off the accessory belt before as well.... but I think it's dangerous... if that belt slips a fraction it will throw your timing out and boom....disaster.

To make the most power you really should go distributorless..... you can get an aftermarket ignition system with a crank trigger to make it work with the C20GET wiring harness.

The C20LET uses floating wrist pins... the C20GET uses press pins.... so they aren't compatible.

The C20GET rods have been known to run as high as 350hp ( Ned from J-Body forum had a completely stock bottom end)

Personally if your going with the stock 8V turbo pistons.... keep them with the 8V turbo rods..... have them debeamed,shotpeened and polished.... and you shouldn't have a problem.

And no.....the C20LET cover will not fit onto the daewoo head..... the C20LET and C20XE head is a totally different design.

Tom@360Dynamics had a couple of covers that will fit.

I want to get a bunch of aluminum ones made up with Opel or OPC engraved into them.... but I have more important things to work on right now so I probably won't get to it until summer.

Post by **PrecisionBoost** » Mon Dec 19, 2005 3:14 am

As far as what Tango said..... the difference between the 8V and 16V is roughly 15% to 20% more power at a given boost level.

If your just looking for power...... then stick with the C20GET and crank the boost up a little higher

If your looking to be different then go with the 16V head..... but the cost to get it setup might be significant.

Some things you may not have considered..... if you swap to the 16V head you will need to use the 16V intake and exhaust as they are completly different than the 8V

You can buy the manifold for the 16V from Tom@360Dynamics

Now... if you use the 16V intake..... then your control systems and sensors are going to be different..... you may have trouble with items such as the throttle postition sensor.... hard to say....you would have to have the two side by side and measure the relationship of voltage vs rotation.

The idle air control will be different.... and it will idle like crap if you take it out.... especially if you get cold weather.

You will also have to get rid of the EGR setup..... the 16V turbo manifold doesn't even have a hole for it anyways.... so again... no EGR= bad idle when cold.

There are probably a dozen different things you haven't thought of.

For example.... if you use the 16V intake.... odds are the throttle cable won't fit so you will have to get a custom cable made.

I suppose you could cut off the flange of the 8V Turbo intake and have someone weld on a flange from a 16V intake..... that would solve the issues related to different sensors and throttle body position.

So.... I wouldn't do this swap unless you are prepared to do a whole pile of modified brackets, modified wiring, modified intake and modified exhaust system.

The manifold for the 16V engine is setup for a T3.... so you will need to make a custom downpipe and modify your exhaust system to accomidate the external wastegate.

Mr_Efficiency · Post by **Mr_Efficiency** » Mon Dec 19, 2005 3:41 am

I had no idea teh stock bottom end could handle that much, I'm never going past that much power thats for sure, lol so I'll stick with the stock bottom end then.
Yeah, I've been thinking about the intake and exhaust thing and I was going to fabricate my own intake and exhaust manifolds, that way I can make them work with all the C20GET sensora and such.
I know it wont be much of a power diffrence, I'm just doing it cause liek you said, its diffrent, how many twin cam turbo sunbirds do you see everyday.....
I know it will take a lot of fabricating but thats what I do all day, I have a full shop with everything avaibalbe to me and I build race cars so I never stop fabricating, everything on our race cars is made from scratch, so I'm pretty good with making up brackets and such so that shouldnt be a problem, and yes I'm sure I'll run into many unexpected problems I never considered but you cant be prepared for everything....
I'm going to have to some how work an egr system into it cause I need it to pass emisions test every other year, and about the distributor thing, I never thought of it like that I'll have to do a chain on it then to eliminate the possibility of any slipage.
And I was just looking at pics of the head from a daewoo and the head from a isuzu rodeo/amigo and they are the exact same and the isuzu has a valve cover thats the same as the C20LET one, have you ever tried to swap them or are you just assuming, I'm not saying your wrong or anything just, I'm so sure they fit...maybe I just dont want to believe they dont fit, lol, and I also saw pics of the C20LET head and yeah its way diffrent than both of them.
thanks again for all the input

Post by **PrecisionBoost** » Tue Dec 20, 2005 12:50 am

Yes... Isuzu used the 2.2L in the Amigo and Trooper starting in 1998..... so they have the same head.

Ok... if your fabricating your own stuff..... then it's easier.... I wasn't sure of your level of knowledge....so I wanted to make sure you knew this wasn't a super easy swap.

Post by **Efratech** » Tue Dec 20, 2005 5:00 am

You should look on my engine build thread...

that way you can get some idea on some custom built parts...

the covers on the XE/LET and the old ecotec (daewoo engines) are different... Tom@360 sells some Opel covers for those heads (i personally like the blue OPC one)

Post by **Efratech** » Tue Dec 20, 2005 5:04 am

Just read that you have all the tools... lucky guy

Mr_Efficiency · Post by **Mr_Efficiency** » Tue Dec 20, 2005 2:20 pm

I wasn't sure of your level of knowledge....so I wanted to make sure you knew this wasn't a super easy swap.

Yeah no problem I know what you mean I do that all the time to ppl on j body sites cause you never know what they can do or how much they know, and yeah I know its not a cake walk to drop this thing in, but I'm up for doing all the fabrication to make it fit.
So you say the isuzu uses the same head as the daewoo? then the valve cover from a isuzu would fit a daewoo then, right? the iszuzu one is pretty much identical to the C20LET/XE ones, I was looking at it more closley today and I saw the isuzu dosent have all the bolts around the edges of teh cover to hold it down, so if anyobne wants the C20LET cover just for the look of it, I'm pretty sure an isuzu one will bolt right on.
and thanks Efrain A. I'll be sure to check out your thread.

Edit: Also someone mentioned something about a motor mount that needs to be fabricated, anyone got any pics of it so I have an idea of what needs to be done?
thanks