The only difference that I have been able to find between the 90 LN3 (Vin C) and the 92 SI L27/67 is the PCV passages and intake design, and that the L27 comes with roller pivot rockers. from all appearances the Blocks are identical! hell even the cam'* and T chain and thrust button are identical-even the oil pump drive looks the same.
from the top they look different but in their hearts they are both essentially SI blocks
maybe not by what the manufacturer calls them but the Vin C is essentially a SI the 89 is a little SOL as I havent compared it to the VInC LN3 but I believe that if it has the blance shaft (87 and later) this swap will work as the primary engine differences are in the heads and intake...which would be getting swapped for SII components.

Here are prices straight from the Aurora U pick a part yard here in IL, for those who want to see how much cheaper this is than swapping in a SII longblock, harness trans etc. especially if their shortblock and trans are in good shape. Now if you have a blown shortblock/trans you may be better off getting a SII engine and/ trans etc.

Cylinder heads 76.00 38.00 ea.
Camshaft 26.00
Intake 22.00
valve covers 14.00 7.00 ea.
Fuel rail 22.00
Injectors 66.00 11.00 (ea? not specified)
Ex manifolds 38.00 19.00 ea
X over pipe 10.00
EGR electronic 31.00
MAF sensor 16.00
Throttle body 41.00
SC/turbo 60.00

total $ 422.00
to put a SII L67 top end on a SI block (gaskets and T chain extra)
Gasket set ~ 120.00 T chain set ~ 82.00 (shop around as these are average prices)

total for our project 280.00 + 200$
to put SII L67 heads with L36 intake and our own 12 injectors into the 442
this is a total without the Injectors, SC/Turbo, and MAF sensor

If your swapping in an L67 longblock you can easily spend $600 or more for the engine and still pay ~ 120 for a gasket set to make srue there are no leaks. and this doesnt include the cost of the L67 Harness/computer or trans if it is swapped in also...

The feasability (cost wise) for this project goes up greatly if you have the SI 3800 and the shortblock and trans are in good condition...if they are not then you would be better off getting all the L67 parts (hopefully you can get them in great condition for a good price) to swap in.

Regardless of all this...It is at least possible for a competent gearhead to accomplish this swap.

I hope this puts things into perspective for most of you out there...
Regards, James

in this project the biggest question was whether i could put the early SII cam (in 97 they went to a larger cam bearing journal size) into the SI block to actuate the valves in the proper sequence (the SI has a valve arangment like this...EIIEIE where the SII is IEIEIE) well i can now say without a doubt...nope the lifter bore spacing is dead on on the middle 4 lifters but has one lifter in a radically different spot on each opposite end...
so in order to have this project continue I would need a custom SI camshaft with the SII lobe phasing (but i can wick up the duration and do a couple other turbo friendly changes to the lobe profiles)

heheheh now fer the redneck part....I have identified the 4 lobes that need to be rephased...and since i can weld...cast iron even. I can weld up the surfaces that need to be off base circle and have a cam company grind the lobe profiles...however i have found out that a friend with a lathe has a pattern follower.... so it would be possible to take the camshaft lobe profile from my Turbocharged 400 sbc aftermarket camshaft....and grind this camshaft with it... :green: though it would probably be wayy too big for the 3800...though since i will be keeping the stock (SII) rockers i can machine the heads to handle much higher lift (at the valve)

so yeah i can still doit! woot!
now the SII cam is close enough that i can use it to mock the engine up with (the rollers on the hyraulic lifters not being 100% on the camshat lobes but since i will just be mocking it up to determin intake spacer thickness and custom pushrod length...this is no problem...

ahhh redneck lowbuck hotroddin'

at least its not a flat tappet camshaft....then it would be harder for me to grind it on my own...and hell i dont really need a lathe...i could do it on the Bridgport at my old buddy'* house...but a lathe would be more repeatable...

sooo how many of ya have ground your own custom cam...lol

(BTW sooo many people say that nothing will interchange between the SI/SII...they have NO clue how similar these two engines really are...)

that is all... stay tuned for more to come...

James

Hmmmm.....didin't we warn you about the valve sequence difference at the start of all this? It'* pretty obvious when you look at the front exhaust manifold.

ummm yes that was obvious from the outset, but the part i was most concerned with was the LIFTER bore spacing differences...where the cam lobes are in relation to the cam journals (which are in the exact same spot and both use the same camshaft snout though the retainer plates have different bolt patterns)
this was the biggest question on the whole project as it would determine whether i would have to get a custom SI camshaft with the SI lobe spacing pattern but with the SII lobe Phasing...
which i will be fixing in a redneck engineering manner...mentioned above
everything else so far has been a bolt on deal...

and since many wouldnt mind getting a better aftermarket camshaft i dont see this as too much of a hickup...

Locksmiff (StreetCommodores.com-down under) and I have discussed this but i wished to see the differences myself...

by my rough estimates this would mean the two of the pushrods will be at an angle of 3* in relation to the lifter bore centerline...hardley a concernas BBC have as much as 7* pushrod missalignment from the lifter bore centerline...

if i were to start making a hybrid "KIT" to sell ther wouldnt be very many parts involved...as it looks as though the SI pushrods are the correct length to use with the SII heads though i am still going to be mocking it up to determin if there is enough hydraulic lifter preload especially on the two particular pushrods/lifter/rockers...

pics will be forthcoming as soon as i get my digicam back...

regards, James

Some new info:

http://www.oldsconnection.com/forum/...ce703985#12445

Regards, James

OK fer an update....

i was talking to my buddy down under, (Locksmiff on Streetcommodores.com,) who started a seperate invite only tech site for holden commodores...(weee i'm one of 120 select few who know their sh!7! lol...naw he started it to keep the flammers out from the other holden boards and concentrate on going fast/tech articles...i wish i could let you see some of the stuff there...but i wont...i will copy and past fer you guys when i find something relevant to ya'll)

but to the case at hand...

I have some pics of the SII stuff mocked up on his Holden SI (same as ours but has different intakes and exhaust (they got RWD but not quite the same stuff as the F body 3800 stuff...)

here are the SII heads on the SI block...

The cover over the balance shaft kinda hides the lifter bores but here is a valley view (btw i have never seen that blance shaft cover on an american engine...we think this is because of the high temps of the Au market...keep oil from coking on the underside of the intake)

And the money shot...here is the SII Holden intake bolted to the head...you can see the 1 inch gap that would have to be filled with spacers...or the SII intake widened...

and here are a couple of shots of the holden SII upper and lower intake manifold...similar to the F body setup but not quite...



now if you look at the lower holden intake it might be easy to cut it in half down the middle and widen it (cut zigzag between the runners and straight down the middle on the bottom) and then weld in filler for the coolant "T" and just fabricate a sheetmetal common plenum for the top...
alteernatly we have been talking about just making a custom (sheet aluminum) lower intake as a tunnel ram...which would be great for a NA engine but on our turbocharged setup ahort runners would work just as well...

well i hope that gives ya'll some more stuff to chew on....

I hope to get my own SII heads here soon so that i can start mocking up pushrod angles etc...but the heads bolt on nooo problem

James

I wish I could have an aussie intake to play with.. A while back I saw this:

http://www.supersixmotorsports.com/
EDIT: thats the ford 3800 intake GM intake is just below it at the cataloge (pdf-no linky):
http://www.supersixmotorsports.com/P...005catrev3.pdf

now that would be a bitch to widen....

I'm missing the whole point of this hybrid. Seriously, I could put an LS6 in a motorcycle, but why would you?

In this particular case, you're mixing Series 1 and Series 2 parts for very little gain over just doing a full swap to begin with.

Haven't you said this a few times already?

It'* fun for one reason.