Is the 84' engine interchangable with 87' ?

[Olli.D]

Hello from Germany!

I have a 87 turbo intercooled very stock and like to have a second engine.
I like to rebuild it and get some more HP! May be lots more...
Thise engines are very rare in Germany.
Now i get an offer of an 84 turbo hot air engine.
Is that a good base for my project?
Where are the differences?

Thank you for help!
Olli

 

[SHADOWII]

Hi pilgrim, as the picture reveals, the majority of the long -block is different from the 87. You may be able to use the short block, but it has a 14 bolt oil pan. Not the 20 bolt that the 86-87's have. The heads are similar but lack the bridging in the water passage at the end of the head. You would want to swap everything else over, i.e. intake. headers, etc, in order to use it in the 87 gn. Hope this helps.

 

[turbofabricator]

Agree with the first response, though there is no advantage to the basic engine block and heads between '84 and '87. ANY even fire Buick V6 can be built to handle 600+ HP. (Crankshaft being the weak link in a non turbo application, though). Find any 4.1 Buick V6 to start your build, and it will be just fine at 600 HP with a good tuning. (No detonation). If you can't find a 4.1 litre, then any 1979 or newer Buick 231 V6 will work. (Must be a rear wheel drive car, though, as front wheel drive engines are different.)

 

[matt921]

Hi pilgrim, as the picture reveals, the majority of the long -block is different from the 87. You may be able to use the short block, but it has a 14 bolt oil pan. Not the 20 bolt that the 86-87's have. The heads are similar but lack the bridging in the water passage at the end of the head. You would want to swap everything else over, i.e. intake. headers, etc, in order to use it in the 87 gn. Hope this helps.

Some 85 blocks had a 20 bolt pan. I have one in my engine its a 140 block. From reading on here 140 blocks came in 85 turbo Buicks. Only thing is 84-85 blocks were weak in the valve valley. The casting on them is rough. I am in the process of converting my vbelt set up to a serp.

 

[horndog]

The 20 bolt oil pan was in 85, not sure if they had 14 bolts early 85s.
All you need to do is get an oil drain hole drilled and tapped on the block. Heads, rotating assembly, maybe cam are virtually the same. The block is the minor difference, with the lack of the oil drain.

 

[T- Type Tim]

Don't bother drilling the block for an oil return

Weld a 10an bung on the oil pan and run the drain line that way.

 

[Boost231]

Why not tim? Super easy when it's apart.

 

[horndog]

Why not tim? Super easy when it's apart.

Yeah why not? I would figure the flat tappet cam would like the extra oil on it.
Anyone know why Buick engineers chose to drill a hole in the block versus running a line to the oil pan?

 

[T- Type Tim]

I would be concerned about shavings getting in the block

Sounds like you are going to do it while the entire engine is apart so no issue.

Second , I have read that a return straight to the pan is better because you are not draining super heated oil thru the cam bearings.

Either way I'm sure you will be fine
Just a couple things to think about.

 

[87GNSteve]

The deck heights are different between the two years and use different head bolts.