I had this question asked of me yesterday and was not too sure of the answer. What is the difference between a long block and a short block? Is it 4 port versus 6 port ?

 

In general engine terms,
long block means=with heads

Since rotary engines have NO heads.

When i tell someone short block/ I mean a stripped down ROTARY engine,that is still together,No intakes/carbs/FI set up etc etc

When I say long block,That would basically be a complete engine

 

12a=short block 13b=long block, at least thats how the people i ve talked to use it

 

I've always called a motor that has carb/header/alt/pumps a long block, and a short block to be just the block itself.

 

This is what I thought to...

 

Its an engine term thats existed longer than rotaries have existed.....its not in refference to the length differences between the 12A and 13B.

If you purchase a long block engine,it will have a block and head.Typically,there will also be a timing cover and sometimes an intake manifold,but it depends on the engine type.
If you purchase the same engine as a short block,it will be just the block and whats contain within it...like crank,pistons,rods and sometimes camshaft.No heads,no manifolds.....

The rotary doesnt really have an equivelant.The basic bare block contains all the wearing components,so its a complete engine.The manifolds are not wearing items,so theres no reason to need new ones when replacing an engine.
If your buying a rotary engine as a whole its common,for easier differentiaton, to call the bare block a "shortblock" and a complete engine with everything bolted on it,a "longblock"......buts thats not technically accurate.

 

I didnt know long block exhisted. I always though it was big block

 

Big block and small block just reffers to different types of V-8 engines,be it Ford,Chevy,Dodge,ect.....
The big block is bigger(physically,not always in refference to displacement) and the small block is smaller,more compact.

Shortblock and longblock are terms used to describe all engines.Everything from a Geo 4 cylinder to a 454 Chevy V-8 can be a shortblock or a longblock.....it all depends on what you have.....a block only,or a block with head(s).....

 

Thank you all for the replies. Now it makes sense too me. I bought a motor for my boat with just the block and heads and that was a short block ( 350 ). Duh!!!!!!!

 

You could call it the sandwich, with or without the fixings I supose.

 

In that case I'll have a tripple-decker with the lot thanks.

 

Hey this helps me a lot too, i was gonna ask this question at some point.

 

i call the 12A a small block and 13B big blocks

 

lol, the big block rotary

 

So what do we call a 4-Rotor 20A Engine?
Super Duper LongBlock????
Couldn't Help That One.
sgieldon
steve

 

For rotaries specifically, I've always considered "short block" to be just the bare engine and "long block" to be an engine ready to drop in (water pump, alt, intake, carb, etc...)

And it's worked alright like that. Most people seem to share that sentiment, since the direct comparison from piston engines can't be made.

Jon