H22a2 vs. H22a5

[Sailor]

I don't know anyone who's done it - it was a general enquiry.
Someone, somewhere ...

[ek9sid]

For what it's worth, I'm running an a2 in my bb8 as that was the only complete motor I had to hand when my a went kaput. (I know it's not an a5 but...well...you know...)

Seems to run alright. Has a flat spot midrange but I think that's more to do with the physical engine than anything else. Swap was straight forward as I reused the inlet mani, exhaust mani, alternator, pas pump, ac pump etc.

HTH

EDIT: And I'll be swapping engines again very soon (when my boost build is complete).

[Drax]

h22a5 into a 4g that had a h22a2 - no issues? all the same apart from swapping over the vtec solenoid as they will need the oil pressure sensor? I know the a5 is open deck and a tin sump instead but that makes sweetfa difference.

[wurlycorner]

If you're using all the ancillaries off the a2 (i.e. incl. injectors) then should be fine (different OBD-yo!)

[Doggo]

Closed deck v's open deck.

Anyone fancy explaining to me what this means please, ideally in small words? I've no idea.

[mercutio]

if you look at the top of the engine minus the head so you can see the cylinders a closed deck block is just a lump of metal with holes in it for the pistons and some smaller ones for the water and oil. An open deck block is the same block but without any metal on the top of the block and four cylinders like drain pipes in the middle

[Doggo]

Thanks, Merc.

Hmmm. So in open deck there's a big space around the pistons until you hit the exterior casing?

What does this mean? Guessing...

Open deck - lighter, harder to increase bore size, easier to cool, less tough, more modern?
Closed deck - opposite?

....or I guess it's more complex than that, at least

[mercutio]

basically thats it i suppose its better cooling for the liners

[Sailor]

The 6 cylinder engine block in my old AC seemed to be modelled on a biscuit tin with bean cans in it.

The cylinder liners were spigoted into the block's base and the bolts for the sump and the sohc head squeezed the whole lot together. You could increase the bore sizes by replacing the liners. Messing with the stroke was a lot harder.

The engine came out in 1919 and was used in one form or another until the mid 1950s, so something must have been right.

[Doggo]

Sounds slightly bizarre. But as you say, if it worked...