J41a2 Anyone?

[IDon'tKnow]

A J series engine with the J37 crank and some 95mm slugs would displace 4083cc's.

Who dares me to do it?

[jacobuchanan140]

Betcha wont!

[hondaboy4life]

Do it!

[IDon'tKnow]

Betcha wont!

We could put some money on that (and I could put it toward the build).

[RMXmitch]

party. party. party.


:)

[RPM SYSTEMS]

my question is , could you get a big enough cam's for that stroke and bore?

[IDon'tKnow]

my question is , could you get a big enough cam's for that stroke and bore?

Some guys seem to think that for every 100ci of displacement increase you need an extra 10* of duration on the cam. If that is relatively correct across the board, the 37ci addition in this case would want ~3.7* of extra duration.

The short answer is "no" I suppose; compared to the J32, or J35, the same cam in a larger engine is going to, relative to engine size, perform more mildly. It will still produce more power across the board.

Somebody needs to source the manufacturer of Honda's cam cores so we can start toying with the cams. It's the lack of cam options that has me thinking of other ways to bump the power band. Extra compression only goes so far.

[acidbath124]

you could look into the cams that bisimoto is doing those may help. i think you have to send him a core set and its about $722 i think. i meant to ask how would you get it to 4.1 liters? the reason i ask is we were doing the math the other day for using an oddyssey crank and rods and i think it came out to 3.47 or something like that granted we may have miscalculated in some way. i am very curious in this because i to had been wanting to figure out a way to make a 4 liter engine outa the j series.

[IDon'tKnow]

You would need a J37 crank (96mm stroke) and a 95mm bore. The blocks come in 89 and 90mm bores from the factory and you can't go much past that, even with a press-in sleeve because the cylinder casing narrows as it approaches the bore center edges.

So, to get this displacement:
1. Wet sleeve the block
2. Get custom pistons
3. Get custom rods (not a requirement, but you'd be crazy not to)
4. Modified OEM head gasket.

I would probably do some copper o-rings on the cylinder head face as well.

[Nersh7]

Doing that in your MR2?

banana's son

[IDon'tKnow]

I'm pretty sure I'm going to try; I can tell you that I know for sure that there will be wet-sleeves available for the J in the coming months.

[JCharged]

Try it, if it works, I'm next. :cool:

[BigJ]

Thinking about this, wouldn't wet sleeves be more prone to hot-spots since the dampening effect of the aluminum is no longer there?

I am just comparing this to my fancy german cooking pots that have aluminum sleeved into the base of the stainless pots for more even heat distribution.

what I'm getting at is, would there be inherent issues with boiling at the top of the sleeve, in the vicinity of combustion area?

[IDon'tKnow]

Thinking about this, wouldn't wet sleeves be more prone to hot-spots since the dampening effect of the aluminum is no longer there?

I am just comparing this to my fancy german cooking pots that have aluminum sleeved into the base of the stainless pots for more even heat distribution.

what I'm getting at is, would there be inherent issues with boiling at the top of the sleeve, in the vicinity of combustion area?

Wet sleeves are what's used in the highest cylinder pressure engines with the highest compression ratios: While I see your points, I don't know how to quantify the extent of the dynamic changes and can only assume that they are not significant enough to worry much since they are well proven in commercial diesel and race engines.

Since the chamber is designed for a smaller bore the quench area will be greater and the air/fuel mass will be concentrated toward the center of the bore @ TDC.

You might also consider that there will be a greater exposed area on the chamber face which should assist in transferring more heat to the cooling system.

[nutnut]

Thats sweet, definitely interested :-)
Whats your view on further increase of the stroke?

[IDon'tKnow]

Thats sweet, definitely interested :-)
Whats your view on further increase of the stroke?

I thinking extra stroke is going to be a tough task in the confines of the J series block. In addition, negative effects on piston speed and rod ration would make it completely out of the question IMO. The J's are already pretty heavily over-square.

[Nyborg Garage]

Who have you talked to since you know that there will be wet sleeves coming out soon? And did they say 95mm was possible?

That super hight revving J25A 3-liter engine is looking more interesting :)

I have mailed Darton my self, but the guy was on vacation ATM.

Feel free to PM me if you want :)

[SonicRacing1]

In for the build

[jkriss]

It just sounds right...

[ekswapdude]

any more progress on this j41 build or not?

[IDon'tKnow]

It never took off. The build isn't really in my budgetary constraints right now.

Golden Eagle was the one I had talked to about The sleeves. They said they were just waiting for someone to order one because they had to tool up for it; also, that Bisi had dropped a J32 block off to them to use when they were ready to get to work on it. I told him I was going to need the largest bore they could possibly do and that I would be ready to move on it in a couple months (this was way back when this thread was started). He said "cool, we'll get started on tooling today, and we'll be in touch."

I would have pulled the money together to for the sleeved block if I had to. But, as most of you might know, I have so much fabrication and custom machining work I'm just waiting to get the funds together to cover, not dealing with this right now is probably a good thing.

I would still like to do something like this in the future, but right now I just have too many projects going to start over on my bottom end build. I'm just one of those people who can't decide where to draw the line sometimes; I think to myself, "well, this will only cost XX dollars more and it's way better".