85/86 wr400 to 430 ac

I have been wanting a 430 Engine but not found One. Got an offer to buy a 400 Engine from 85 or 86 . Will the air cooled 430 cylinder fit this block ? /A

Not sure about the top end fitting but I think the 430 pipe comes out the left side and around the frame and the 400 comes out the center between a split down tube.

430 jug will swap on fine. be aware air cooled jugs will not fit liquid frames

You

You can also use the 400 LC studs with the 430AC top end but will need to get some 430AC head nuts and bolts.

Marty

Hi Marty, thanks for the fat bars!!


Steve

I was going to say you would also need the air cooled studs contrary to post 4. I had to switch the 4 cylinder studs going from an water cooled to air cooled in the 500. Air cooled ones were longer I think. Check the part numbers if really curious. The frames, tanks, plastic, exhaust to work our for an air cooled engine will be for a frame with the 12mm swingarm pivot bolt instead of the 14mm one on the mono shock. The reed cage for the air cooled 430 is the earlier design.

Thanks for answers , Engine is going into and ac wr 82 frame . / Å

You will also need the 12mm ID sleeve that press into the centercases for the swingarm pivot. Unless you have an AC frame with an elongated right swingarm pivot hole, then it would be prudent to open the hole in the frame to 14mm and weld hardened washers on the(outside) pivot locations to reinforce the thin metal. Make sure the 14mm pivot is long enough to accommodate the addition of the washers .

I do not really follow this. Are you discussing the locating pin/cylinder at the case junction at the rear? A 12mm rod will fit through a 14mm bore. I repaired the case, made new inserts of the 12mm inner bore and never split the engine to change the locating pin. Often on used engines for those mono shock bikes the insert is missing as well as the locating pin.

A 14 mm swingarm pivot bolt will not go through the hardened parts the bearings ride on (for the dual shock bikes). The pieces that sort of resemble piston wrist pins.

Dumb question will the single shock swing arm sleeves from the swing arm bearing go into the twin shock bearings? Then the 14mm bolt will go through the engine and swing arm bushings. Then we drill the frame holes to 14mm?

I wonder if there is steel bushings or making steel bushings from Thompson shaft to replace the 12mm twin shock bushings in the swing arm. Just thinking out loud sorry.

To use a newer LC case in a AC older bike. I have two newer LC cases with the larger amount of clutch plates.
I guess it's easier to change out the 14mm bushings in the engine to 12 mm bushings.

I guess it's easier to change out the 14mm bushings in the engine to 12 mm bushings.

asked and answered bill

i dont think you need the cases to run the bigger clutch. just the clutch cover or run the newer four stroke cover which has the room.

I am pretty sure the length of the aluminum portion that the swingrm bearings go into is less than the length of the steel portion of at least the few years prior. See the picture attached it is not like a single piston wristpin like the steel swingarms have. I do not know what is available for the mono shock swingarm bearings now but as I recall those and the 85-86 linkage bearings were not too close to the originals.

It seems to me the engine cases put into the mono shocks have a bit more material at the point being discussed here.

They went to more plates and then later 87-88 went to more springs and larger diameter plates. He probably had in mind the earlier size and more plates than say 1982. Some models, I know the 430, changed the primary reduction so the torque on the clutch got more in the water cooled era.

You can tell on clutches as the later model clutch unit is a 6 spring and is bigger. Happen to have a later model 6 spring hub and need
the bigger cover from later years that has additional cover on case

You can add a sleeve on the 12mm swing arm bolt to use the later case. Its thin but rick horvat made a sleeve to use for me.

Plan on using later cases but will use the 14mm swing bolt in future. Rather than the sleeve. Thanks - frank did not know about the case pin sleeve needing to be bigger. I plan on boring out the bushing/ pin deal the the needle bearings ride on - so I can use the bearings i use all the time

I like the idea of the bigger swing arm axle. Thought about adding thickness to swing bolt mounts with HVA s pre made frame inserts made to fix elongated frame hole.

But maybe we want a bit of flex or give as not to crack cases

Hope I make since.

Oh rather than me make the bushings. I have Rick making me some new bushings for this delayed 500 cr I have been building.
I just feel better as the is custom fit based on size of egged out case holes are.

So he boring the hole out, and sizing the bushings to fit.

I have two newer cases with the larger clutch I'd like to use one in my 430cr build.

My suggestion of using a 14mm single shock pivot is to take advantage of an egged right side pivot hole in the frame. As I have not done such as of yet , it was a suggestion and not a complete re-engineering analysis that I am certainly capable of . As far as the spacer at the case centerline, a solution that I have designed will eliminate it, solve the problem and then choice of pivot size is a decision as to bore the new interlocking flange sleeves for 12 or 14mm pivot size depending on intended future usage.

fi

find one of these cases to run...90s italian four stroke. this allows the 6 spring clutch. this was on my old 84 wr250. old picture but you get the idea.

I picked up a scraped 12mm bushing case just for the bushings. I'm just wondering if there's a way to use a 14mm bolt.
I have the wider clutch covers for the newer cases.