4/6 liquifire

[lwb140]

anyone put 4/6 jugs and ignition and carbs on a liquifire bottom end,? will this work ? are parts that interchangable i have found a cache of old 4/6 engine parts none complete wade

[JoeRainville]

Wade,

The 1980 Invader 4/6 motor is of the T-7 family, same as that of the 80-84 Liquifire. You can use jugs alone, or use the entire top end or the entire motor in an 80 LF. It's been done a by a few of the guys. If you use the Deere carbs, you will probably need to slightly increase the main and power jets to over the 6 to 10 extra hp.

-Rainville

[lwb140]

thanks joe , is there much advantage to the 2 plug head? the invader heads from what i can read were smaller chamber, those would look stock with the better jugs might make a cool combo, he does have the tuned exhaust but only one carb ,would there be any performance advantage to going with a flat slide carb setup ??

[Mean Green]

The 4/6 engine was unique only in it's port design and multi plug ignition. However, if you run a "deere" bottom end, your initial timing should be set at 22 degrees, well beyond the deere initial settings. The dual plug ignition is not necessary, however I recommend getting a set of Invader heads to keep the compression up there. This results in more bottom end and better efficiency. Since you're probably not going to get too crazy on this fitting a set of dual pipes, or even the better flowing Invader pipe, your stock jetting should be pretty close. It will be a little lean, so installing slightly bigger jets will be in order. Likewise for the 4/6 carbs, installing these will require you to decrease jetting as the deere pipe has different flow characteristics than the twin pipes which these are jetted for. All in all, the stock LF developed around 64 HP. The 4/6 was at 76, winning the 24 hour endurance title beating the Polaris Centurion. Leaving out the dual plug ignition and the twin pipes, I'd guesstimate you should be right around the 70hp range give or take. Things to take notice of are as follows...1) The pistons and rings are exclusive to the 1980 4/6 engine and extremely rare. They do not interchange, and installing invader/liquifire pistons/rings into these jugs will eat your cylinders. 2) Timing is important. Kawasaki had much hotter (more advanced) timing than deere. Deere carried out longevity testing on these engines, and their engineers sent very specific specifications to kawasaki for the engines they were to supply deere with. Performance was cut in favor of longevity and real world conditions. Timing and compression were dropped as most people didn't have access to high octane gasoline. The initial timing on the invader was 22 btdc. 3) All 440 liquid cooled kawasaki engines utilised mikuni vm36 "powerjet" carburetors (except for the 81-82 LTD which utilised Kehin. Owners of these "block cylinder" engines ((including the mighty Interceptor 550)) are finding that much more performance can be had by installing the earlier Mikuni VM36 Powerjet carbs). These carbs WILL NOT run correctly with aftermarket air cleaners. They need resistance from the airbox to pull fuel through the "powerjet", or 3rd fuel circuit. If you do away with the airbox, you must do away with the stock carbs and install non powerjet units and re-jet. 4) The PTO side of the engine requires different jetting than the flywheel side. On stock carbs, there is a red dot of paint slightly below the threads on top to indicate which side it goes on. On stock LF, the 3rd circuit jets are 105 "flywheel" and 110 "PTO". 5) ALWAYS replace crank seals if you are dealing with an almost 30 year old engine. ESPECIALLY when dealing with a 4/6 as cylinders are nearly extinct. Seize one of these, and you're gonna be kicking your own butt as they are PRICEY and hard to find.

One last note. I have always wondered how these cylinders would run on the 82-84 bottom end with the newer high speed retard ignition. I know it significantly improved the deere performance. Just wondering if initial timing was advanced, 4/6 cylinders in place and a set of invader heads, how this combo would run....

Tracy

[lwb140]

wow thanks for the info ive got two liquifres in my shop now 80&81 .both with scored cylinder walls and pistons ,trying to figure out what to do with them as to how to fix ,put used ebay parts in them, or buy replated cylinders and new piston kits or somewhere in the middle ,and also do i use these 4/6 parts, would be cool to build a hot rod,.im justa a little reluctant of building something that will require constant tinkering and wrenching to keep running .what is special about the 4/6 piston coatings ring package etc . i dont have any ,are they available new as replacements thanks wade

[JoeRainville]

Hi Tracy,

Thanks for sharing your 4/6 knowledge! I have a few sets of those jugs, just never used them. I do have a question for you. I know the 81-82 LTD "square block" Kawi 440's are near impossable to find pistons for, but I didn't know the 1980 4/6 used a special piston from the regular T-7 Liquids. What makes that piston different, as the jug just has an extra, yet small transfer port in the front of the jug, making it a 6 port vs. a regular 4 port.

As for the 4 plug ignition, I thought the purpose was to allow for a double shot of spark later in stroke (closer to TDC) than with a single plug? I know Cat went back to it on the newer 800/1000 CC twins as a way to help with HC emmisions (reducing unburnt fuel in the exhaust). I wouldn't expect any performance difference between a properly timmed single vs. dual plug head runing gasoline. The 4/6 pipes are another story, as I agree they should be worth a few HP "if" they fit under a stock LF hood.

Come to think if it, after reading Wades note, I do have an NOS set of Kawi pistons with what looks to be an anti-friction coating on them. Are they 4/6 pistons? What makes me wonder is that the typical LF/Invader motors always scuff the piston at the intake port as the gas washes oil off the chrome. Did the 4/6 make that worse?

Thanks,
-Joe Rainville

[tieszo6]

I too would like some clarification. I think we went through a lot of this last fall and there was some talk of whether or not Invader pistons would work. I thought the concern was ring gaps catching a port? Some said the gaps were located such that it wasn't an issue, others said it wouldn't work. Another thing, I called AAEN last fall about putting LF pipes on a 4/6. At the time Olav said it work, but maybe he was just going off that the motors are similar and didn't want to talk to me anymore? I imagine "working" and being a benefit to performance may be two different things here. Let's get some feedback from all you experts out there.

Mark

[Mean Green]

Couple differences in pistons. Primarily the ring locating pin is moved to a different location. Also, the rings were a little thicker than the standard Invader. (Invader part number 13008-3001, 4/6 13008-3008) As mentioned by Rainville, the 4/6 pistons were coated as they are prone to cold seizure. The later block cylinders were not, only the 4/6. To my knowledge the timing is the same as the Invader, but (I'm guessing) the twin plugs were used for more complete combustion and a slight boost in power. Dunno about pipes. The 4/6 ones don't come close to fitting under a LF hood. I ran mine with stock deere pipe and the mod to the y pipe as seen over at kawasakitrax. Reliability was the same as stock LF, it's just got larger porting and once you have it dialed in it's as reliable as it ever was. I did however always run 92-93 octane though with the higher compression and timing advanced. Temp ran a little warmer than stock, but much. It basically made for a sled that would outrun another LF. It's not going to magically turn your sled into a fire breather, but you will notice a pretty good difference especially on the 1980 LF with the higher gear ratio. It actually feels like it's geared perfect with the additional power.

Tracy

[pjr]

Thanks for sharing the info Tracy. I learned something today!

[Trucker]

The 4/6 and 81,82 LTD used the same rings as the JD rings part AM54849 or kawasaki number 13008-3008 you can get an oem replacement yet from Dk http://www.denniskirk.com/jsp/product_c ... mmyId=7435
Not all of the 4/6 pistons had the coating on them.I have had some with and some without and the coating is gone off of them after only a few minutes of run time.
The difference from regular invader pistons and the 4/6 is rings and ring pin location. If you put invader pistons in one of the ring grooves will ride the intake bridge.

[Mean Green]

LOL, looks like I learned something too!!!

[Dator76]

Several years ago I rebuilt my 82 liquifire with just the invader heads and found a noticable difference from doing that. however I then sold it as I was tired of dealing with a motor that slowly goes down hill in performance as the oil wont stay on the intake side of the cylinder wall and it scores. I rebuilt the thing twice, about every 3 years. Would mixing the fuel and deleting the fuel injection take care of this problem. Im not likely to buy another sled with chrome cylinders again as I've got to determine some way of keeping these things from overrunning my shop.lol

[lwb140]

dator 76 , great comments ,ive got 4 of these things an 80 and an 81 that are nice sleds worthy of repair the other two are 80s [all liquifires ]that are pretty rough all have scored cylinder walls, at first i thought my compression guage was broken been fretting for a week as i have them strung all over my shop .try to deside what to do how much to spend, sleeves vs plating new vs used etc i wander if oiling isnt week link or common denominator of all of these sleds .dont want to throw good money after bad i wander if mixing oil even if 1/2 rate with oil injection wouldnt make these motors live better, any comments from the kawi guys on this ??

[Dator76]

im not a fan of over mixing oil as it then fouls plugs and creates a thick layer of carbon on the combustion chamber, which in turn causes it to retain heat, preignition (pinging) etc. one fix would be to nikasil the cylinder which would require oversize pistons and would get rid of chrome bore. but would that take care of the cylinder washing problem caused by unmixed fuel coming in from the carb? incidentially a nikasiled cylinder is very hard. I had a 5hp briggs go 5 seasons that was nikasiled when a regular aluminum bore went 1 season and a cast iron cylinder went 2 seasons.

[lwb140]

have been discussing doing that , but gets pricy , glad to hear you reccomend that as ive been cosidering sending off a pair of jugs to have done thanks wade