KJabusa

[JKpgt96]

But Mike...I thought this was only between you and I?!

Looks good, as always, keep me updated, there just might have to be a stab taken at this in the future..after I get my initial 78 year build done. lol

[pgtfreak]

3mm is .118 inches which is far beyond the safe .040 max overbore. And they do not make a 78mm Hayabusa piston unless one of the smaller sized engines have that size. But I am not looking to go any smaller. Larger would be nice but not possible.

The KF is just a "de-bored" KL block. I see no reason why it couldn't be bored to 81mm safely.

I don't even think the KJ has the same bolt pattern for the transmission as the KL.

[KLZE Porsche]

The KF is just a "de-bored" KL block. I see no reason why it couldn't be bored to 81mm safely.

I don't even think the KJ has the same bolt pattern for the transmission as the KL.

From my findings so far - I don't tend to believe any de-bored ideas about the smaller bore blocks. Both the KJ and the K8 have smaller O.D. sleeves rather than thicker walled ones. And the aluminum castings were adjusted as well. I believe they did this to keep the aluminum-to-cast iron ratio the same for efficient heat transfer balance. It is my belief that when people have had problems with cooling when overboring is because the ratio of alumium-to-cast iron was modified enough that it no longer transfered the heat at the most efficient rate. -Of course this is just theory.

But from what I have measured so far on KJ and K8 blocks in comparison to the KL block tells me that they are actually different sleeves. The only way to know for sure if the KF has the same size sleeve as a KL would be for you or someone else to measure the block liner width at the top as someone has done for me with the K8 in another thread.

But even if it does have the same liner -I don't believe the KF is extremely common here in the U.S. I can go to the JY here locally and very likely find a KJ but not very likely to find a KF. So that is the reason for messing with the KJ vs the KF. And it really isn't an extremely huge deal to make cover plates for the end compartments in the valley. And as for the oil jet - I was planning to remove it and just put a threaded plug in there These are extremely easy modifications. And as I cut plates for the covers - I will make the CAD drawings available if others want to try this.

This is very simple stuff even for people who do not do lots of fab work. The only semi-tough fabrications would be something to get back needed bolt holes for the front end of the motor. With the re-drilling of cam pulleys for locator pins I can give an exact location as soon as I have everything lined up and so that would not be hard either. All of this is not really a huge deal for someone with minimal fab experience after I provide more thorough instructions. And I do plan to post up all the steps and CAD drawings as I complete them so that it is a since to do for the DIY fab person.

Also -as for the trans mount pattern -who said they are not the same? I took my spider off the KL that was on the stand and bolted it right up to the KJ without making any adjusments. So that tells me that the bolt pattern is the same.

For those that want to ask "Why?" -the purpose of this is to produce an engine that will easily turn 10k or more RPM without grenading. I know there are many people here who are in persuit of this goal. I get many people writing to me all the time -asking for help to reach these kinds of goals. So I am presenting the information to do it! This comes from my research and instead of answering each person individually - I am posting it publically here so that whoever has the same lust for high RPM can maybe use some of the information without having to do all of the research that I have had to do. You cannot even begin to imagine all of the crazy research I have been doing "that often makes my head spin as well" and all just to discover stuff that people tend to overlook when reaching for new levels.

Another reason for doing this is because so far invested into this project:

KJ block = $60 initial cost for short block but with $200 rebate for rods that were sold -and money back in my pocket I have a free KJ to play with and $140 to put into it!
12 Hayabusa 81mm pistons, pins, rings = $150
Aluminum for block off plates = $20
Gaskets = $60
Overhauled Melling pump = $free

Still needed:
.020 overbore = $60
good KL crank = $40
Clevite 77 tri-metal bearings =$100

I don't see a problem with this because a standard rebuild costs this much or more!

[hppwdn]

As far as I know a G-Series KL tranny will bolt up to a KJ. The MX3 guys had a spare KJ and bolted it up to see if they could put one in an MX3. There's pictures somewhere, but it's an ancient thread and I would be hard pressed to find the picture evidence.

[KLZE Porsche]

As far as I know a G-Series KL tranny will bolt up to a KJ. The MX3 guys had a spare KJ and bolted it up to see if they could put one in an MX3. There's pictures somewhere, but it's an ancient thread and I would be hard pressed to find the picture evidence.

They are the same bolt pattern. There are just a lot of people who do not know much about the KJ because it has been so alien for so long to people that -most are afraid to even touch it. I used to be afraid of it from when I first took a look under the hood at all of that crap. But after you get all of that crap off the engine -it is extremely similar with very few hurdles to jump to make it work for a standard N/A or traditional F/I.

As a matter of fact - if someone wanted to do F/I on one - instead of putting a threaded plug into the port that used to feed the "S" SC - you could put an angled -AN fitting to feed a turbo! And you could put another fitting into one of the fabricated end cover plates to return the oil to the crank case. So -see -it isn't all that scary.

[hppwdn]

Edit, found the post with the info on the tranny. Pics are still live too
http://www.mx-3.com/phpBB3/viewtopic...ler+cycle+swap

[KLZE Porsche]

Edit, found the post with the info on the tranny. Pics are still live too
http://www.mx-3.com/phpBB3/viewtopic...ler+cycle+swap

Yup! I read that article once before. I just wasn't so apt to give up as he was. But I think he was just wanting to see if the Milli "S" in full dress would be a viable swap. I don't think he was looking at just the block as a possible high RPM alternative to the KL with the Hayabusa pistons.

If someone wants to build a high RPM motor then you have to address many of the limitations that keep it from running the RPMs. One is the MPS which is regulated by your piston and upper rod weight. All of the weight that moves perpendicular to the crank shaft seriously effects your MPS.

Here are limitations to higher RPM capability:

MPS limitations (piston and upper rod weight)

Oil supply

Valve train weight and spring rates (springs, retainers, locks and lash adjusters)

Cams

Ignition

Fuel

To hit the higher RPMs - you have to address each of the above. Other factors can limit RPM but the ones above are the most physical.

[hppwdn]

We bolted KL heads to a KJ block once too. Popped right on.

btw, what are your reasons for looking for 10k rpm? All motor power, top speed?

[KLZE Porsche]

We bolted KL heads to a KJ block once too. Popped right on.

btw, what are your reasons for looking for 10k rpm? All motor power, top speed?

Yes - I have already tried the heads too. And actually -I am looking for 12k or more (Bonneville)! So I have a lot more research & development to go.

The only thing I have not tried yet is to check to see if there will be valve-to-cylinder interference with the smaller bore and KL heads with a higher lift cam.

The higher the RPM limit means the wider the power band will be stretched out. And the wider you stretch out the band means the longer you can stay in the power before shifting gears. I need to stay in gear and in power as long as possible due to the taller gears.

Here is a good reference article:
www.wikipedia.org/wiki/Formula_One_engines

Thanks!

MP

[MX6Mejia]

fyi. they do make 85 & 86mm pistons for the busa...(lots o' $$$)
i had to look... lol
keep it up man. cant wait to see this done, hope it all works.
good luck man

[KLZE Porsche]

fyi. they do make 85 & 86mm pistons for the busa...(lots o' $$$)
i had to look... lol
keep it up man. cant wait to see this done, hope it all works.
good luck man

I have contacted JE because the 85mm and 86mm options are great but the only advantage that they would have over Ross, Wiseco, Diamond, JE or other aftermarket KL pistons would be the shorter compression deck height. But my goal is to build a very lightweight piston/rod engine for very high RPM. The difference in weight between Ross and OEM busa (with pins) is a staggering 162 grams/5.71 oz (damn -that is nearly a half pound difference).

So I asked JE how difficult it would be to make changes to the Busa 86mm piston to make it lighter and change the pin size to one I can use with my ti rods. They said they do make a lightweight piston but the price was way more than I was willing to pay. So the KJabusa is still looking good!

[MX6Mejia]

wait you have Ti rods????
oh you're the man!!!
where did you source those rods from anyway???
i was looking around and only thing i seem to find(that are close to our specs) are some Porsche RSR sprint engines. but they are way to much for me to start another rebuild. just finished my engine wish i would have thought outside the box like you maybe i could've done something as wild and as different as what your cooking up. good luck man. cant wait to see the results.

[j-dogg]

Good work, **** the doubters and haters they just mad because you're making shit work or something. KJ isn't as alien as many think it is, and for those who say "no it doesn't fit into Probe" YES IT DOES it's already been done, I think the guy's username is robin. There are pictures of it too.

people want to go the cheap and easy route and boost a stock DE or ZE swap, but there is a metric shit-ton of power available from the KJ-ZEM, I definitely believe that motor had potential as a factory option and no doubt some guy at Ford had once considered using it. It would be like putting the N/A DOHC motor in a Terminator and dropping the Eaton'd version in the Crown Vic only.

[V3rtigo]

The problem with putting the KJ into a probe from the factory is that the Gseries transmission was the strongest FWD transmission Mazda had at the time and it was not not designed to handle much more than 190hp. Ford would have been replacing trannys left and right under warranty.

[lmt bj]

Pauter can make TItanium Rods 6600$ !! for 6 rods compare to 1290$ for 4340 rods....