Project MX-3L

[ZUNE MX-3 Gs]

I think that turbocharge or supercharge a K motor is really hard, so I thought of why not overbore a Kl motor? I did some calculations and I´d like to share opinions with guys with more knowledge than I about the K motors. I did some calculations, and I figured out that to have 3000cc of displacement (this is what I marked as target),each piston should measure 92,628 mm of diameter, and with the Kl pistons you would have a 11,05:1 comp ratio. I found it too large for a 3L, so I measured how much a 1mm head gasket would take out (assuming that the standard gskt measures 0,5 not sure about it) which will lower that ratio to a 9,835:1 (a bit more logical for a street car). Then I read that the Kl-ze has larger intake valves and harder springs, so I think it would help a lot in performance. Then I was wondering on how the a/f ratio would become, as with more displacement it would ingest more of everything, and I thought on a fuel pressure riser to give it more juice and not to lean it too much. Another handicap is the Ecu, probably with the Ze ecu, it will have better performance, but at Wot, the maximum air assumption would be wrong, so it should be reprogrammed on that way, due to it´s larger aspiration.I'd also would mount the ze camshafts, due to it´s more agressive lift and larger duration. The throttle body that I´d choose would be a 65mm overbored kl tb, or the Ms-8 one(better performance?), but this are assumptions without any calculation. The intake runners, and injectors would also come from a Ze.Headers should be upgraded to a bigger bore to let it breathe at it´s best (I didn´t find out any ideal bre to them). I would choose the kl flyweight and mx-6 tranny just for traction. I would add to this hipotethic list of mods , a full balancing of pistons, rods, crankshaft and a exhaustive porting and polishing to the head, to increase it´s volumetric efficiency to the maximum. I don´t think that an injection booster or larger fuel pump will be required, because it would have a 20% more displacement (another assumption!)<BR>I guessed a cost list and what I will put as the most expensive parts would be the Kl-ze head, intake runners,Tb and Ecu, then it would follow the custom made forged pistons or a used tranny, the custom made headers,the Ecu reprograming, and the cheapest thing the cylinder block worn out, that shouldn´t be too much expensive. The job of boring the cylinders also would be expensive (not have any idea of how much) and the porting and polishing will be everyone´s choice. <BR>You will say that it would be too expensive, but guys, the imagination is free!

[David Coleman]

Uh, there's no way you're going with 92mm pistons. Anything above 86mm is going to be pushing it. Stock is 84.5mm. Now think more about lengthening the stock stroke from 74.2mm to more like 86mm, you're talking ~3L.

[David Coleman]

Uh, there's no way you're going with 92mm pistons. Anything above 86mm is going to be pushing it. Stock is 84.5mm. Now think more about lengthening the stock stroke from 74.2mm to more like 86mm, you're talking ~3L.

[ZUNE MX-3 Gs]

What does "to push it up" mean?

[ZUNE MX-3 Gs]

O.K., I have looked to a picture of a Kl head and there isn´t too much room for boring that size, , sorry!

[ZUNE MX-3 Gs]

If you enlarge the stroke, what would be a better choice: look for custom pistons or do a spacer?<BR>(any of the above doesn´t look very good)<BR>It´s true that a 3L block from the K series exist?<p>[ June 28, 2002: Message edited by: ZUNE MX-3 Gs ]

[Zoso124]

Never heard of a true 3.0L block but I've heard of 2.9L but thats tough to believe. From what your putting together it would be your best bet to buy a ZE and then get your block work done. I don't know what you have in mind, Lower or Higher compression but custom pistons will cost roughly $550 regardly if you overbore to .060, Rods go for about the same if you want them to be forged. I don't know what rods you would use if you decided you wanted to cut down the crank to make it a stroker engine. Boring the cylinders is cheap, but putting in aftermarket pistons & rods is where it really adds up. I would think your talking close to $3 grand to complete the bottom end like stated.

[Stevech_2001]

ya you would have to stroke it....get some forged pistons and rods..port polish.....and then later on maybe get a wet nitrious set up (75-100 shot)...but all motor is very expensive and will give you little results for money paid...just get or refresh your current 2.5 (I'm assuming you have a kl-03) put a supercharger on it and save lot's of money in the process...that's what I would do.....

[SE-Man]

The max the machinist would go on mine is 2.2L on my K8. The parts and work was free, but said it would have cost about $2K if i had to pay for it.

[quinn_seipp]

this is kinda off topic but does anyone know the diameter of a supra piston??? [img]shrug.gif"%20border="0[/img]

[ProtegeSTS]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by SE-Man:<BR><STRONG>The max the machinist would go on mine is 2.2L on my K8. The parts and work was free, but said it would have cost about $2K if i had to pay for it.</STRONG><HR></BLOCKQUOTE><P>He could have gone more...you can get a K8 out to about 2.4L through just boring.<p>[ July 20, 2002: Message edited by: ProtegeSTS ]

[David Coleman]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by quinn_seipp:<BR><STRONG>this is kinda off topic but does anyone know the diameter of a supra piston??? [img]shrug.gif"%20border="0[/img]</STRONG><HR></BLOCKQUOTE><P>86mm.<P>You can go out to 86mm on a K8 block, if you resleeve.

[quinn_seipp]

...nice, lol, thanks alot coleman