MX-3.com

Inodoro Pereyra wrote:

mikeinaus wrote:the whole thing looks photo shopped to me. at least the first picture.

Wow...! Good eye!

http://americancure.deviantart.com/art/ ... n-43799491

I lol'd so hard. you guys make me laugh

Glad you're enjoying yourself.
Care to share what do you find so funny?

Inodoro Pereyra wrote:Glad you're enjoying yourself.
Care to share what do you find so funny?

Its pretty funny that no one else mentioned it as a photoshop so early on. The light is all off, not to mention the sizing on the supra headlamps. Simply look at the ambient light in the picture and you can compare the shadows around the car. It wouldnt be that dark with those kind of highlights. Im surprised someone as cynical as you didnt notice that to start with.

Not to mention how many people we have online that are in the design/engineering feild on this forum. The shame!

^^^ Exactly ^^^

when you read back through at what everyone is saying its just funny, then to find out its a complete figment of someones imagination. It was easy to find out if it was fake or not.

I personally love how it looks though. He did a good job on it, only a couple of minor details that could have made it better.

Reading "boared" motor set my teeth on edge.



Does Hotchkiss really make parts for these cars?

Mi|<E wrote:The article itself is poorly worded and full of spelling errors... As far as the car the interior
is no longer an mx-3. The 1.5 L bored and stroked to a 2.2 L sounds fishy too. Max overbore
is ~2.5mm, stroking it with a max overbore id say 1.8-1.9 L is more realistic. The 1.8 L BP
with a stroker kit and overbore is hard pressed to hit 2.1 L displacement.

Toda made a 2.0 stroker kit for the b6, they no longer make them. Last i saw one for sale was probably 5-6 years ago.

I dont think it was an actual 2.0 i think it was a 1.9L stroker with some change, and it was N/A use only with 11:1 comp ratio.

I'd love to see that stroker kit. To get a B6 to 2 L you'd have to get the stroke from 83.6mm to 104.6mm. That'd make for a very torquey engine, with a lousy redline.
No wonder they stopped making it.

So a little research, the TODA 1.6L stroker kit was 1854cc and about 2200. USD.

Inodoro Pereyra:

why was it a lousy redline? 6500 is pretty much the standard? all I did is swap to a BP10 ECU and it revved happily to 7200 . if you wanted it higher than that all you had to do is swap in some better valve springs..

"No wonder they stopped making it." they had it in production for more than a decade, pretty much the life expectancy of almost any production engine.

When you stroke an engine that much, you need to shorten the connecting rods to keep the compression ratio in check, not to mention to keep the piston from hitting the head. The rod/stroke ratio is what determines the safe redline of an engine, not the ECU you use. Not to mention the fact that, with a bigger stroke, your piston speed increases for a given rpm, which decreases reliability, unless you get the redline down accordingly.

Why would a cat that was supposedly "really pissed off" be purring?

Inodoro Pereyra wrote:When you stroke an engine that much, you need to shorten the connecting rods to keep the compression ratio in check, not to mention to keep the piston from hitting the head. The rod/stroke ratio is what determines the safe redline of an engine, not the ECU you use. Not to mention the fact that, with a bigger stroke, your piston speed increases for a given rpm, which decreases reliability, unless you get the redline down accordingly.

All may have some truth, But i am pretty sure that these Toda engines revved out to 8200 rpm.

It has more to do with your cams and valve train and the Balance of the bottom end on the determination of your redline. If your pistons are not hitting your head at 5K then they are not going to magically extend at 7K to hit the head, unless under intense heat and stress. Its the proper balance of the bottom end. I am sure the Stroker kit made it an interference system, which is not a big deal especially if you were running the Toda kevlar timing belt.

The problem with stroker kits, based on my reading, is the increase in piston speed and acceleration. The duration of a revolution, in miliseconds is a constant at a given rpm. When you make the stroke significantly longer, you are increasing the distance that the piston travels in that time frame from 0 ft/sec at TDC to full speed and back to 0 ft/sec at BDC. When you increase the piston speed significantly you increase the acceleration the piston and rod experience when starting and stopping at TDC and BDC as well and that's where the extra strain is placed on the rod which can cause a lot of stretch and a lot of breaking.

A good stroker kit comes with rods that can handle the strain. A poor one comes with crappy rods that stretch and break.

That's all true, and that's why these kits were for NA use only, so they didn't have the extra stresses of FI system. I was wanting to put out there that despite what some say these were great engines. It comes back to your set up and what you are looking to do with it.

Going back i misunderstood what Inodoro had said. My bad. Sorry about that.

Josh wrote: Going back i misunderstood what Inodoro had said. My bad. Sorry about that.

Seems like we're both misreading each other. No apologies needed.

Let's see if I can make myself clear:

There are 2 main problems here:

1. Rod to stroke ratio.

We know the stock B6 rod has a center to center length of 131 mm.
Being that the stroked crankshaft has a 13.3 mm longer stroke than stock, we know the stroker rod will have to be 6.65 mm shorter (center to center) than stock, or 124.35 mm. That has NOTHING to do with the engine rpm range, nor with its valve interference characteristics. It has to do with the piston not hitting the squish areas on the head at TDC.

Now, it is widely accepted that the rod/stroke ratio should be kept ABOVE 1.55:1, to have an acceptable redline (that doesn't mean a possible redline before the engine blows up, it means a SAFE redline, that can be sustained for a period of time, without the need to rebuild the engine completely afterwards). An engine with a 1.52 s/r ratio will go up to 6000 rpm, while an engine with a 1.48 s/r ratio will have a hard time going over 5500 rpm.

In the stock B6, with a 131 mm rod, and a 83.6 mm stroke, your s/r ratio is 1.566985646:1. Not great, but still above the limit.

In the stroker, with a 124.35 mm rod, and a 96.9 mm stroke, your s/r ratio goes down to 1.28328173:1 which is HORRIBLE.
That translates to a higher side load on the pistons (because they're pushing on the rods at a higher angle), and a higher side load on the main bearings (because THE RODS are pushing on the crankshaft at a higher angle).

Now, the B engine bottom end is not particularly strong to begin with. 2 bolt main caps, a support tray that's a lot more effective at controlling oil windage than at supporting the mains, and the fact that the caps are independent (unlike the K series caps), don't make the B6 such a prime candidate to endure that kind of stress.


2. Piston speed.

In the case of the stock B6, with a stroke=83.6 mm, at 6500 rpm, you have a piston speed of 3565.6 feet per minute (18.113 m/s), give or take. A little higher than it'd be desired, but not terrible.

In the case of the stroked B6, with a stroke=96.9 mm, at 6500 rpm, now your piston speed is 4132.8 feet per minute (20.995 m/s). That puts you in motorcycle engine territory.
To keep the piston speed at about the same numbers as stock, you'd have to limit the rpm to about 5600 rpm.

Keep in mind that an increased piston speed not only creates more wear in the piston and cylinder walls, but also produces a higher inertia (and remember that piston inertia can not be balanced out, as it is a reciprocating movement, not a circular one), which produces even more stress on the mains.

All in all, I'd be VERY SURPRISED if a stroked B6 lasted more than a few thousand miles, if regularly revved over 5000 rpm.