Flatlander Racing Stroker Crank...

[5-90]

Here it is - http://www.flatlanderracing.com/strokeramc-258.html

Only problem so far is that they're insisting it's only going to work with the 258. By now, I'm sure you all (as well as I) know that's rubbish - but I'm still working on them.

Right now, I've got a request in for "how'd you make it work with the 258, and how do you make the thing?" so I can get the information and tell them how we can make it work with the 258.

However, I think they'll need some encouragement. I know the kit for teh 258 is about $1600 (yikes!) but it's a bigger performance mod than the cylinder head that came out recently, and I think the two would work well with each other if someone really had some money to spend. However, I'd like to be able to convince them that there might be value in extending the application of this crankshaft to include the 242 (which shouldn't be a large problem, once the parts specs are worked out,) and that it would be worthwhile for them to look into this (especially if they've got someone willing to do all the work but the fine-tuning.)

The fellow I've been talking to there is "Phil" (only moniker given) and he may be reached at [email protected] or 603-378-0090. Here's their shop addy:

Flatlander Racing
24 Elm Street
Plaistow, NH 03865

If we can get these people to see that there's another interested segment out there, perhaps we can get them involved. Since Jake's Racing Engines folded, this is going to be the next best bet for a 'long-stroke' 242 crankshaft - all the better since Jake's topped out at 4.06" anyhow (this thing's good for 4.145 - and I'd like to find out how they did it, to see if it can be pushed any farther. I'd like to know if "cast stroker crank" means an offset ground OEMR casting, or if it means they're casting their own cores, and this could be pushed farther...)

Anyhow, let them know you might be interested, and I think it will help me help them with the engineering. I'd like to see some 'long-stroke' stroker cranks out there, and this might work well for what I'm trying to do with Project: REDSHIFT.

5-90

 

[ren]

If I am not mistaken, wouldn't this allow you to actually build PAST a 5 liter straight six? If so, then that would be AWESOME as far as power ( mainly torque). I may be new at dealing with EFI systems, but I think that I am going to try calling this folks also, and see if some of the other people around here would be willing to call and voice their affirmation for this crankshaft.

 

[5-90]

Let's see...

3.875" x 4.145" = ~293ci/~4.8L (+.000")
3.905" x 4.145" = ~298ci/~4.9L (+.030")
3.935" x 4.145" = ~302ci/~5.0L (+.060")
4.000" x 4.145" = ~313ci/~5.1L (+.125")

So yeah, I'd say it's possible. These are "quick and dirty" numbers, but they look promising. I'll probably wash the crank through some iterative testing with DD2K later this week-end, if time permits...

5-90

 

[ren]

It would be most excellent to be able to laugh at the poor, old 5.0 rustang drivers, and know that, just because you can, you can blow their doors off, probably to about 60-65 MPH with a SIX CYLINDER motor. That, and the torque would be off the scale. I think, if you do not mind, that I am going to borrow your guesstimates on displacement, and work up some power possiblities with different cams, heads, etc... Ren

 

[Beej]

Can anyone speculate as to why they would suggest an overbore of 0.060 to be maximum? I noticed Jon included 0.125 in his numbers above...

 

[ren]

For most engine blocks, an overbore of 0.060" is considered to be the maximum normal, due to the possibility of the cylinder walls becoming too thin, and thus, cracking. If you want to go over the 0.060", then sonic checking the cyl. walls becomes almost a requirement to ensure enough material to support the cyl. pressures of combustion. You can also "sleeve" a block if the walls are not thick enough, but price varies by shop and machinist, sometimes by quite alot of money.

 

[5-90]

Most production blocks aren't designed and built for long-term longevity under great stress.

However, the idea of the 4.000" bore isn't mine - and it HAS been done! I know Mike Parrish has done it at AP (too bad they aren't around anymore - I wish someone would slip a couple details...) and I've heard of it done with a few other 242 blocks as well - the early (pre-OBD-II) blocks seem to tolerate it quite well.

It is necessary to do a sonic check of the block - all cylinders - to make sure that there hasn't been any core shift, or that the shift has resulted in a slightly thicker wall on the thrust face - but a block that passes sonic will do nicely.

It's also an oddity that, apparently, AMC specified the old ChryCo Hemi high-nickel-content casting alloy rather than the regular grey iron that everyone else used.

From my own observations (1987XJ 4.0/AW4/231/D30/D35/3.55) with an early block, these things are tougher than the hinges of Hell. I lost the oil pump in my 87 at just over 200k miles. The oil pump took the crankshaft, #6 connecting rod, and all twelve lifters with it. The pushrods were still perfectly straight, the rocker arms and other five connecting rods passed a dye inspection for cracks.

I replaced the crank, #6 rod, and lifters. Found a hole behind the exhaust collector from where the #6 rod tried to depart the block - it was about the size of my fist. The loose bit of metal was set in place and JB-welded inside and out.

Also, upon inspection, the engine had exactly .001" of top cylinder ridge (meaning, .0005" actual ridge height) on each cylinder. Took me about three minutes with a stone hone on each cylinder to clean it up.

You know, if I'd bothered to do a re-ring then, I'd probably still be driving it. As it was, I did put an extra 40K miles on it before it wasn't pulling vacuum anymore (final ring failure.) I wouldn't think anything of cleaning up that block and using it for a stocker rebuild.

So, while 4.000" may seem like a lot, it's definitely doable, and well within the realm of practicality...

5-90

 

[ren]

5-90, A big THANK YOU fo rthe block info. It looks like I might just go ahead and see if the block out of my wifes' '88 XJ CAN be punched. It has a bad under-cut on the water pump side of the # one cyl. and the weather has caused some rust in the bores since I yanked the head back in the spring, but right now, it is still mostly surface rust and the pistons for the most part are not letting water from the rain into the block too quick- a week or better after a good rain, there is still water standing in 4-5 of the cyls. Man, the machinist in town is gonna end up giving me a preferred customer discount at the rate I am going to see him LOL. Ren

 

[5-90]

That's why I'm taking three of four majors right now...

Automotive Engine Performance
Automotive Engine Machining
Tool & Die Maker.

The fourth is Mechanical Engineering Technology - I'll finish that one in Flagstaff.

Cut out the middleman for myself, and I'm planning on opening up a mod & machine shop when I get out of the PRK...

5-90

 

[rsalemi]

My 90 block is bored .060 - giving 284" on the stroker - with 28K miles of daily driving. if I was to do another I'd go to the 4" bore in a minute!!. Also you can offset grind a stock 258 crank .013 and use .020 bearings to gain a few mre inches (cost $200). You should be able to go another .010 easily - ending up with 3.918" stroke for the same $200. This will also reduce the deck height - my .013 stroke ended up at .018 deck height. This ends up with 295.4 cubic inches without spending any big $$ for a stroker crank.

 

[krakhedd]

Yeah, but stroking it moves the torque curve down - simply increasing bore you'll end up with more torque, but @ higher revs. Increasing bore moves the curve up. This also keeps the piston speed down though, so leads to a little more longevity.

What about OBDII blocks? Different casting than pre-OBDII? I don't know yet where I'd get a block from, but always good to know this stuff for future reference, in case I run into a deal I can't ignore.

 

[5-90]

The basic casting and cores are the same all the way up - but I think the cylinder walls were a little thinner for the OBD-II cores, and a different iron alloy was used (less nickel,) so it wasn't as tough.

As I recall, the boss for the 87-90 knock sensor is always present - it just went unmachined from 1991-on.

5-90

 

[krakhedd]

So, would it/should it be rather simple to integrate a knock sensor into the OBD-II, or does the computer not understand it, or ???

I would obviously be using an aftermarket controller as well, so maybe I should just make sure I purchase one with a knock sensor included, if I were building a 91-on block?

 

[spyder47]

if you get the choice do a 96 or newer block we did research on the blocks and with 96 and newer it has a dowel in the head to help hold the head in place maybe not much but it can't hurt to help keep that head gasket alive. Also the 96 and up is about 15 lbs heavier due to thicker webbing inside and also comes with a stud girdle that runs down all the mains. Very nifty device indeed it actually mounts to all those studs and helps tie the bottom end together better. This thing is way beyond a simple windage tray in strength. I have a complete writeup on my build with pics of everything from this piece to the self done porting w/ flow data , and complete engine assembly and swap and before and after dyno runs. As for those curious for real dyno numbers:

Overall Improvement

Horsepower………….58.8 or almost a 51.3% improvement
Torque………………. 90.6 or almost a 61.2% Improvement

The improvement numbers are over a bone stock 4.0L w/ 206,000 miles on it that still pulled like new with excellent vacuum

 

[Root Moose]

Additionally, according to the magazine articles I have read when researching these beasties, D-C did an FEA/FEM analysis of the 242 block and strengthened and reduced NVH at the same time with the 97+ (96+?) blocks.

It was in a rag, so accuracy should be taken with a grain of salt but the post above tends to make me think there is some truth to it.

Now, engineering is an art of minimalism based upon cost. How little material can we use/remove and still have the object of interest survive its design life cycle?

Because there is less (more?) material are the new blocks less tolerant of abuse/modification? Is the webbing at the expense of a thinner block in general?

Just thinking out loud.

 

[5-90]

If you were to use OEMR OBD-I or OBD-II electronics, the system wouldn't understand it. However, you can still run a knock sensor to a standalone indicator to let you know if your engine is pinging.

If you were to rollback to RENIX, or to use a system that understands what a knock sensor is there for (like, perhaps, OBI-I/II GM/DIS?) all you'd have to do is drill and tap a hole down there to accept the knock sensor, and hook it up. Make sure to use a shielded lead (twinax works well, or wrap the two wires with, say, copper foil and connect it to ground at the bulkhead) to prevent "falsing" at the knock sensor. If the knock sensor leads pick up any false signals, your timing will get retarded and the system won't re-advance it - so shielding that lead is important. If I was doing this from scratch - I'd use a double-shielded "twinax" lead (which you can find through amateur radio suppliers) to assure clean signals.

Either way, if you want to actually use the knock sensor to drive something other than an indicator, you'll have to change a bunch of electronics. I'm planning on experimenting with that one of these days anyhow.

5-90

 

[krakhedd]

Rollback to Renix probably wouldn't pass emissions, since I have an 01. Shit, I don't even know if I could have a different block in there ( = different VIN), cuz of all the stupid laws they have.

Anyway, a unit such as an FTC should be able to incorporate a knock sensor, I'm pretty sure - this is a feature I'll be sure to find in any "piggy-back" unit I may get. I really like my coil-on-plug ignition, another reason I'd like to stick with my stock ECU.

 

[5-90]

That's kinda why I'm thinking of a GM/DIS conversion - waste spark DIS and get the knock sensor back.

I hear you on the "stupid laws" - my RENIX XJ's run cleaner than most vehicles ten years newer, but they still treat me like I'm running "gross polluters" - and I can't wait until I get out of here.

I don't have any trouble with wanting to reduce emissions - but drop the visual, and let us get to work. It shouldn't matter how the numbers are met - just so we meet the numbers. There have been a few times I've been measured at damn near zero emissions, only to fail some BS on the visual. Stupid.

5-90

 

[spyder47]

yeah i hear ya on the stupid laws we have a 74 CJ-5 that failed inspection due to no warm air riser... Soooo we went to the local junk yard and grabbed an aircleaner that fit w/ a warm air rise built into it and ploped it on top of the 4 barrel holley and installed it with the warm air riser touching the clifford intake manifold (not actually connected just resting against it) also never hooked up the vaccuum line. And vua la we passed (rolls eyes).

 

[Dingo509]

Now, engineering is an art of minimalism based upon cost. How little material can we use/remove and still have the object of interest survive its design life cycle?

Because there is less (more?) material are the new blocks less tolerant of abuse/modification? Is the webbing at the expense of a thinner block in general?

Just thinking out loud.

While i see your point, like it was said earlier the newer NVH blocks are heavier. and i actually have one of each in my garage right now and the don't look different from the top at all but if you turn them over you can tell which one i which, the difference is not dramatic but there is a difference.

Dingo