4XF1-WT project

[John Syracuse]

Well, some of you have probably seen me speak to this before, but I'm just getting started now on assembling a 4XF1-W (1.8L from the JI body Isuzus, Impulses and Storms) to drop into the Elan. I'm going to say right now that I'm going into this with absolutely no certainty that it's going to fit, just gut feel.

The block of the 4XF1-W is said to be about an inch taller than the stock 4XE1-WT. I've actually have had the chance to compare both side by side in my years building up my Geo Storm. The extra stroke of the 4XF1-W is 21mm, not quite an inch, but the valve cover of the 4XF1 is also shorter than the 4XE1's. My guess is that the extra height is really somewhere in between half to three quarters an inch.

When my Geo Storm had a turbocharged 4XF1-W using the IHI RHB5 for a thunderbird, it hauled serious ass. Not to take away from the 4XE1-WT, but in comparison it candidly feels dinky, especially in the low end where the longer stroke of the 4XF1-W accelerated out of turbo lag effortlessly. Lamest part of the 4XF1-W? Stock pistons. These things are dinky! I never bothered building these 4XF1's for turbo when I was still working on the Storm, I just happened to pick up two of them from a junkyard that was having a special on them, two for $150! At the time my Storm was converted to turbo with a 4XE1-W (the normally aspirated 1.6 DOHC) that I just bolted up a stock turbo from an Impulse RS onto along with a few other fuel management mods. I just slapped in a 4XF1-W instead and I don't ever want to go back. Problem was that the pistons can't take the abuse well, I blew both of those motors, both times piston failures. The first one, on a hard fourth gear pull it shattered a piston skirt. Drove it with the shattered skirt for a while before realizing that was the problem, still was able to beat a VW Corado, ha! Second one, I was experimenting with a new fuel management piggy back, the Greddy E-Manage, didn't pull back the timing cause I was also using the normally aspirated ECU with a 2-bar MAP sensor and DSM 450 cc injectors, second time around the block it hauled then blew, two pistons melted with skirts fractured. My solution is going to be forged pistons which I'll post pictures of when I can get them small enough to post.

Anyways, point is the 4XF1 might not fit. I have a contingency plan if it doesn't, I'm going to at least give it a try before going with any contingency.

The 4XF1-W that's going in there is actually one that my buddy assembled and I bought off him after he decided he didn't have any more time for Storms. His solution was to go into Suzuki Samarai's, mine was to upgrade to a Lotus Elan! The head is ported but needed a valve job, have that taken care of now. It's a very sweet looking motor, has a Fidanza lightweight flywheel, ARP head and main studs, the forged pistons and rods, new pumps etc. The one apprehension I have about it though - he bored this thing WAYYYYY over. In my opinion, it's bored too much. Said he wanted it bored over the maximum possible, so he had the pistons forged and block bored 0.10 over. This is why it's funny being an American, I'm a structural engineer and tried to explain to him that he needs to make sure he's telling them 1 mm, which is the largest overbore mentioned in the shop manual, not 0.10. For some reason I couldn't convince him that 0.10 wasn't the same thing, 0.10 to a machine shop (in the States at least) is one-tenth an inch. So basically, if you accept 1mm as the largest overbore based on the shop manual, then to have bored it 0.10 inches instead turns out to be 2.54 mm, or 2.54 times what can be considered factory recommendations. Granted, that doesn't mean it won't work, there are some factory specs you can exceed and never see a problem, but this is one that I wouldn't have messed with. The resulting displacement of this engine is 1.926 L (?!?!?!), which is pretty awesome to say as worried as I am about this motor. I do have an extra set of forged pistons I originally was going to use for my own 4XF1-W a while back which were only forged an acceptable half a millimeter over, they're still sitting in a box and I was actually not even going to bother with this block of my buddy's, just disassemble it completely and build up a spare with the rods, etc. BUT, since I don't even know for sure if the 4XF1 will fit, this is what's going in there so I can find out. After that, I'll play by ear if I want to put together the other block or not.

In any case, the good stuff, assuming everything fits, my intended setup is going to be the following:

Stuff that came with the block of my buddy's
4XF1-WT bored 0.1 over to 1.9L with balanced rotating assembly
Forged crower rods
Forged Arias pistons set to 9.5:1 compression
Ported head missing valves (I have since found a spare set of valves, had a radiused valve job done and had the head milled)
Isuzu rod bearings and Clevite main bearings
Fidanza lightweight flywheel with Stage 3 Clutch from (I think) Clutch Specialties

Stuff I have either laying around or will pull from the Storm for the Elan
Spare intake plenum to port if all this fits
Unorthodox Racing underdrive pulley (I don't think this really does anything, but hey, I have it, may as well install it!)
DSM 450 cc injectors
Greddy E-Manage
Phenolic spacer, not sure if this does anything noticable, but I have it and may as well put it in.

Stuff I still need to get
IHI RHB5 turbo from a Ford Thunderbird (stock turbo doesn't work well with the extra displacement)
Quaife LSD (gotta control traction somehow!)
And of course at some point a better exhaust system for all this.

I'm thinking this is a setup that'll get at least 250 hp, my goal is 300 hp.

I'll get more pictures as I get further into the building of it. Wish me luck!

Chris (a.k.a. booster)

[lotusgirlmarie]

Hopefully this will stuff under the hood. Will watch with interest.

[dapinky]

Problem was that the pistons can't take the abuse well, I blew both of those motors, both times piston failures.

Not overly surprised at that - the NA engine has cast pistons, the turbo unit had forged ones - also a better oiling/cooling system where oil is sprayed up the bores from underneath to cool the skirts.

These issues should be addressed with using forged pistons, but then there is the crank oiling to consider - the turbo big end (or is it Main, or even both) bearing shells have an additional oilflow.

Will be interesting to see how it all pans out....... good luck.

[John Syracuse]

So someone has to help me out here, how come everytime I try to attach a file I get a message saying "Sorry, the board attachment quota has been reached."? What does that even mean, I've reduced the file sizes for these pics to like 45ish kb, how small do they need to be?

I am aware of the piston differences between the NA engines and the 4XE1-WT, as well as the oiling differences. Supposedly, the fact that I'm using forged pistons means I'm not required to have any type of oil squirting anyways, which was strange to me at first but I've read several people online saying such, Crower not providing oil squirters on the forged rods they sent saying they aren't needed for this setup, and an old buddy of mine who built up a 4XE1-WT several years ago telling me he put in forged pistons and actually blocked off the oil squirters. The pistons are better in the 4XE1-WT, but I don't know if they're "forged" or what, cause you get them side by side to custom forged pistons and they don't look near as robust or awesome. They do still manage to make a cast aluminum piston from the NA engines look pathetic though.

[Brit-Car-Nut]

"Sorry, the board attachment quota has been reached."

This is a technical problem with the forum hosting system. It will be corrected soon, we hope.

[Specky]

So someone has to help me out here, how come everytime I try to attach a file I get a message saying "Sorry, the board attachment quota has been reached."? What does that even mean, I've reduced the file sizes for these pics to like 45ish kb, how small do they need to be?

Another way is to upload them to something like photobucket and then embed them. By doing this you can post much higher quality images, and the size doesn't matter.... After you've done the first one it'll become second nature.


As a bit of background information the LEC has paid for a storage area and as such and the size of photographs was an issue, thus members using other free hosting sites was deemed the way to go for a thread on heavy photographs. Also I don't believe you're limited to the quantity of photographs per post. The LEC used to be 10 pics per post.

Hope that helps

TTFN

[John Syracuse]

Aight, I can do the photobucket thing. I usually find myself shying away from those kinds of sites because most of the time I'm using a computer is at work and they block those sites. Either way, some pictures of the Crower rods and Arias pistons against stockers, all for a 4XF1-W, not the stock Elan 4XE1-WT.






Trying to think of a word to describe it,... Awesome maybe? Haha!

[GeoffSmith]

"Sorry, the board attachment quota has been reached."

This is a technical problem with the forum hosting system. It will be corrected soon, we hope.

Problem now sorted thanks to Chris.

[John Syracuse]

Okay, so those of you who had been paying attention to this (prolly not a lot of you), I didn't give up on this project, it was put on hiatus cause I relocated from Denver, CO to Knoxville, TN for an internal position with my employer. My Lotus spent the last three years in Denver in my friend's garage while I was in Knoxville, but my long-term (3 year) temporary assignment was changed to a permanent status, so I've bought a place with a garage in Knoxville and finally got a chance to move the Lotus, etc., here!

Bad news is that a lot of the parts I needed to finish this off got lost over the years and I'm going to have an adventure I'm sure trying to find them again,... blech! At least the best stuff didn't get lost though.

See the pictures, I reinstalled the piston, reoiled the cylinders, and threw on the ported race head. I'm really worried though cause the head gasket opening for the cylinders is slightly smaller than the actual cylinders (the block is bored wayyy past spec), so I'm probably going to have to remove it again and get a custom copper gasket or something.

Anyways, glad to be back and there's no shortage of things that I need to fix that I'm hoping I can get help with. Right now I'm focused on the stupid fuel tank that won't drop, if anyone has a secret how to get this piece of crap out, let me know!

Chris

[rip]

My gut feeling with a head gasket is that if you try to 'get away' with something, you will end up causing damage & paying more in the long run.
If it's been way over-bored, then I guess you'll be creeping up towards a 1.9 instead of a 1.8?

Life gets in the way of many hobbies & projects. It is nice to return to them after a break though.

[Candles]

And the walls between the cylinders are REALLY thin! That's a hard task for a head gasket.

[John Syracuse]

I'm planning on calling a custom gasket place when I get a chance to get a quote for a copper gasket. With the ARP head studs, I can torque the head down something stupidly ridiculous like 80 ft. lbs, so I should be able to get it clamped down plenty for the application.

And it's bored over 0.1, which in the U.S. is a tenth of an inch. Last I checked, the Isuzu manual for the engine only specs you a total of 1 mm overbore, so this is bored over 2.54 times what the manual says. I'm just hoping that the manual only goes up 1 mm because Isuzu only made pistons at 81 mm diameter.

In any case, with 80 mm bored over an additional 2.54 mm, 90 mm stroke, it's not just pushing 1.9L,..

headbang.gif (13.45 KiB) Viewed 18074 times

it's official... (1926 cc)

Chris

[John Syracuse]

As an update relating to the head gasket, I was able to order a copper one today. Good information for everyone, if you want to order one in the future, Cometic Gasket apparently has already got a template for them and have provided them in the past. http://www.cometic.com/custom-gaskets.aspx It's not on their website, but when I called them up and told them it was an Isuzu engine, the guy I talked to said he has templates for 4XC1 and 4XE1, and the 4XE1 is the same for the 4XF1, so I just ordered that.

Cost a little over $60, got it at 50 thousandths thick (about 1.27 mm) with the bores out to 83 mm so it's slightly oversized for the actual bore.

I'll let you all know how it comes out and post some pics when it arrive

Chris

[HJ2]

Exciting! Keep it up and keep us posted

[tb10]

Indeed it is and thanks for the link to the alternative supplier of the head gaskets

[John Syracuse]

Copper head gasket arrived just yesterday, definitely looks nice!

I'll get some better pics comparing it to the stock head gasket, hope to install it this weekend, have to get the torque specs for the ARP studs and some Gasgacinch first though. In any case, only took a week to turn this guy around. One more step closer.

Chris

[dapinky]

Chris,

I noted that you said earlier that you'd gone for a 0.050" gasket - I'd be interested to know how that compares with the standard fittment, and also what other thicknesses they offer.

I know very little about copper gaskets, but I have a head which has already been skimmed by 10thou, which got it (just) within the warp limits as per workshop manual. Ideally, I'd like to take some more off it to remove the warp altogether, but Lotus state a maximum skim of 16thou....

Obviously, if the removal of the Aluminium can be countered by a thicker head gasket, then machining my head a bit more becomes an option, as opposed to making it a big doorstop!

When I rebuild the engine I have got a set of 1mm oversize pistons (Forged ones from your side of the pond), and this may be a way to go forward for me.

[John Syracuse]

I got the head gasket off today and have some measurements (but I have to note that my caliper is literally a cheap plastic piece of s**t, I don't do enough rebuilding and measurements to justify a good caliper):

Uncompressed stock head gasket out of the box - 42 thous
Removed stock head gasket compressed under stock torque specs - 43 thous (yes, I'm confused about this too, I'd think it would be thinner post installation, maybe manufacturing tolerance?)
Copper head gasket for frame of refence - 45 thous

So using the copper one as a known baseline at 50 thou to adjust for my crappy caliper, you'd get the uncompressed stock gasket hovering around 47 thousanths.

The x-factor is how much these compress, I don't know what the compressed thickness is for the OEM gasket or how the copper will compress in comparison, I got to believe the copper gasket doesn't compress as much, but maybe the OEM doesn't compress much either to notice a difference?

Either way, when I called up Cometic, they told me they could do copper in 43, 50, and 63 thousandths (but their website advertises as thick as 93 thous for copper though), and the guy I talked to actually told me 63 is what he usually sells. I chose to go thinner though cause I want to reduce the gasket area that's exposed to the cylinder, but the guy I talked to seemed to think 43 might be getting too thin depending on how much the head's been milled and if the block is decked.

I'm not a machinist at all, but if the stock gasket hovers around 47 thou plus or minus, you'd make up most if not all of the 16 thous taken from the head with the 63 thou gasket. They also have aluminum spacers though, really more for changing a compression ratio though:

http://www.cometic.com/custom-gaskets.aspx

Are you going to deck the block too? Were you going to do a copper gasket or something different? That's where I might be a bit worried with my setup cause now that I have the head taken off, it doesn't look like the block was decked when it was bored over, which depending on how flat and smooth it is will put me at some risk with sealing the copper gaskets. I just have too little material between cylinders to be comfortable with something other than copper that I'm fine taking that risk.

I dunno if any of this helps, the guy I talked to with Cometic was named Nicky though, he was pretty helpful and I'll bet could give you better info or a more educated recommendations at least.

Chris

[John Syracuse]

Literally after my last post, I checked out the price for calipers off Amazon.

I can totally justify the cost of a better caliper.

Chris

[lotusflasherman]

Literally after my last post, I checked out the price for calipers off Amazon.

I can totally justify the cost of a better caliper.

Chris

I use micrometers for anything that needs accuracy. Choice of imperial or metric, but my really "cheap plastic piece of s**t" is spot on with it's readings and so convenient.
It only increments in units of 10 thou's, at 5 thou so rounding is good, but has the big advantage that I can read it without having to get my reading glasses