BRAAP

Ok guys… How many of you V-8er’s have dreamed about getting rid of that distributor at the back of the engine all together? I know I can’t be the only the V-8 Z guy that has had this thought cross his mind. Wouldn’t it be nice to hook up your timing light and seethe timing pointer actually be STATIONARY, i.e. no spark scatter? No more fly weights and spring tensions to deal with and gum up and stick as they age? No more corrosion build up on the inside of the distributor cap to clean out on a regular basis? DIS is sounding pretty darn nice eh? Remember when electronic ign came about and available for us regular car guys and how much of a benefit it was to us tuning our cars for max output? I personally see DIS as step or three better than what electronic ign was to points! (boy did that sound like a sales pitch or what? Sorry guys. DIS is just plain COOL!!! I, in no way benefit if you go DIS other than to see others move that much further into the electronic age). We’ve recently been playing around with some of these DIS parts and will hopefully have my first distributor-LESS system up and running in one of my Z’s within the next couple months. My first project is my SOLO-II F-prepared 240 Z powered by one of my mild race flat top L-28’s with Maxima N-47 head. Then my V-8Z project will also get the distributor-LESS ign as well, but not till later in the year, sorry. Even one of our beloved moderators is toying with this exact same system on his SBC V-8 Z… (I’ll let him make himself known if he so chooses to make it public). Any how, I went down and purchased a complete 6 cylinder AND 8 cylinder distributor-LESS ign system from the wrecking yard. Ign modules, coil packs, crank sensors, and crank wheels, all totaled under $100 for both a 6 cylinder AND an 8 cylinder system. Now there is one more piece to make this system work. You can either have a complete standalone EFI system that controls the DIS, such as Mega Squirt, or an ign only system such as Mega-Jolt control this DIS set up. For those of us guys that are allergic to carbs, the Mega squirt EFI controlling the DIS ign is the way to go. For those die hards that love their carbs, (and there is nothing wrong with that, carbs make AWESOME power when tuned properly), the Mega-jolt system would work for you. There is a bit of research to do on your part to get this up and running. Myself, as many others feel, getting rid of the distributor is a step forward in the realm of maximum performance potential. Here is the Mega-Jolt ign only info… http://www.bgsoflex.com/mjl/mjl_edis.html Here is the Mega jolt source to purchase a prebuilt or DIY DIS controller.. http://picasso.org/mjlj/?q=node/10 Here is the link for those of us that also want MPFI along with our DIS!!! Within the link you’ll find info that directly covers the DIS ign… http://www.megasquirt.info/ms2/ The parts are Ford parts. I know, I know…. FORD.. YEUCK!!! I for one am not a Ford fan especially ancillary parts. The only Ford parts I truly appreciate are the small block engines which are EXCELLENT power plants, no matter what anyone else says. Any how, Ford engineers did an AWESOME job designing and building this DIS ign system for 4, 6, and 8 cyl engines. The more I research the Ford DIS and the more I play with it in on my DIS test bench, the more I appreciate the efforts put forth from the Ford engineers. Kudos to Ford on this DIS! For amore in-depth look at our venture into the DIS set up and the details pertaining to our DIS test bench, read this thread. Lots of good pics as well… http://www.msefi.com/viewtopic.php?t=14920 For those curious about the progress of our current DIS project and even more tech info... http://forums.hybridz.org/showthread.php?t=103781 We have gone so afar as to build a test bench to run my EDIS-6 and EDIS-8 systems, (Ford refers to the 6 cyl wasted spark DIS system as EDIS-6 and the 8 cyl system as EDIS-8). The test bench has been invaluable and will help answer many question in the future as well. Any how, Here are a few pics of our test bench with my EDIS-8 for my V-8-Z sparking away. Ron had the idea of completely cutting off the ground electrodes for a more “photogenic spark display”. I agreed and promptly chucked up each spark plug in the lathe and completely removed any remnants of the ground electrode what so ever, effectively making these cheapo AC plugs “surface gap” plugs. They sure do light up nicely, don’t you think? This pic is the test bench and the EDIS-8 system sparking all 8 plugs on the left…

EDIS-8 is operational. I couldn’t do all this testing today without at least verifying that my EDIS-8 system for my V-8 Datsun Z project actually works as well. Ron had the idea of completely cutting off the ground electrodes for a more “photogenic spark display”. I agreed and promptly chucked up each spark plug in the lathe and completely removed any remnants of the ground electrode what so ever, effectively making these cheapo AC plugs “surface gap” plugs. They sure do light up nicely, don’t you think? Being as I love to take pics with my Nikon D-SLR, the EDIS-8 running surface gap plugs made for a great photo op. I’m sure these are pics that only a true gear head could appreciate…. This pic is the test bench and the EDIS-8 system sparking all 8 plugs on the left… I couldn’t make up my mind which of these 2 pics was more impressive, so here are both of them. All 8 plugs all lit up using 30 seconds of extended exposure. There are over 5100 sparks present in each photo alone… A pair of plugs arcing away… One plug showing its cone of fire… 3400 RPM, 30 second exposure…

Being as the cam is not “over” the heads, but actually under the heads.. . . . ***"SUHC"***… ROFLMAO…..

First the DISCLAIMER!!!!! Now keep in mind that all of the test results we post here are under certain conditions and will not be exactly representative of every setup under all situations. Our battery voltage on the test bench is only 12.3 V. In an operating vehicle running a fully operational electrical system, 13.5+ volts, 36-1 wheels with dirt, grime, and debris between the teeth or covering the VR sensor, or other 36-1 wheels and VR sensors, the results will vary. Not too mention the combustion process has a very strong influence on the performance of the high tension side of the coil itself, i.e. yours and others results can, and will vary. The views and opinions expressed here are ours. The information provided here-in is for entertainment only, not for investment purposes. Lack of torque has been shown to cause big wings to sprout on the back of your Honda, and in some cases lack of torque has been shown to cause cancer in laboratory rats. Void where prohibited, batteries not included. Latest update. Went out his morning to perform some testing to answer Eric Fahls question. (Eric has been very instrumental in helping me sort through my laptop MT and MSnS-E software woes, I’m just glad I have the opportunity to return some info back to him that he can use.). This mornings tests consisted of; 1) VR Voltage measurements, 2) At what VR to 36-1 wheel clearances will EDIS run at reliably? 3) Verify the EDIS-6 firing order, and 4) Does my Chrysler 6 cylinder coil pack work with the EDIS-6 module? 1) The VR AC voltage was measured at different RPMs, 140 rpm, 270 rpm, 1900 rpm, 3740 rpm, and 5600 rpm. These runs were tested using an Escort 36-1 wheel and an Escort VR sensor. All RPM’s were set per the mills settings and then verified using the inductive tach of the DBtoZ timing light connected to the running and sparking EDIS-6. Then I disconnected the VR leads from the EDIS system and clipped on my Fluke 87 DMM to the VR leads for Voltage measurements. Results are in the Excel sheet pictured below. 2) Then I reconnected the entire EDIS system and at all 5 RPM settings with a starting clearance of .045” VR to 36-1 wheel clearance, proceeded to add clearance between the VR and 36-1 wheel until EDIS-6 did something different or strange. I also had the inductive tach connected to see if EDIS would start to scatter or have intermittent spark when the VR clearances became too great. The results were interesting and didn’t seem to follow any trend. Suffice to say, EDIS will continue to spark at great distances, and when it hits that brick wall, it just shuts down, no scatter or intermittent spark. Also, we had the strobe going on the 36-1 wheel/damper to see of the timing would “wander” as the gap increased. NOPE! The ignition events remained ROCK solid steady no matter what the VR to 36-1 gap was, all the way out till EDIS shut down all together, and as soon as I brought the VR clearance back to where EDIS would light back up, timing events were right back where they are supposed to be. The VR to 36-1 wheel clearances at which the EDIS shut down and the clearances which EDIS came back on line sparking, is at the top of the Excel spread sheet below. 3) Firing order of the EDIS-6 was confirmed as in the illustration below… 4) Yes, the Chrysler 6 cylinder coil pack runs on the EDIS-6 Module. On the bottom of the spread sheet is mention of Ron’s voltage test comparing an Escort VR sensor to the 4.0 V-6 Explorer VR sensor on a spinning Escort 36-1 wheel at varying RPMs. The Explorer 36-1 wheel this sensor came from measures approx 3.7” or thereabouts. It appears that we just may have to acquire an Explorer 36-1 for more testing.

Pete P., Ron has already placed a bid on “O” scope on eBay, (thank you ZYA Pete), but Ron may also call that O scope guy today as well. Thank you guys for your help in the search for an O scope. It will GREATLY help prove and/or disprove ideas and theories as well as advance our experiments to another level and shorten the learning curve drastically. Thank you guys…

We are SOOoo looking forward to those pics...

Luis, Thank you for the Kudos… No doubt that we’ll keep everyone up-to-date on our findings as we progress, pics included. BTW, have you thought about bugging Ron Tyler any more about those adjustable LCA’s? I’ll keep the bug in his ear on my end about the LCA’s. Maybe if you help keep that bug in his ear as well it might get the job done that much sooner… I’d be willing to give him what’s left of that.. “hic…” 5th of….”hic”…… Bicardi Gold… hic…., LOL

Pete, Thank you. I’m “cut and pasting” my post that I just posted on the MS-EFI list here as we made large strides forward in regards to the EDIS. YES… All we need now is an “O” scope… Hmm Hillsboro… Yes we SHOULD hook up on your next visit. I’ll buy the beer or Soda, your choice. Yeah, I get over to Hillsboro once in awhile…. Being as Dave Lum, (proprietor of http://www.datsuns.com and owner of the VG30DETT 510 that runs 12’s at 114+ which just so happens to be one of my best friends along with Ron Tyler who lives within 100 yards of my house and HE is responsible for making Dave’sVG30DETT powered 510 a reality), and another friend whom I shoot high end Air guns with is an engineer at Intel, you could say that I get over to Hillsboro once in a while. In reality, those guys make over to my place more often that I make it over to there place, LOL. EDIS testing info… Ok, I was able to finish the test bench today, no thanks to Ron buying me a 5th of Bacardi as incentive to HURRY UP!!! . The Bench is made from a large chunk of aluminum channel with all the appropriate holes drilled and tapped into it for mounting modules, spark plugs, and various coil packs. It is designed for a variety of quick and easy bolt up configs in very short order. On the right end of the bench is where the EDIS module goes, as far away as I could mount it away from the plugs and coils. On the left side are 8 spark plugs with the ground electrodes cut WAY back for much better visual “inspection” of the sparking event, thanks to Ron. I slotted the “channel” in such away that an EDIS-4 coil pack, or an EDIS- 6 can be mounted readily. I even went so far as slotting it for BOTH EDIS-8 coil packs as well. Then I made provisions for attaching the Dodge Neon 4 cylinder and Chrysler 6 cylinder coil packs as well. An all around EDIS 4, 6, and 8 testing facility. I think I covered at least 75% of the applications we might be testing in the future. At that, there is still room for the addition of other coils if the need arises. First test on the new official test bench was my EDIS-6 system for my SOLO-II Datsun 240-Z using the Ford coil pack. Immediate sparks right from the get go, WOO-HOO. We had only one glitch that we still don’t know the answer to. When we shut down our prelim spin up that went perfectly, we set up the camera and went to restart it and no sparks. Hmmmm… . Did we somehow “POP” the EDIS-6 module?! After several attempts, nothing. We checked, double checked, and triple checked all the connections, every thing looked good. Tried spinning the 36-1, and again, nothing. After disconnecting the ground for a period of time and reconnecting it, turned on the mill and WA LA… SPARKS!!!!! No other issues arose during the rest of our initial play time with EDIS-6. (bizarre) We stood in awe for awhile watching those 6 plugs sparking away while the mill run at 1480 RPM, the RPM’s confirmed with my ancient Cornwell “dial back to zero” timing light with built in tach which also has a setting for 2 stroke/wasted spark ign. It is old and slow, but it works, and seems to work fine. I marked the 36-1 wheel with a sharpie and verified that the EDIS-6 does spark, off of the 6 tooth back from the missing tooth when set up properly. We expected the spark to be triggered at the “middle” of the 6th tooth, but in reality it was firing at the trailing edge of the 6 tooth (with the timing light set at 10 degrees BTDC. With the timing light set on zero, it was triggering off of the trailing edge of the 5th tooth behind the missing tooth as expected). I tired to get an accurate picture of this, but the angle only partial shows what I’m talking about. You can make out half the metal core of the VR sensor in that particular pic, and yes, that pic was taken with 36-1 “spinning” at speed and the timing light strobe visually stopped the 36-1 as it came around in the picture. I know I’m forgetting something else but I’m sure Ron will fill-in whatever I missed, right Ron? Overall, it was pretty neat to watch those “spark bolts” all lit up. Depending on our schedules over the next few weeks, we hope to do more testing, though no guarantees. I have a customers cylinder head that takes precedence over ALL other projects when it arrives… The pic below is the test bench all ready to go. Left to righ:…, Spark plugs, EDIS coil pack next to that, EDIS-6 module, then the DBtoZ timing light, and the 36-1 wheel in the quill. Behind the whole apparatus is the automotive battery for power. The pic below shows 6 plugs all lit-up from the running EDIS-6 system, WOO-HOOO... (note the "flux capacitor", LOL).... This was our best shot of the plugs doing their job. This was a 15 second exposure and I think the 36-1 was spinning at 3400 RPM or there abouts. Ron would remember the exact RPM. At any rate, hundreds if not thousands of sparks are captured in this one picture. This picture shows the 36-1 wheel spinning, (right hand side of the wheel is a blur from the extended exposure time), while the strobe of the timing light optically stopped the wheel on the left hand side. If you look closely, you can make out the missing tooth just to the left of the quill. The pic below is of the 36-1 spinning under the strobe of the DBtoZ timing light and the camera was able to capture exactly what we saw. Note that the spark was actually occurring at the trailing edge of the 6th tooth. We were under the impression it fired in the middle of that tooth.

Just a few quick pics of our make shift EDIS test bench in operation. Today we will fabricate a more user-friendly dedicated EDIS test bench for not only verifying that our used parts actually do work, but it will also be very beneficial for our future VR and 36-1 wheel testing once we acquire an “O” scope… For now we did learn that VR sensor wire orientation is critical. If they are backwards, no spark, as per our first attempt. Swapped the VR leads and WA LA!! SPARKS!! This initial test is an EDIS-4 system for the Datsun 510 of Ron’ Tyler’s wife, (his test mule,… The CAR is his test mule.. C’mon guys..). This system is using a Dodge Neon coil pack. After we get the dedicated test bench fabbed up, we’ll also test my EDIS-6 running both Ford and Chrysler coil packs and then test my EDIS-8 system destined for my V-8 Z project. Sparks a plenty.. The test bench in its hastly prepared glory, (but it worked…), with the Escort 36-1 wheel spinning away with an Escort VR, Neon coil pack, and four NGK plugs sparking away on the Mill table… The spinning 36-1 wheel and the DRO indicating .0475” clearance between the VR and the 36-1 wheel.. (when we opened the clearance to .090”-.095”, we completely lost the freq signal from the VR).

Pete, Here is that Flywheel with 36-1 cast into it that I told you I’d post here. I guess this set up is pretty common on the Euro Fords. A set up similar to this on the L-series would help clean up the front of the engine bay, especially for show cars, etc. Any how, being as there isn’t really much info out there when it comes to custom 36-1 wheels of varying dimensions and various VR sensors, we are trying to answer all of our questions on our own. it would be nice to know the requirements such as tooth width/thickness, depth of the gaps, etc on the 36-1 wheel, for various VR sensors so that we can duplicate the best we can, the OE signal from the VR to the EDIS module. Ideally would like to either machine notches in the back of the Datsun flywheel similar to the flywheel pictured below and mount the VR in the backing plate, or machine notches around the perimeter of the flywheel and mount the VR in the bell housing. I’m sure that as the 36-1 wheel grows in diameter, a different VR sensor will be needed as the “tip speed” of the teeth will be greater as compared to a smaller wheel at the same RPM, and that higher “tip speed” will generate more voltage from the VR as compared to a smaller 36-1 at the same RPM. Tooth thickness might also play a role in voltage production as well, but don’t really know for sure without proper measuring equipment. Also, not sure just how much voltage the EDIS module can handle on a regular basis, so we would rather be safe and just do our best to duplicate the OE signal, from all aspects, the best we can, from our custom wheel and VR arrangements, hence the need for an “O” scope.

Pete, Those hoses wont be there long, that is for sure. Like you said, those clamps do and will work loose, and as such, will be getting AN fittings sometime this year. In the mean time, I’m going to run the current Oil lines and being as this is a SOLO-II car, it doesn’t really see much run time during races and I have a pretty strict “nuts and bolt” session I like to perform the day before each and every race, i.e. go over the entire car with a handful of tools checking all the important stuff, like fastener tightness, hoses, electrical connections, fluids etc.

Thank you for sharing your electronics expertise and helping out with the electrical end of this project. I did get the Chrysler coil pack mounted in the car today. It is mounted on the passenger strut tower. I utilized the Chrysler mounting bracket, only had to bend and twist the ear just a little and it essentially fits the car perfect for this location. I’m not overly happy with location from a cosmetic standpoint, but functionally it’s fine. I’d prefer it to be a little lower as it seems to over power the passenger side of the engine bay a bit “jutting” out as it does. Maybe next winter I’ll relocated the oil filters so that I can lower the coil pack. For now, this’ll have to do… In the picture below, you can barely make out the EDIS-6 module nestled under the fender in the upper right corner.

Pete, Thank you for the tips. I appreciate your helping me with this. My strengths are engine building, performance cylinder heads and cylinder head machining, engine tuning, and a little bit of chassis knowledge. Electronics is fun, but not my strong point. Your description defined the “shielding layout” of this diagram perfectly. Thank you very much.

Yeah baby, "Dual Head Over Cam" ….. PERFECT, Oh and don't forget the "16 Valve" emblem as well. You’re not lying about what your packing… just being honestly creative with the today’s automotive acronyms…

Thanks for the heads up on the shielding. I don’t really know much about shielding other than it is supposed to help keep EMF or “electronic noise” for altering or interfering with the signal being sent though a wire or pairs of wires I “think” understand what you are saying about the floating end. By “floating” you mean don’t attach the shielding to anything on that end? What is “dual conductor” shielding? When I ordered my MS from RS Autosports, I also ordered 20’ of the “1/4” braided wire shielding”, http://www.rs-autosport.com/ (scroll ¼ way down the page and you’ll see it there). What are your thoughts on using that for my VR, PIP, and SAW shielding? Also thought about wrapping aluminum foil around the VR, PIP, and SAW wires as well as twisting the VR wires. Am I overkilling this or approaching this shielding thing the wrong way?

Pete, Yeah, off the top of my head, that sounds like it should work… Finally brought home the Chrysler coil pack. It looks as though it will work just fine… The Chrysler coil packs has what appears to be the GM HEI high Tension lug, and if that is the case, this will allow the option of pretty much ANY manufacturer of spark plug wires at a very reasonable price. I’ve tried looking for nice wires for the Ford EDIS-6 with pretty much no luck. Specs… Primary resistance of the Ford coil packs was measured at .7-.9 ohm on my Fluke 87, (no idea why the range other than maybe the connector on the coil pack?). The Chrysler coil pack measured .7 ohms on all three coils, so electrically, it should work. Also worthy of note is the back side of the Chrysler coil pack is FLAT, which makes mounting it in various locations that much easier than the Ford. When mounting the Ford Coil packs, try utilizing the OE mounting bracket the coil was mounted on in its donor vehicle, this will help tremendously. The Chrysler coil pack makes mounting it even that much easier. Here are the are the pics… Also, here is where I mounted my EDIS module last night. Just under the passenger fender on the forward side of that little vertical piece of sheet metal. This places it nice and close to the battery and the coil pack.

C’mon guys… Are you building Show cars or great handling sports cars? You guys seem hell bent on trying to fix what AIN’T broke and letting the front suspension remain with all of its issues. You guys did read about the front suspension being the weak end of the Z car right? It was right here in this thread…Sure the rear isn’t perfect, but from a performance standpoint, the rear works pretty darn good and it works FAR better than the front. i.e. the FORNT really needs your attention before the rear. Just trying to find out if you guys are more concerned with building Show cars or wanting to apply true handling performance mods to your Z? Building a show car with a cool unique rear suspension is OK, nothing wrong with that, but it looks bad when when you perform mods like this to a system that isn't the weak spot in the first palce, and then portray it to the rest of the world as being for performance reasons when you let the real issue slide, i.e. in this case, leaving the front end with all its issues....

Pete, I’ve seen other plugs that supposedly fit the EDIS coil packs with similar coil ends as those Jacobs. It looks as though the coil side of the plug fits “inside” of the Ford coil pack. Hmmm… We’ll have to look into that little more … As for Jacobs Ign, in the past I used to rave about Jacobs wires and their products, the quality of the parts from their factory was always good and I do still like their wires, but ever since Jacobs sold out and is no longer truly Jacobs anymore, (they are run by some other company), all their manufacturing went to Mexico and every set of wires of theirs that I recently purchased over the past few months has been CRAP quality in regards to the assembly there in Mexico. 5 sets of universal fit wires that I use for Datsun L-series, and a set of ceramic boot wires for a customers V-8 project. The issues I have is with their lack of training for those putting the wires together. When they silicone the ends on the idiots doing the work in Mexico are letting the silicone drip down into the sockets, down the inside of the boots, I have found sockets installed back wards, mix matched sockets in the package, etc, absolutely NO quality control coming out of the Jacobs factory any more. After I use up these final sets of Jacobs wires I have in stock, I will NOT EVER purchase or endorse any of their products. (sorry for going off on that tangent.) Back to the EDIS install… As you noted, with EDIS-6, you need to place the VR sensor 60 degrees downstream of the missing tooth. Being as this wheel has 36 teeth, that makes each tooth exactly 10 degrees, so with that info, 60 degrees is 6 teeth. Another way to set the 36-1 wheel timing when using the EDIS-6 system is to set the crank at TDC, and then count 6 teeth counter clockwise from the missing tooth, (as viewed from the front), and the very middle of that 6th tooth is where your VR should line up, as per my final picture. That way you don’t have to find 60 deg BTDC on the crank. This link is good source for help with setting up EDIS. http://megasquirt.sourceforge.net/extra/edis-hardware.html Here is some more good EDIS set up info… http://www.megasquirt.info/ms2/EDIS.htm

The A/C mounting brackets will be a much easier install compared to what I did for my race car. I was planning on using the Ford coil pack, but just yesterday while I was at the U-pull-it yard getting another Escort VR sensor, I noticed the Chrysler 6 cylinder coil pack on a Mini van and also a Chrysler car. Hmmm.. 4 wires feeding this coil pack like the Ford coil and the high tension terminals are like the GM HEI posts…. The only issue I’m having with the Ford coil pack right now is the need for those fancy clips on the coils which seems to be pert-neer impossible to get GOOD wires for. I want to run Magnacor wires. I ‘m 95% sure I’m going to go back to the U-pull-it yard today and get that Chrysler coil pack, at $25, even if I don’t use it, not that big of a loss right? I’ll report back after I get it home and get a chance to measure the low tension resistance as compared to the Ford coil pack. I haven’t made up my mind on whether to mount the coil pack to the block or the fender well yet. If the darn oil filter boss wasn’t in the way, that would be the ideal location for plug wire routing, but as you suggested, for reliability reasons, the fender well might be better. I do find it odd that but both Ford and Chrysler has these coil packs mounted directly on their engines… apparently these coil packs can take that kind of vibration abuse… Here is the FINAL painted pic of the VR bracket… After installing the 36-1 wheel I wasn’t totally comfortable with that press fit so I set the damper up on the mill, spot faced, drilled, and tapped 2 holes for 5x.8mm bolts. I drilled exactly at the mating line of the damper and 36-1 wheel. (I expected the 36-1 wheel to be HARD, but it is actually quite soft and very machineable.) This way the 36-1 wheel can’t rotate as it is doweled by the bolts and the bolts will also keep the 36-1 from walking fore and aft as well.

First off. RS Auto sports does a REMARKABLE job of building the MS controllers. I just ordered an MSnS-E V-3.0 with the Relay board, universal harness, sensors, relay board-controller cable, etc, and had them set up my MSnS-E controller to run the EDIS-6 distributor-LESS ign for my F-prepared Solo-II L-28 powered 240 Z. The controller itself arrived yesterday and words can’t describe my feeling on the quality of work they do. First rate through out. You are making a good choice having RS-Auto sports build your MS for you. As for which ignition trigger you need, that’s up to you. Get with “Mobythevan” and he’ll steer you in the right direction for your boosted L-series. He seems to be VERY MS savvy. If you were running N/A I’d recommend the Distributor-LESS EDIS-6 system, but not sure how the EDIS system works on boosted application…. In fact, just this morning I finished roughing in my crank trigger mount assy on the engine and posted pics here.. http://forums.hybridz.org/showthread.php?t=103781 I’ll update tomorrow afternoon with more pics of the final painted assy, looks way nicer than what it posted currently.

I’ve seen a few liners on N/A engines that have come apart for one reason or another, including my second L-28 in my BRAAP car. A couple little pieces even fell into the chamber, had to remove the head to get them out and smooth out all the little divots in the chamber roof for those pieces bouncing around in the running engine. I suspect an overly lean condition over long periods caused the liner to run hotter than it was designed to and not to mention all the heat cycles that the liners go through over the 100,000+ miles that are on these cars currently… Any how, I don’t have any first hand experience running a Turbo on a round exhaust port with the liners, but my guess would be that the exhaust runs SO much hotter on a Turbo engine that the liners just wouldn’t live. The liners are sort of “free floating” hen they are cast into the head as and as such, they don’t have any place to allow all that heat to dissipate to, i.e. they aren’t touching the aluminum of the exhaust port itself which would help dissipate the heat. I could be wrong and as you said, it would be nice due the plentiful P-79 heads to use this head. Of course you could always spend the time removing the liners yourself and that would alleviate the worries, though have you ever tried to remove those liners yourself? Boy oh Boy that is a project. I would be curious as well if anyone else has run a turbo on a Round port with liners?....