1998 Cherokee 4.0 Ltd - Project

[spookie the aardvark]

4 hours ago, PDB said:

Hahah! 

 

Wild fire is natural, and beneficial, and I am natural, so perhaps I should let my nature take its beneficial course? 

"twisted fire starter"

[V]

Thanks for posting this. They have a useful range of products.

 

I checked out the silicon coating, it's the DEI coating that should be good for 800 DegC. Interesting that they suggest coating the pipe before and after wrapping. I also noticed their wrap range covers 500 DegC to 1000 DegC applications. I was stunned that my exhaust downstream of the cat got to at least 660 DegC. It may not be a bad idea to measure EGT under the wrap either with a thermocouple probe tucked between the wrap and the tube or with a probe through a welded bung in the tube. I guess a combination of limited cooling airflow and wide open throttle on the hills pushed my the EGTs higher.

[V]

54 minutes ago, PDB said:

I'm wondering if there is some kind of chemical action such as acids that could cause the exhaust to degrade?

 

I think it is just oxidation during extreme heat. I read Henry Simm's master's degree thesis.

[Fourpot]

Spent a bit of time over the weekend fabricating the aluminium sheet that will create my 'cold air' intake space. Started with cardboard, then thin mdf (which doesn't fold - hence tape to go on the folds), then the aluminium...  I have yet to finalise whatever goes between the filter in here and the throttle body. When I have I can cut out the hole for some tube or other and the breather hose/filter

A lot of hours tidying up various loose ends like the transmission cooler hoses, wiring for the new fans (I have three fans, not as many as Rhianna, but fine for me..) and anything I'd left 'to do later'. I'm actually a hairs breadth from start-up,, which is terrifying me!

Edited November 30, 2020 by Fourpot

[frosty]

looks good, what is your main reason for not going for a conventional snorkel type of intake, i always have a snorkel on my jeeps, i don't intend to drive through deep water, but i have one as a insurance policy, i have been cought out a few times, where a small " ford" has turned out to be a lot deeper, also if you are driving in hot dusty climates,  a high level air intake is a huge advantage. 

[V]

Are you going to paint the shield on the engine side? There are heat reflective white paints available but I think lacquered polished aluminium may be as effective at reflecting infrared.

[spookie the aardvark]

12 hours ago, Fourpot said:

Spent a bit of time over the weekend fabricating the aluminium sheet that will create my 'cold air' intake space. Started with cardboard, then thin mdf (which doesn't fold - hence tape to go on the folds), then the aluminium...  I have yet to finalise whatever goes between the filter in here and the throttle body. When I have I can cut out the hole for some tube or other and the breather hose/filter

A lot of hours tidying up various loose ends like the transmission cooler hoses, wiring for the new fans (I have three fans, not as many as Rhianna, but fine for me..) and anything I'd left 'to do later'. I'm actually a hairs breadth from start-up,, which is terrifying me!

As always looking awesome mate With the huge amount of work of work you have put in on your engine first time starts can always be worrying but i am sure everything will work out ok for an "automotive god" such as yourself

[V]

Fourpot, you should video the first start so you have the sound as well. I have no video and hardly any pictures of my projects before my Jeeps. They only exist in my memory now. You have inspired me to take more photos if only for my own benefit to help me remember what I have done. I hope I get to see your Jeep in person someday.

[Fourpot]

17 hours ago, V said:

Are you going to paint the shield on the engine side? There are heat reflective white paints available but I think lacquered polished aluminium may be as effective at reflecting infrared.

The plan is a layer of the stuff I have, sort of quilted thin aluminium sheet, that I bought to use as exhaust shielding under the car. Or I may just shine it up. I don't expect the reflective properties to be that crucial, it serves to make a separate space for the air. I could have used wood probably...

[Fourpot]

18 hours ago, frosty said:

looks good, what is your main reason for not going for a conventional snorkel type of intake, i always have a snorkel on my jeeps, i don't intend to drive through deep water, but i have one as a insurance policy, i have been cought out a few times, where a small " ford" has turned out to be a lot deeper, also if you are driving in hot dusty climates,  a high level air intake is a huge advantage. 

I've thought about a snorkel, but have no intention of getting that wet. The extra bits on the outside add a lot of drag and complex routing. In reality I do most of my miles (if not time) on motorways, which is why I've taken the roof bars off too..

[frosty]

lol, if you are thinking of aero dynamics, then an good as an XJ is a great truck, it is shaped like a brick, also, it is not really meant for motorways, it is an off road vehicle, and a very good one, even is standard form, i admire that you want it a daily drive, but what is your real goal for this awesome machine ?

[V]

I have built quite a few modified vehicles since I was 17. Most of them were rolling road dyno tuned with a K&N filter of some sort. My '93 XJ still has one fitted, but it will be going back to a paper filter when it's engine gets rebuilt or changed. K&N filters are fine for engines when the owner wants the best power with air filtration. They also have the added advantage of not collapsing when wet. Five years after installing a K&N on my Jeep and 23 years after my first K&N purchase, I saw with my own eyes that K&N filters don't filter out fine desert dust very well.

 

I was driving my old XJ in a desert area of northern Spain. There was a lot of dust during the day and in the evening I thought I would swap over to my clean K&N spare and clean and re-oil the dusty one. When I took off the air filter, to my horror, there was dust inside it and inside my throttle body. I wasn't happy with what I found but I completed the cleaning task ready for the next desert drive. The following evening, dust was in my throttle body again. Too late to worry now.

 

When I returned home I removed the K&N that I had recently fitted to the TJ and replaced it with a new paper filter. All of the Jeeps I have owned and modified since then have kept the original paper air filter elements. After many thousands of miles travelling in US deserts with snorkels and paper filters on my 2001 XJ, I can confirm paper air filters are very good at stopping desert dust from going into an engine.

 

I have never put a snorkel on my '93 XJ but I will do at some point. The K&N filter it still has gets wet every now and then, but it doesn't get sucked into the throttle body like a wet paper filter does. In hindsight, I should have fitted a snorkel long ago. If I had not experienced the dust problem myself, I would probably still think very highly of K&N air filters based on my previous dyno successes. Years later, my '93 XJ (still with the K&N air filter) has noticeable performance degradation when compared to my much heavier 2001 XJ that has always used paper filters.

 

Long term ownership, or high mileage use of any vehicle will reveal some unforeseen consequences of modifications. I don't think I owned any of the cars that I dyno tuned long enough to gain any negative experience of K&N air filters. I have decided that paper air filters are best for how I use my Jeeps. Maximum performance and economy is no longer as important to me as longevity and reliability. We modify our vehicles to meet our own needs. A K&N filter is fine if it satisfies the purpose you bought it for.

[V]

Sorry to hijack your thread again Fourpot. I just wanted to check if K&N still produce power gains on modern engines. I found this dyno test video that confirms that they do. Power gains can also mean better fuel economy. In the 140,000 miles that my K&N's have been on my 4.0L '93 XJ I reckon they have contributed quite a bit to the good fuel economy I have had up until the last year or so as my range on a full tank of LPG used to be 250 miles and I now get around 215.

 

Another video using oil analysis to check air filtration via engine wear and oil analysis also gives the K&N a good result for normal environmental conditions. I don't know how much these tests are in the UK but I think they are useful.

 

I couldn't find any YouTube videos with the same level of dust that I had from just one day of desert driving, but this one had 5,000 miles of use somewhere. Obviously, we don't get dusty conditions often in the UK. Salisbury Plain in summer probably being the worst I have driven for dust.

 

This video tested a mix of paper filters with a K&N and gave some interesting results regarding choice of paper filter. In the last 15 years I have mostly bought WIX, but I have also used Mopar, AC Delco and STP. There is definitely a variance in paper filter performance.

[V]

7 minutes ago, PDB said:

There is a bit of a myth about oil on the MAF sensor from oiled filters. Again a simple preventative measure is squirting liqui moly MAF sensor cleaner on it.

I hadn't heard of that until today. And it sounded a bit dubious to me as most OEMs vent the crankcase into the intake on the clean side of the air filter.

 

I regularly used carb cleaner on Bosch MAF on three family Corsas, every time I changed their air-filters. All but one got really good fuel economy. The problem one had a bad oil sludge problem from previous owner neglect and it was retired to the scrap yard with a blown head gasket.

[V]

Good point, use the right tools for the job. I must have got lucky with the product I was using.

[Fourpot]

. Interesting stuff. There's almost as much on the various media about K+Ns as there is about Covid-19 and as much of it cobblers I think.  In motorcycle world, there are lots of naysayers, most of whom seem to be heavy handed on the oil. The oil should not need adding to until about 100,000 miles, they don;t need cleaning oiling at the same frequency as changing a paper filter, which is the mistake many seem to make. If K+Ns are oiled right (light and NOT often), there's no MAF issue. A MAF is more likely to get fouled up by the black cack that comes back from the engine breather tubes. So many performance and race engines use K+Ns that they must be good. 

I've used them on every car and bike I've owned since about 1981, from minis to MGBs, LandRover, C43 V8 AMG Mercedes, Ford diesels, Citroen diesels, Ford V6 petrol, both Jeeps (2.5 petrol and 4.0 petrol), all my bikes (With fuel injection) from Daytona 995, Tiger 1050, Explorer 1200, Bonneville 1200, a Honda quad....  never problems, only better mpg and performance..   

As for cleaning MAFs, I cleaned the one on my AMG Merc as the engine seemed to be lacking power (in the end I found a knock sensor was disconnected which was the problem). I cleaned the MAF very gently with a wet wipe.

Edited December 4, 2020 by Fourpot

[V]

Not a photo of my K&N air filter, but mine have been this dirty before.

 

 

Fortunately, when mine have been this dirty on the outside they have remained clean on the inside. I don't think I can apply a mileage threshold for cleaning. I try to keep the spare ready to install, which means I clean the filter that comes off straight away. I use the K&N cleaning product and their aerosol oil. I don't think I have ever had a problem with over oiling it's so easy to do I can't imagine how anyone could mess that stage up, but I guess it is possible.

[Fourpot]

Almost nearly on the cusp of being at the point of preparing for first start-up.

Recent work includes all the big current cables (charging, starting and engine earths) replaced and upgraded to ‘fat’ and a 150amp fuse twixt alternator and everything else. Fans wired in with 12v source for the relay switching taken from the coil +.  Transmission oil in.

Battery in... scary moment 1: connect it up. Nothing went bang or caught fire. Ignition on, fuel pump pumps, warnings lights all come on, pause and go off again. I'm sure they shouldn't all go off until the engine's running though, I was expecting the oil pressure and charging lights to stay on, and I can't remember if the ABS light should stay on until the car's moving (my bike needs 5mph for that). I'm leaving it on charge with the battery connected, to see if somehow that'll sort the ECU's head out.

Otherwise, so far so good.

Next weekend will be coolant and oil in, and (maybe) scary moment 2: start attempt.

[V]

My ABS on both Jeeps has been removed, but I am fairly certain that for an MoT pass the ABS light has to come on at ignition key turn and extinguish within 7 seconds. The tester has to see the bulb come on to prove it is there and working. Also has to see it go out to see that the system has not signalled a fault.

 

Good luck for next weekend. Hope all goes well.

[Fourpot]

On 05/12/2020 at 20:31, V said:

My ABS on both Jeeps has been removed, but I am fairly certain that for an MoT pass the ABS light has to come on at ignition key turn and extinguish within 7 seconds. The tester has to see the bulb come on to prove it is there and working. Also has to see it go out to see that the system has not signalled a fault.

 

Good luck for next weekend. Hope all goes well.

Well the ABS light came on and then went out OK, so that's good. I've got an OBDII plug thingy with iphone app, so maybe that'll tell me if anything's not right. 

[frosty]

as long as the ABS light comes on, then goes off, you are good to go, as Vince said. 

[Fourpot]

It lives!

Finally got round to 'start day'. I went over everything I could think of to make sure it was all done up, topped up and ready. I put the engine oil in last minute (Royal Purple Break-in Oil), plugged my OBD2 gadget in (works blue-tooth to my phone - no codes, all seemed happy). 

Key in, ignition on, fingers crossed, turn starter....   It turned over.... and started! and... I shut it off within about 5 seconds as there was no oil pressure, absolutely none!. Fug! 

It's a new oil pump and I just put the oil in and checked the level, so first check is the sender. Nothing to see, except that oil had been pushed up it's spout, so there is some oil pumping happening. I had another sender unit, so used that one. 

Try again - Key in, ignition on, fingers crossed, turn starter....   It turned over.... and started! A little spluttery for a few seconds then smoother and running nicely. RPM taken straight up to around 2,000 to get strong oil pressure. I got the Mem Sahib to keep the revs up and stuck a wedge under the throttle at the engine end and kept the revs up.  Torch on and checking everywhere for leaks etc. A fair of smoke coming from somewhere, which I put done to grease burning off, but it was too persistent. I noticed a little puddle appearing on top of the inlet manifold and realised it was fuel!!  One of the injectors wasn't seated right and was leaking out. Engine off, injector out, replaced rubber seal.

Try again - Key in, ignition on, fingers crossed, turn starter....   It turned over.... and started!  Now I kept it running for a full half hour, keeping an eye out for leaks and watching the gauges carefully.  The new electric fan arrangement kicked in (nearly sucked me into the radiator) and works well - given that the engine is now running at the revs it'd be doing at 70mph, but standing still (albeit not under load).

Half hour done, switch off and drain the oil and take the filter off. Oil looks nice, no trace of metal or any sort of silveriness.  New filter on and fresh Royal Purple oil in.

Oil wise, that was an expensive half-hour...

That's it now until I've done everything else (which is a long list still) and I can get it ready for MOT and the road.

I was keen to get it's first start up and half-hour break in done soon after the engine was built, as the chap who did the block bore and clean etc. advised not to leave it standing for long with just assembly lube. But now I can take my time with the project.

 

Short video of it running (the light vapour from the breather filter is just a little damp coming out)....  https://www.youtube.com/watch?v=nOUG94K-xys

[frosty]

well done, a big milestone in your build.  

[spookie the aardvark]

Awesome mate that is so good to hear, an Xmas present to yourself (all i want for Christmas is ...................................... A running Jeep)

[V]

Congratulations on a successful first start.

Thanks for the tip on the Royal Purple Break-in oil.