Project "It's a Jeep Thing" - Huntr's 87 MJ Build

[Jesse J]

Jeez man that sucks

[scaleless]

4 hours ago, Huntr said:

They bored it to .040 over and it still has deep ridges

 

That's crazy.  My block was sitting outside with water in it for 4 years and cleaned up fine.

[Huntr]

Weird right? When I looked at the cylinders when I took it apart they looked pretty good to me. Could still see crosshatching on all the walls...

[Pete M]

smells kinda fishy, but oh well.  

[Jesse J]

On 5/13/2021 at 4:10 PM, Huntr said:

Weird right? When I looked at the cylinders when I took it apart they looked pretty good to me. Could still see crosshatching on all the walls...

 

13 minutes ago, Pete M said:

smells kinda fishy, but oh well.  

yeah it seems like anything they can't bore over would be very obvious just by looking at the cylinder walls 

[scaleless]

9 minutes ago, Pete M said:

smells kinda fishy, but oh well.  

 

That is what immediately came to mind when I read it - I thought some new guy bored it out too large and they tried to avoid responsibility.  Did they return your block?

[Huntr]

26 minutes ago, Pete M said:

smells kinda fishy, but oh well.  

 

12 minutes ago, Jesse J said:

 

yeah it seems like anything they can't bore over would be very obvious just by looking at the cylinder walls 

 

10 minutes ago, scaleless said:

 

That is what immediately came to mind when I read it - I thought some new guy bored it out too large and they tried to avoid responsibility.  Did they return your block?

I agree. They explained it as being gouges near the top of the cylinders where the ridges form. I could definitely see someone accidentally boring over the .03 I requested but I am going to hold off on judgement for now. They are a reputable shop that most people know of in the stroker world so I won't call them out just yet. I work in a machine shop currently so when I get my original block back I will check the bore size and report back. They are working with me on the price and not charging me for boring the first one since they are doing another one for me right now. 

 

The only other thing that made me question them was when I discussed freeze plugs with them today. They told me they would only press in steel plugs. They refused to do brass stating that they will leak and I would have to do it myself if I wanted them. Seems to go against everything I've read online. 

 

I will report back about the shop when I get my blocks back. Here's hoping everything else goes as planned and I'm not stuck looking for a THIRD block! 

[Huntr]

As discussed above I recently had to drop a second block off at the machine shop. To get the other block I pulled the original engine from the comanche and stripped it down. Pulling and engine/transmission/transfercase alone was...fun. Very doable but definitely took a few hours.  

 

Interestingly enough, this Comanche block has "BT" cast all over it. No one on the internet seems to know why. It's also got an AMC logo cast into it which is kinda neat. 

 

[scaleless]

6 minutes ago, Huntr said:

They told me they would only press in steel plugs. They refused to do brass stating that they will leak and I would have to do it myself if I wanted them.

 

That is ABSURD!  I've never heard a shop say that.  My local shop doesn't even do steel plugs unless you specifically request them because brass is such a cheap upgrade.

[Huntr]

2 minutes ago, scaleless said:

 

That is ABSURD!  I've never heard a shop say that.  My local shop doesn't even do steel plugs unless you specifically request them because brass is such a cheap upgrade.

Yeah, didn't exactly instill confidence when he told me that. I will be calling them in the morning to let them know I'll press in my own freeze plugs. Lets hope this bore/hone goes as planned. You guys are getting me all worked up! 

[Huntr]

Quick update on the progress. The last 2 weeks have been crazy hectic. The further I get into this thing the more it looks like it won't be done before I have to leave for training. 

 

I cleaned and opened up the AX15 that I got with the engine from the guy in Nevada. In typical fashion, I discovered that the trans case is cracked at one of the bracket mounts. It doesn't penetrate into the case itself so it still holds fluid. I debated TIG welding it but I don't feel like dealing with die cast oil soaked aluminum. Right now the plan is to leave it as is and not install a bolt in that hole. If it progresses any further and begins to leak I will replace the tail housing. 

 

 

While disassembling the gear train I managed to crack a few teeth on second gear. Guess that means I'll be ordering a new gear. One of the C-Clips that holds on the third gear syncrohub also decided to just shear down the middle. This c-clip is a select fit and has recently become very difficult to find. I ordered 2 different clips from Morris 4x4 hoping that one of them will be the correct size. If not, I will look into hopefully finding a clip off a R151 toyota trans or similar or calling around to different trans shops.

 

EDIT: Here is the correct snap ring: https://comancheclub.com/topic/66397-ax15-select-fit-snap-ring-3rd-gear-part/?tab=comments#comment-694291

 

 

 

 

 

 

And just because one engine swap isn't enough I spent my Saturday pulling an LM7 out of a Tahoe to swap into my buddies tacoma! 

 

[Huntr]

In better news I managed to find a horseshoe style intake and a factory style clock at the junk yard. I was way more stoked on finding the clock in good condition than I should have been! 
 
 
For the intake I will be using the newer style throttle body. I am still on the fence about boring it out, at the very least I think I will remove the tapper at the bottom and make it 63 mm throughout. I also machined a TPS adapter to adapt my renix style TPS to the new throttle body. It looks damn good if I do say so myself! Won't know if it actually works until I build the engine though...
 

 
 

[Pete M]

you got this  

[Huntr]

Been traveling and working the last few weeks so I haven't gotten around to making updates. Last week I drove down to California to visit some family and took the opportunity to swing by Russ Pottenger's place to pick up most of my stroker parts. Russ has been incredibly helpful so far and doesn't hesitate to answer all of my stupid questions. Below are the specs for my stroker build:

 

Jeep 4.2L 3.895" stroke crank
Scat 4.0L 6.125" rods

RaceTec +0.030" bore pistons, compression height 1.385", dish volume -18cc

CompCams 68-236-4 camshaft (Russ's custom grind)

Russ's Ported and valved 7120 head (Stiffer springs and larger valves)

0.051" Felpro Head gasket 

24lb/hr Bosch EV1 injectors

Horseshoe Intake

62mm throttle body

 

Should give me something close to these specs below:

 

[Huntr]

I also was able to get the AX15 put back together and mated up with the NP231. I got lazy and didn't clean them up enough to paint them. I figure when I get around to painting the actual Jeep I'll drop them and paint them.

 

I wrapped pretty much all of the wiring harness using the plastic wireloom like a lot of people have been doing. It looks great for now but I am a bit worried about the tape not sticking all that well over time. I also eliminated the C101 connector, lets hope I got it all correct so I'm not pulling my hair out when it comes time to fire the stroker. 

 

 

I threw together a super simple bed rack in my free time at work. I'm not crazy about the design but it was basically free material and the easiest design I could come up with due to my time constraints. I have a much more complicated design modeled up that includes a headache rack and small roof rack but I don't think I'll get the time to make it. As long as I have a spot to mount my tent right now is all that matters (Don't mind me using it as a scrap rack right now). 

 

 

Just waiting for a package from Summit containing my plastigauge, ring compressor/expander, and degree wheel and I'll be able to start assembling the block. I still need to measure for pushrods and decide what rockers to use. Right now I'm leaning towards just cleaning up my stock set. I'm also tempted to just buy a new set of stock stamped rockers for like $65... hmmmm

[MigglesYJ]

i help 

 

[Jeep Driver]

3 hours ago, Huntr said:

decide what rockers to use

See Harland Sharp, contact directly.

 

[Huntr]

See Harland Sharp, contact directly.
 

Those would be great but I don’t have the budget for over $450 on rockers right now

[Huntr]

Today I bored out the 60 mm throttle body to 60 mm straight through. There is a ton of misinformation out there on the benefits of doing this and many of them don't make sense. The biggest myth to me is that Jeep did this to "ease the acceleration and decrease bottom end power." From an engineering perspective this doesn't make much sense. Typically a taper is used to increase the intake velocity of the air to assist in charging the cylinders. More people just think more air = more power which is only a small part of the equation. I'm no expert in fluid flows so who knows. I figured that since I have a ported cylinder head with larger valves and and planning on doing a 2.5in exhaust, slightly increasing intake volume couldn't hurt. I guess we will see. 

 

[Pete M]

love the rack and it should do what you want, but I can't help but think about carrying a ladder or long board and it won't clear the roof.  maybe add adjustability into the next design?  although that might make it weaker.  I dunno.  I'm sure there's a way to have the best of both worlds.  

[Huntr]

35 minutes ago, Pete M said:

love the rack and it should do what you want, but I can't help but think about carrying a ladder or long board and it won't clear the roof.  maybe add adjustability into the next design?  although that might make it weaker.  I dunno.  I'm sure there's a way to have the best of both worlds.  

 

I agree with the loss of functionality but I was really aiming to keep the tent as close to the roof line as possible. The tent will basically take up the entire rack so there won't be room to carry much else anyways! 

[Huntr]

Engine and transmission are now connected and resting in the Jeep! It’s going to be a huge push to try and get it running before my deadline. I leave in 4 weeks for Texas and if it’s not done and running it’ll sit for the next 2-3 years! I ran in to trouble with the pilot bearing on the crank being the wrong outer diameter due to using a new style crank and old AX15 design. Ended up having to turn the bearing shell down on the lathe. The next hurtle is adapting the crossmember to fit the AX15. Hopefully I can just tap the 4 existing holes in the body and bolt it up.

[MiNi Beast]

Sweetness. 

[Huntr]

A couple years later and she runs! A couple months back at the beginning of March I had the engine running for the first time. It took a few hours of chasing down faulty sensors to get it to fire. It turned out to be a faulty CPS (of course). Once we got that sensor changed out it fired right up!  

 

 

 

For some reason I couldn't get it to rev above 2000 rpm. It would idle great and run fairly well right up to 2k then act like it was governed. It also smelled super rich leading me to think it was some fuel control issue. I tested every sensor I could, swapped the MAP, tried running it in open loop to eliminate the O2 sensor being an issue, nothing worked. At idle the timing seemed fine as well as all the way up to 2000 rpm. 

 

Fuel Pressure was a bit low for the 24lb injectors but since I'm running rich I don't think its an issue right now: 32psi w/ vacuum regulator; 40 psi w/out vacuum regulator. It holds a stable pressure through all RPM ranges. 

 

Vacuum also seems slightly low but no leaks that I can find I don't think its too bad: 14-15 psi at idle. 

 

I finally decided to reindex the distributor once again using cruiser's tip #13 . I had done it when I put the engine together but was starting to suspect that the ECU was advancing the timing too far ahead of the rotor causing spark to not reach the cylinders above 2000 rpm. I cut a window in and old distributor and aligned the rotor as close to the trailing edge as I could. Fired it up and it ran great!!! I guess I hadn't followed cruiser's tip close enough and hadn't set it close enough to the trailing edge. 

 

Next step is to get everything buttoned up to try driving it up and down the neighborhood. 

 

[Huntr]

Another issue that took more hours than I'd like to admit is finding a belt that would work with my setup. I'm running a renix block and accessory package with the horse shoe intake and new power steering pump/tensioner to match. This caused me to have to find a custom belt length. None of the ones recommended by different forums seemed to even be close so I don't know why my length is so different.

Here is what worked: 

 

6K994

Length: 99 7/8

Width 13/16