4.0 Engine Toast - Considering Stroking

[mikalcarbine]

All of my crank bearings on my 2002 Jeep Wrangler's 4.0 are toast so I'm torn between two paths - replace it with a running junkyard engine for about $800-$1200 or rebuild my current engine and stroke it. If it go with the junker approach I'll likely rebuild my engine on the side and stroke it but that'll be over the span of a year or so.

I've seen some very simple "poor" man stroker builds that basically use the 4.2 crankshaft, rods + a few other goodies and keep the existing pistons. I haven't been able to come across and full parts list with pricing for the entire job. I think I'd need to replace all of my bearings (camshaft, maybe lifters I don't know yet). If I go down the stroking route I wouldn't want to spend much more than $1500 total (I'm willing to do the hunting for the best deals and cheapest places to find parts).

My other largest concern about stroking is being able to run 87 octane without any issues. From the research I've gathered this is determined by compression ratio but mostly how close to stock one's "quench" (distance from top of cylinder at TDC to top of block). Does anyone know any builds that will be relatively cheap while allowing for 87 octane? I'm looking to do a lot of low speed rock crawling with this rig, not much high speed stuff

[Cheromaniac]

My other largest concern about stroking is being able to run 87 octane without any issues. From the research I've gathered this is determined by compression ratio but mostly how close to stock one's "quench" (distance from top of cylinder at TDC to top of block). Does anyone know any builds that will be relatively cheap while allowing for 87 octane? I'm looking to do a lot of low speed rock crawling with this rig, not much high speed stuff

Sounds like you'll be choosing between these two recipes:

4.6L Low-buck, low CR "rockcrawler"

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Silvolite UEM-2229 +0.030" bore pistons
Increase piston dish volume to 30cc
8.75:1 CR
CompCams 68-115-4 192/200 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.035"
Mopar/Victor 0.043" head gasket
0.058" quench height
Accel 24lb/hr injectors for '96-'04 engines

4.6L modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black UEM-IC944-020 forged pistons
9.25:1 CR
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.070" quench height
Accel 24lb/hr injectors for '96-'04 engines

HP/TQ outputs will be similar from both engines. The modified "poor man's" will be the simpler, cheaper build while the "rockcrawler" will run on 87 octane without breaking sweat.

[mikalcarbine]

Excellent, I was hoping you'd reply, you seem well known on this forum. I'm going to start pricing out both builds and go from there. To save me hassle (I'm not being lazy) do you know if anyone has any excel sheets with a BOM that have already been through all this?

For more background here is my thread on WF showing some pics of my current crankshafthttp://www.wranglerforum.com/f5/zero-oi ... 44238.html

My rod bearings are at 0.003" and my mains are around 0.002" (just measured with plastigage 10 minutes ago), both within spec. I'm very tempted to try to polish my rod journals in place and run new bearings but as suggested my cam bearings could be toast as well, it'd be a large gamble of money that I could put towards this rebuild

[mikalcarbine]

I'm halfway through an excel sheet, I'm totaling a little for $1,000 which doesn't include a lot of the rebuild parts I'd need (full gasket set, etc), machine work or tools. Unless I can rent, I think tools might set me over the edge. Here's my current list

https://docs.google.com/file/d/0B-Cln7F ... sp=sharing

The big unknown is I won't know exactly what I'll need until I open up my engine (lifters, bearings, studs, etc)

[jsawduste]

I DO NOT like the Poormans stroker with today's USA blended fuels.

Dino and myself have argued this for a long time.

[Cheromaniac]

I DO NOT like the Poormans stroker with today's USA blended fuels.

Dino and myself have argued this for a long time.

The modified PM stroker has a lower quench height than my original PM stroker, a slightly lower quench height than a stock 4.0, and only a 0.4:1 higher SCR than a stock 4.0, so why wouldn't it work with today's USA blended fuels? A stock 4.0 runs on 87 octane so surely a modified PM stroker will be able to run on a lower grade of fuel than premium.
I know you're sceptical about this John and you're entitled to disagree.

To save me hassle (I'm not being lazy) do you know if anyone has any excel sheets with a BOM that have already been through all this?

Not an Excel sheet but a comprehensive parts list:

http://www.angelfire.com/my/fan/parts.html

Bear in mind that I built my engine 9 years ago so parts were a lot cheaper back then.

[mikalcarbine]

Well, I guess I'm committing, just purchased a 4.2 crank and 707 rods from a fellow jeepster in Alabama for $185 shipped. He said the crank is from a mid 80's CJ, this is the 4 counter-weight version right?



He should be shipping it today/tomorrow.

I'm starting to lean towards saving up slow and doing this build right (i.e. spending more). I'm going to start putting a few build together and compare them cost vs performance wise, pick a goal and go for it. Are there any benefits to buying an entire rebuild kit vs piecing everything together (bearings, timing chain, gaskets, etc)?

[SilverXJ]

Yes, that is the 4 counterweight version.

The benefit of buying a whole kit is that it is easier and sometimes cheaper. Neither equal better.

Research and buy your own part. You can cherry pick what you want and not have to guess as what you are getting.

[mikalcarbine]

Ok so after many hours of research I've compiled my first draft build list, the cost is pretty daunting and I know I'm still missing items...

See the excel sheet on my public google drive here (feel free to insert comments!). I'll keep updating it daily until I feel it's right

https://docs.google.com/spreadsheet/ccc ... sp=sharing

A few questions:

• 1. I've heard Compcams camshafts aren't to reputable, could anyone recommend a similar camshaft for this build? I am also considering kicking the build up with a higher CR/more aggressive cam and running 91/93. If I'm going to spend this money I might as well get the best performance out of this thing. I might make a separate build sheet for this direction and compare total costs between the builds
  
  2. Is JP Performance *the* brand to get for the timing set. I know I definitely want double roller, I've heard Rollmaster or Cloyes are also great brands, Cloyes can be had for cheaper
  
  3. I'm unsure of what the cam bolt/washer are for. Will I need it with my original 4.0 block?
  
  4. Think it is worth spending money on a new harmonic balancer or to reuse my existing?
  
  5. Any particular recommendation for freeze plugs?
  
  6. Is it recommended to purchase new rockers/bridges/pivots or can I reuse mine?
  
  7. I'm torn between sticking with the low buck low CR build or going all out. If I stick with the low buck low CR can I get away with reusing my head components and pushrods (I'm assuming new pushrods will be required if I am milling the block/head)? This would save me an estimated $450.00
  
  8. I used Muad'Dib's estimates for machine labor, the total is over $1,500! Since my engine is fairly new and in good condition are there certain things I can skimp on safely? Keep in mind I'd rather spend the money to do things right the first time
  
  9. For $3,500 for a serious build I'm highly considering just buying a Golen, opinions on this?

[Cheromaniac]

A few questions:

• 1. I've heard Compcams camshafts aren't to reputable, could anyone recommend a similar camshaft for this build? I am also considering kicking the build up with a higher CR/more aggressive cam and running 91/93. If I'm going to spend this money I might as well get the best performance out of this thing. I might make a separate build sheet for this direction and compare total costs between the builds
  
  Good idea.
  
  2. Is JP Performance *the* brand to get for the timing set. I know I definitely want double roller, I've heard Rollmaster or Cloyes are also great brands, Cloyes can be had for cheaper
  
  Just get the Cloyes set from summit racing. They have the best pricing.
  
  3. I'm unsure of what the cam bolt/washer are for. Will I need it with my original 4.0 block?
  
  Yes. Your 2002 block was designed to use a thrust plate to retain the cam, and that isn't compatible with any of the aftermarket cams nor any of the aftermarket timing sets. You'll definitely need the '98 and earlier recessed cam bolt/spring/pin with larger washer when using an aftermarket cam and timing set.
  
  4. Think it is worth spending money on a new harmonic balancer or to reuse my existing?
  
  Unless it's fairly new, replace it.
  
  5. Any particular recommendation for freeze plugs?
  
  Doesn't matter as long as they're brass 'cause they won't rust.
  
  6. Is it recommended to purchase new rockers/bridges/pivots or can I reuse mine?
  
  You can reuse them if you're going for a cheap build with a stock or mild aftermarket cam. If you're going for a more aggressive build I suggest you opt for roller rockers.
  
  7. I'm torn between sticking with the low buck low CR build or going all out. If I stick with the low buck low CR can I get away with reusing my head components and pushrods (I'm assuming new pushrods will be required if I am milling the block/head)? This would save me an estimated $450.00
  
  Yes
  
  8. I used Muad'Dib's estimates for machine labor, the total is over $1,500! Since my engine is fairly new and in good condition are there certain things I can skimp on safely? Keep in mind I'd rather spend the money to do things right the first time
  
  Depends on your budget and how far you want to go with the build
  
  9. For $3,500 for a serious build I'm highly considering just buying a Golen, opinions on this?

Golen's reputation is generally good but if it was my choice, I'd rather choose the parts that I want in my stroker and see it coming together. It's also more fun than buying one ready made.

Keep in mind that if you reuse your stock cam (with new lifters) you can also reuse the stock timing set (as long as chain deflection is less than 1/2"), valve springs/retainers/keepers, pushrods, and rocker arms saving you a big chunk of change. Unfortunately the engine will also make less horsepower so it's up to you.

[SilverXJ]

• 1. I've heard Compcams camshafts aren't to reputable, could anyone recommend a similar camshaft for this build? I am also considering kicking the build up with a higher CR/more aggressive cam and running 91/93. If I'm going to spend this money I might as well get the best performance out of this thing. I might make a separate build sheet for this direction and compare total costs between the builds

Lunati, Isky, Bullet, Clay Smith, etc. All make good cams. I would recommend getting in contact and ask for a custom cam.

2. Is JP Performance *the* brand to get for the timing set. I know I definitely want double roller, I've heard Rollmaster or Cloyes are also great brands, Cloyes can be had for cheaper

JP = Rollmaster.

3. I'm unsure of what the cam bolt/washer are for. Will I need it with my original 4.0 block?

You will need the cam bolt, washer, pin and spring to go with the camshaft and timing set you go with (earlier vs. later). I also recommend replacing the goofy stock pin and spring setup with a solid pin and set cam endplay manually.

4. Think it is worth spending money on a new harmonic balancer or to reuse my existing?

Reuse if in good condition

5. Any particular recommendation for freeze plugs?

brass if you can find them.

6. Is it recommended to purchase new rockers/bridges/pivots or can I reuse mine?

you can reuse if in good condition.

7. I'm torn between sticking with the low buck low CR build or going all out. If I stick with the low buck low CR can I get away with reusing my head components and pushrods (I'm assuming new pushrods will be required if I am milling the block/head)? This would save me an estimated $450.00

You may, but you would need to check preload. Custom length pushrods are fairly cheap, about $80/set.

8. I used Muad'Dib's estimates for machine labor, the total is over $1,500! Since my engine is fairly new and in good condition are there certain things I can skimp on safely? Keep in mind I'd rather spend the money to do things right the first time

Not really.

9. For $3,500 for a serious build I'm highly considering just buying a Golen, opinions on this?
[/list]

Golen is good as is ATK.

[mikalcarbine]

Thanks all,

I haven't pulled my camshaft yet but I have concerns it has some funny wear. I originally toasted my rod bearings from pulling water/silt into the engine crankcase through leaking seals so I'm worried more may be damaged. I started a build thread that details some of it here: http://forum.northeastjeep.org/index.php?topic=30815.0

Taken from my other thread:

My lifter push rods all had something coating them at the same height, I'm thinking this was water/oil residue, it wiped off no problem



Some of the same muck that was in my oil pan was floating on top of these bolts


Here's a bunch of shots of my cam lobes









The wear looks funny and some of the cam lobes look like their starting to flatten, I don't know to which extent is normal

Something doesn't look entirely kosher with my oil pump drive gear, it looks like a few teeth on the camshaft side gear are chipped





I guess I'm not too sure if I'd want to reuse the cam, I'll likely pull it this/next week and post some pictures. Could someone recommend me a 1) mild came in which I could use stock head components and 2) an aggressive cam if I wanted to install mopar performance springs?

On another note, I received my crank and 707 rods from the guy I bought them from in Alabama. The box came all mangled from shipping but it was packed well and looks ok. However I think someone tried to chamfer the oil holes in the crank at some point, what do you guys think















Not sure what I'm looking at here, if I got screwed or not. The journals are otherwise in good condition minus those rust spots.

[SilverXJ]

The cam is showing some wear and scuffing, not sure I would like to reuse it. I don't see and issue with the oil pump drive gears. Closer picture would help though. That bevel on the end of the tooth is normal.

The crank is used, hoping you knew that. It would at least need a polish.

[mikalcarbine]

Yes I knew the crank was used and was expecting at least a polish/grind, does it look like someone tried to chamfer the oil holes? I'm looking at several options right now in descending "most likely to occur" order

1) 4.5L Low Budget with Standard Bore
2) 4.6L Poor Mans (keep stock head, replace as little as possible and run stock/mild cam)
3) 4.6L Low Buck or Low Buck Low CR more agressive cam
4) Rebuild as stock

I still need to price out each build and go from there along with pulling my existing engine apart and inspecting what components might be reusable (rockers, timing gear sprockets, camshaft, etc). I should have a list brewed up in a few days when I get some free time

[mikalcarbine]

Going to break down my engine this weekend so a machine shop can check my block.

I noticed yesterday my head is 0331



I never overheated the engine but I'm very hesitant to put ANY money into this head. I'm not too sure what to do with it, I'd like to port and polish whatever head I end up using in the end. Should I break the entire head down and have it hot tanked and magnafluxed and then go from there? Would I be able to reuse stock components doing this or should I just let everything be and ride on it if the components are within spec?