Performance 4.0 down on power?

[gaz]

It only just occurred to me, who's timing set did you install? May be worth one more manufacturer phone call; a new set should only align at zero.

 

[limit_explore]

@gaz
i built the truck to race in ultra4 4600 stock class. this class requires us to maintain a factory block that was available for the make/model/year, no turbo no nos. other then that engine mods are unlimited. most everyone else runs a 4.0l Cherokee or a v8 grand Cherokee.

my goal is to have more all around power that is reliable (as silly as that sounds). id love to see 250hp at the wheels, but i am not sure how feasible that is i think 200 is more realistic. i have won a couple races purely on the reliability of the truck, so that is something i dont want to lose.

comp cams does put 4 degrees of advance into the 422, but recommends setting cam timing to 108 degees intake centerline for best performance. right now it measures 97 degrees (11 deg advanced)
as far as timing set i bought an ITM brand

 

[gaz]

With those flat tops and fast burn heads, I'm using:
• exhaust heat jackets on the headers and H-pipe
• 2 heat ranges lower plugs
• 15" electric fan
• engine oil cooler with remote filter
• all synthetic fluids
• 2 core Explorer automatic radiator
• rear of hood raised ½"

I agree with you, 200hp to the ground with a manual is a huge improvement over the stock setup. After transmission loss the stock is only about 138 @ the wheel.

If you still have it all apart, a complete bottom end balance, will net you an additional 10% efficiency. Also there are 3 different styles of Ford OHV 4.0l connecting rods; one of the three are 60g lighter each!

 

[limit_explore]

With those flat tops and fast burn heads, I'm using:
• exhaust heat jackets on the headers and H-pipe
• 2 heat ranges lower plugs
• 15" electric fan
• engine oil cooler with remote filter
• all synthetic fluids
• 2 core Explorer automatic radiator
• rear of hood raised ½"

I agree with you, 200hp to the ground with a manual is a huge improvement over the stock setup. After transmission loss the stock is only about 138 @ the wheel.

If you still have it all apart, a complete bottom end balance, will net you an additional 10% efficiency. Also there are 3 different styles of Ford OHV 4.0l connecting rods; one of the three are 60g lighter each!

im currently running:
-heat wrapped headers and y pipe (actually full exhaust has been wrapped)
-tr55gp plugs but if needed could definitely go to a different one if needed. maybe a quick dyno test for that?
-mechanical fan for the reliability (had a electric fan seize on my explorer while on the rubicon trail, it ended with a blown up radiator tank)
-3 core aluminum 4.0L auto trans radiator

i have the oil filter adapter to install a remote cooler if needed. wonder if i would need the high volume oil pump to efficiently supply a remote cooler and the engine......

believe it or not i am running the a4ld with a stage 3 kit from PATC. so far it has been a solid unit and allows for better rock crawling control since the truck does a combination of rocks and desert when racing. however id bet there is a bit more loss there even in 3rd gear. ive got dual remote coolers and the trans has never seen above 140 degrees.

 

[gaz]

An engine oil cooler works with either a hi volume or stock replacement Mellings oil pumps; I have used them under both conditions.

 

[limit_explore]

My thoughts was needing the high volume pump to push oil 6-8ft to the bed and back (where my trans coolers are mounted)

 

[limit_explore]

UPDATE:

parts came in.
new sohc pistons +1mm and ductile rings
all associated gaskets
a berret to measure combustion chamber cc w/stand

pulled heads and measured piston deck clearance. I got a measurement of .002" which means my deck has been milled MAYBE .001"
so unless Super six machined my heads .030-.040 I believe my pushrods are too short. i will be able to tell based off the cc measurement i get today.

now with the sohc pistons having a different compression height, they will stick in the cylinder .023"

question is, should i have my block machined .005 to reduce this?
should i have my heads milled? and if so how much can be removed before i have issues with lower intake manifold alignment?

 

[gaz]

@limit_explore
I WOULD LEAVE THE BLOCK AS IS
If you are measuring 0.023" clearance, that is a good thing. I recommend using the new pistons with the block as is. You are already going to be in the 11:0 arena with a race duty engine. It's nice to have the free horse power from the compression bump but it does come with a heat penalty.

My oil coolers are nearly 5 feet away from the engine outlet. It was never an issue with either the standard or hi volume Melling pumps. All that extra fluid sure is a bonus.

 

[limit_explore]

makes sense. basically where i am at with it.

so next question.. what do you think i should do about pushrod length?
now knowing my heads are not milled (measured at about 50-51cc stock should be 48, but they do bowl work when porting) and my block has not had material removed should i just order the 5.55" everyone runs when swapping in the 422 cam?

my compression ratio with un machined heads, 51cc chambers and flat tops will be 11.1:1 static, including the cam specs it will be 9:1, sounds like ill be running 91 octane from now on

 

[limit_explore]

update:
i called arp about rod bolts, the rep was a POS, and told me that they do not have an application for arp rod bolts and the 4.0 but also made sure to mention they receive at least one call a week looking for these bolts. IMO if you were receiving 52 calls a year for these, wouldnt you make and offer a set?

after comparing measurements, a 2.9L rod bolt kit is almost perfect match. so i ordered up a set of them and found they fit fine. .001" larger in diameter then what came out of my rods.

these will be going to my machine shop to ensure they are properly torqued, and re-sized before reinstalling (per arp requirements)

 

[gaz]

@limit_explore
1) I have a set of ARP rod bolts on my 4.0l piston Rods, I will did up the package and share the part number.
2) I would take the push rod measurement if 100% confident in it with +0.030" length for a reasonable guesstimate on lifter preload but no more than +0.040". If those are not available over the counter, then I would not hesitate to call upon Smith Brothers.

Could get a custom set made by The Smith Brothers or just spend the extra couple dollars and purchase their adjustable push rods...then your engine is set for the 200,000 miles.

 

[limit_explore]

ok some updates for yall!

Almost all parts are here. I ordered a custom set of 1.6:1 duration adjustable rockers, I believe thats all I am waiting on.

I had the heads shaved .012" to drop combustion chamber size from 53.5cc, now measures 50.5- 51cc. Ball honed cylinders, arp rod bolts installed and resized, flat tops on the rods.

I began gapping the rings last night and found the top ring measures within spec at .018" but the second rings are all WAY over spec at .025"+ on every ring. spec is 0.015-0.023 for both 1st and 2nd ring. I have reached out to hastings to get this issue sorted.

 

[limit_explore]

Engine is going together!

First issue was degreeing camshaft. Where the shaft was ground put me at 96 degrees instead of 108. Based on the math of 38 cam teeth divided by 360 degrees, each tooth should have been about 9.5 degrees. However when I retarded the cam one tooth it actually came out to 19 degrees due to the 2:1 ratio.
This meant i needed to make my own timing slot that would equate to half a tooth of movement. I decided to use the crank gear for this. The crank gear is hardened cast iron so welding it wasn’t the safest option in my eyes. Using carbide drill bits and carbide tap I drilled a hole in the gear for a m6 12.9 bolt which has exactly the same diameter at the shank as the keyway in the crank. I then tightened the bolt in using green lock tight (stronger then red) and cut off the

I reinstalled and degreed the camshaft. It came out at 105.5 degrees.. my hole was slightly off to the left. I was aiming for 106 degrees haha. Close enough and closer than 96 degrees advanced.

 

[limit_explore]

I then measured piston to valve clearance since I have the new 1.6:1 duration rockers, camshaft timed correctly, heads shaved .012” and flat top pistons.

Zero issues there. Installed heads and torqued to 110 ftlbs with 12.9 m10 bolts.

Custom rockers came in from Rocker Arms out of Redding, CA and I made the spacers. After installing I found I had issues with pushrod hitting the head so I ordered up some .060” and 0.030” valve shims. Ended up needing to use .090” total. Adjusted my spacers accordingly. All rockers have a brass bearing installed with oiling holes added to spray the pushrod cup. Very excited to see how these improve power!

I then buttoned up the top end including lower intake and valve covers. Bottom end is done minus rear main seal (can’t do that on the engine stand lol) I installed a Sohc oil pan for the built in girdle. Hoping it will clear the 4x4 cross member like I’ve read online.

 

[limit_explore]

well small update. engine is completely assembled, went to install engine last night and found 4.0 sohc oil pan does NOT fit in the 4x4 cross member even with 1/4" spacers on the motor mounts. I marked the crossmember where they come in contact and yanked engine out again. I will get some pictures tonight of how I am modifying it.