4.6 crawler build - low end torque....

Project vehicle blogs or "mod diary" specific threads only.. Pics encouraged!!
User avatar
SkylinesSuck
Donator
Donator
Posts: 545
Joined: February 14th, 2009, 11:11 pm
Stroker Displacement: 4.6L
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Wrangler
Location: Northern VA

Re: 4.6 crawler build - low end torque....

Post by SkylinesSuck »

They all work now! :rockout:
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

To continue the build log...

I started to build adapter plate to adapt the bolt pattern of V8 4.7 throttle body to I6 throttle body bolt pattern.

Side effect is that I will also get this infamous 25 throttle body spacer that should (but proven not) bring some extra HP :doh:

Anyway - I started with 25mm (1") thick 7075 aluminum stock:

Image

I first marked one hole, drilled it an taped with M8 tap.

As usual - first hole always fit. Si I bolted it down firmly, marked and drill / tap the rest:
Image

Now to the sketchy part - the lathe. I wish I would not throw in that taper so early :huh: .

First 4mm center drill, than 13mm to make way for the boring bar. Sketchy.... But it went OK.

Image

Image

But it did work out just fin, I just had to bore out the hole on a slower pace, 1.5mm pass.

Image

In the end - it worked out just fine:
Image

Now to the mount bolt pattern....
°O|||||||O°
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

I went to see the 4.0 2002 TJ engine today.
Looks nice. But again different than the one I have....
It has new ignition system without distributor...
It comes complete with harness, gearbox etc...
I guess I can convert it back to distributor or is it a benifit to keep the new type of ignition?

BR M
°O|||||||O°
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Well, made some small progress on the build...

Opened up idle air passage on the new TB:
Image

and modified the linkage according to Martin's video. Only comment - when you bend the stop tab - you have to re weld it. Mine started to crack...

Than I moved over to 07120 head stripping. I made myself a tool using standard woodworker clamp and turned / milled an attachment:

Image

It went apart really nicely.

Image

Some valves are in great condition, some are slightly worn, especially exhaust valves.

I measured 0.02mm wear = 0.00078". Not knowing the way the head is bult and doing the window shopping at performance&spare part stores - I was looking for replacement valves and new guides. But - yes you are smiling now - there are no guides in the original head :shock:

Well, first american engine that I am working on in depth. 30 years older Alfa had dual overhead cams in aluminium head with bronze valve guides. Cast iron - OK, why not :-)

So, what are my options? Are there any oversize vales and that fit reamed guide bore? Machining for new those bought insert - not really an option locally as I have limited access to good machine shops.. One recommended by a guy who helped me on my C3 project - but also recommended to avoid this job...

HELP! Or shall I just by new exhaust valves and live it as it is?
°O|||||||O°
User avatar
SkylinesSuck
Donator
Donator
Posts: 545
Joined: February 14th, 2009, 11:11 pm
Stroker Displacement: 4.6L
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Wrangler
Location: Northern VA

Re: 4.6 crawler build - low end torque....

Post by SkylinesSuck »

Wow. Well, no help here but looking forward to hear what the experts have to say! Thanks for documenting your build though.
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Hi,

made some progress also today.

I did measure valve play, when extended 1" out:

Image

It reads roughly 0.15mm (0.006"). Is this still acceptable? I will most likely replace the valves so this value should also drop a bit...

Help ?

Than I tried my burs end other stuff I had in the shop to try to work on porting and smoothing out the rough edges and corners:

Ikea reading light came super handy :-)
Image

Image

OK. This looks like crap - I just tested different burs on the chamber... I will do better in the end:

Image

BR M
°O|||||||O°
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Hi guys, anny oppinions on those valves?
°O|||||||O°
Russ Pottenger
Strong Poster
Strong Poster
Posts: 889
Joined: August 15th, 2009, 1:27 am
Stroker Displacement: 4.7
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: 4.6 crawler build - low end torque....

Post by Russ Pottenger »

At a minimum are you planning on having the valve seats touched up and valves refaced?
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

At minimum for sure seats resurfacing. Valves most likely new, lapped to seal.
I just wandered if play in spec to keep the standard bores or do I need to fit replacement guides?
°O|||||||O°
Russ Pottenger
Strong Poster
Strong Poster
Posts: 889
Joined: August 15th, 2009, 1:27 am
Stroker Displacement: 4.7
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: 4.6 crawler build - low end torque....

Post by Russ Pottenger »

At roughly $70.00 to replace both intake and exhaust valves your probably smart to do that.

.0015 clearance for the intake and up to .0025 for the exhaust would be my recommendation.
Most importantly is to keep the contricity of the freshly ground seat to .001
Problem with alot of production shops is that they don’t stay on top of their equipment and there doing valve work with worn out pilots.
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Yep, strokers in my area - white bear in sahara :-)

I asked two head shops about rebuilding valve guides, and they say "we pop them out and press in new ones" and I say "no, you drill the hole and press in" and they say "you are probably wrong, the guides always pop out" :doh:

So, cast iron heads in european world of dual head cams in aluminium heads speak two different languages :D

So, I went to measure the play again, exactly next to stem/hole location, to determine the actual play.

I made a custom solid block holder for the 2micron dial (5x more precise than standard dial of 0.01mm):
Image

Then I measured the play:
Image

Image

It reads roughly something like 0.05 -0.06mm, Russ mentioned 0.038mm intake and 0.063 exhaust.

So I am out on Intake and close to OK on exhaust. With being the fact that valves on exhaust side are far more worn than intake, with max wear of 0.02mm:
Image

Image

So, I guess I will have to find a shop that can do it. Or a DIY job. I can have a pilot drill ground to exact specs locally by my friend, who produces industrial quality custom cutting tools within 0.005mm precision range.

And here is my long waited black friday purchase:

2002 TJ engine with less than 40.000 miles on it:
Image

Factory fresh walls:
Image :P
°O|||||||O°
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Well, I made some progress meanwhile.

First I laid my fingers on the horseshoe intake and bored the intake hole:

Image

I made a special jig to bolt on and guide the crown drill to be approximately centered....

When looking to the ports - i noticed that casting has huge restriction due to injector bosses feature:

Image

Image

Image

Of course it will be massaged even more as shown now. It was just testing my new electric die grinder :D
°O|||||||O°
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

Next I started to put a list together for the rotating assembly at Russ and we came to question of combustion chamber volume, overbore etc...

We came to conclusion od .60 over - so it will become a 4.7.

Than the dishing...

I can not use anything else but 95, 98 or even 100 octane gas here in Europe - so we decided to go with 20cc dish combined to 58cc chambers. Russ asked me to confirm volume - so I went measuring it. Here the fun begins :D

First - I bought a 60cc syringe (paid 50 cents for it at local drug store)

Image

I checked "calibration" with weight scale: 1cc = exactly 1 gram.

Than plugged the chamber, greased the valves and dropped them back in:

Image

And I have built a really nice cover plate of sheet of alu that I had under my bench:

Image

With vent and connection fitting custom made!

And then the shocking results:

Image

Image

51.5cc ! :?

It is the 7120 casting!

Image

So I checked with weight scale:

Image

Pretty darn close! And I got same results on two different chamber.

A lot of head scratching, half an hour bothering Russ on the phone, measurements ... :doh:

Well, a day later, I made a new plate, not so fancy, made just of piece of plexi, no special fixing.

Made a fill and I noticed quite a big air bubble trapped away from the vent. Drilled a set of holes and - bingo:

Image

58cc - spot on!

Thank you Russ for your patience with me :-)
°O|||||||O°
User avatar
SkylinesSuck
Donator
Donator
Posts: 545
Joined: February 14th, 2009, 11:11 pm
Stroker Displacement: 4.6L
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: Wrangler
Location: Northern VA

Re: 4.6 crawler build - low end torque....

Post by SkylinesSuck »

Thanks for the cc'ing write up!
TJryder
Making Progress
Making Progress
Posts: 86
Joined: July 29th, 2018, 1:03 pm
Stroker Displacement: 4.6
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: TJ

Re: 4.6 crawler build - low end torque....

Post by TJryder »

The further I get, more things I learn. That was the idea in the beginning :D

So, I approached intake manifold porting and port matching.

I had a neat idea of transfering the head outline to aluminum casting. So I took old shoe shine:
Image

diluted it with oil and grease:
Image

and smeared it on the head:
Image

and pressed the two together:

Image

And the result was terrible :doh:

So I went to plastic template route:
Image

Routed out the outline with burr:
Image

and scribed the lines across:
Image
°O|||||||O°
Post Reply

Who is online

Users browsing this forum: No registered users and 18 guests