Need Help Finalizing 4.6L Stroker Recipe

[Stone43]

I'm swapping out the motor in my 97 Cherokee XJ and using a 1999 motor (doesn't have 0331 head) that I pulled from a pick n pull. My goal with this stroker build is to build a powerful motor without sacrificing reliability. Reliability of the motor is the most important thing that I want to maintain, this is why I elected to build a stroker with a 8.8:1 C.R.. I've read the majority of the threads on this forum, but I still having some trouble finalizing the stoker recipe that I want to go with. Thank you in advance for any of your help/advice.

I currently already ordered these parts:
Clegg Engine Stage II Stroker Kit 8.8:1 C.R.
Icon 4032 Forged Dish Pistons
Perfect Circle Moly Piston Rings
King Main and Rod Bearings
Scat Enterprises 9000 Series Performance Cast Steel Crankshaft 3.895” Stroke
Reconditioned Connecting Rods 6.125"

I was going to order:
62mm bored throttle body
Flowkooler Hi Flow Mechanical Water Pump
Mopar Performance Head Gasket 0.043" Head Gasket
Melling Freeze Plugs
Melling Oil Pump
Felpro Rear main Seal

The parts that I have had trouble deciding on are:
Was thinking about using the stock crankshaft after reading all the threads on here, and the reliability issues with aftermarket cams
Fuel Injectors? Was thinking about using Bosch 24lb/hr EV1 Injectors
Headers?
Also will I be able to use the fuel rail off my 97 block on the 99 block I'm building (The fuel rail on the 99 is broken)
Lifters?
Cam Bearings?
Please let me know if there is anything that I should consider changing or adding to the build.

[gradon]

The 97 fuel rail is the same as the 99. You can re-use the stock camshaft with new lifters, but I'd get a bigger lift cam. Find a header with at least a 2.5" outlet. Those 24# injectors will work.

[Russ Pottenger]

Looks like you have the majority parts already ordered.

I'll offer a few of my thoughts and opinions.
Not a big fan of full dish pistons on normally aspirated engines that utilize heads with a closed, or partially closed combustion chambers. Your losing some of the combustion efficiency by eliminating the potential quench area.
The solution would be to buy a slightly more expensive custom piston, (about $75.00 over the cost of the Icon's.)
Some company's, Mine included, will have them in stock and ready to ship in the near future.
Another option would to run the 944 pistons and do some chamber work.

Allot talk and bad information givin on aftermarket camshafts lately. I'll share some of my thoughts.
Some of this relates to a lack of understanding on how a flat tappet camshaft works. Most all of us are aware of the rapidly growing problems of camshaft failures, or cams going flat. Allot of the blame can be attributed to the reformulation of the additives in today's current engine oils. The second culprit is improper camshaft break in procedures, but many believe the problem is because many of the aftermarket cams have narrower lobes than the factory OEM cams.

All flat tappet camshafts have taper on the lobes, and their corresponding lifters have a slight crown on the bottoms. If you look down the lifter bore you'll see that the cam lobe is off center to the centerline of the lifter bore. The reason for that is its absolutely necessary that the lifter spins in the bore as it moves up and down. if were to stop for even a moment it would cause a failure immediately. For the lifter to adequately spin it relies on a narrowed tapered contact area.
A wider lobe in the center of the bore would have a negative affect.

A few things on consider and think about.

Russ

[biscuit]

very interesting point on the offset of the cam to the lifter. giving that the aftermarket cams are about 30% narrower on the lobe, would that mean that the wider lobe would only be 15% closer to center of lifter? spreading of the pressure on the contact point seems beneficial, as long as it does not inhibit the spinning of the lifter. by wider lobe, i am meaning the stock width of a stock cam.

[stroked'73]

Dino got similar results with a stock cam as the aftermarket one he was running.

[stroked'73]

Here's a thread on it .....
(Dino / Cheromaniac's reply is about halfway down the first page.)

http://www.jeepstrokers.com/forum/viewt ... 530&hilit=

[Cheromaniac]

very interesting point on the offset of the cam to the lifter. giving that the aftermarket cams are about 30% narrower on the lobe, would that mean that the wider lobe would only be 15% closer to center of lifter? spreading of the pressure on the contact point seems beneficial, as long as it does not inhibit the spinning of the lifter. by wider lobe, i am meaning the stock width of a stock cam.

The lobes are 2/3" wide on the stock cam and 1/2" wide on most aftermarket cams. I don't know why the aftermarket guys chose to go with narrower lobes but given that most of these cams also require upgraded valve springs, more spring pressure on a narrower lobe doesn't sound like a good recipe for longevity to me. Add low ZDDP oils to the mix and it becomes a recipe for early cam/lifter failure instead.
I'm at 80k miles on my stroker with the last 46k miles on the stock cam & valve springs.

[MtPockets]

I'm at 80k miles on my stroker with the last 46k miles on the stock cam & valve springs.[/quote]

I'm early in the process of planning a stroker, and still trying to learn what I can about them.

I was just wondering why you apparently changed out an aftermarket cam after only a few miles?
What cam came out, what went in, and what was the overall effect of the change?

Thanks for the info!

Ron

[Cheromaniac]

Unfortunately one of the Crane lifters (no.6 exhaust) that I used in the original build collapsed, and the spring from that lifter got stuck in the adjacent lifter bore (no.6 intake) preventing that lifter from rotating. The second lifter became cupped and flattened the corresponding lobe on the Crane 753905 cam that I'd used. Shame 'cause the rest of the cam still looked perfect after 34k miles.
Luckily I still had my original '92 cam as a spare, which was still in great condition, so I swapped that back in together with a new set of Crown Automotive lifters and my original OEM valve springs. The reduction in engine power and performance was barely even noticeable.