Help with 4.6 stroker rebuild after failed cam gear

[Muad'Dib]

Eliminating that goofy factory spring setup is a good idea.

Seems to work fine on stock 4.0 engines for 300+k miles so I don't think that's the issue here.

But are we not talking about non-stock engine set-ups here? Just because it worked with a stock motor doesnt mean it will with a performance motor with higher Spring pressures etc.

Granted my current stroker is using the old button spring set-up and its working fine, but i dont things are created equal here which is what your statement leads someone to believe.

[SilverXJ]

Typically in our builds the valve springs are changed, the retainers and locks are changed, the cam is changed (lift, duration, tapper, rate, etc), the timing chain is changed, the lifters are changed, oil pump is changed, and occasionally the valves. There is nothing stock about the the valve train any more. While maybe the pin and spring setup can control the stock setup it isn't up to par for modification. If the cam is in fact walking, then what controls that? The only reason I can see why the factory went with the spring setup is easy of assembly. Slap it in, throw the cover on and roll. Using a solid type takes a bit more work to set correct end play. There is no reason to use the pin and spring when doing a build.

[Retlaw01XJ]

Using a solid type takes a bit more work to set correct end play.

Silver, what would you consider correct end play?
I read you had 0.005" on one of your builds. I ended up with 0.014" with a solid pin and am wondering if that is too much.
I'm also concerned the cover may wear and cam end-play will increase over time.
I like the idea of the delrin button vs the steel pin... less wear on the cover?

There doesn't appear to be much room between the cam bolt and cover. The pin seems to be recessed from the bolt face, with the nipple on the cover protruding beyond the bolt face to the button....Is enough fore-aft movement even possible to cause excessive wear on bearings and chains?

I'm gonna speculate and say the ultimate solution would be for the cam manufactures to use the late cam core with the cam-retention plate. Opinions?
Here are some pics of my 2001, Are other years similar?

[SilverXJ]

Silver, what would you consider correct end play?
I read you had 0.005" on one of your builds. I ended up with 0.014" with a solid pin and am wondering if that is too much.

I would like to see .005-.010" .014 should be ok though. I just researched and went off some other engines since there is no spec for ours.

I'm also concerned the cover may wear and cam end-play will increase over time.
I like the idea of the delrin button vs the steel pin... less wear on the cover?

I am concerned with cover wear too and will be keeping an eye on it. The derlin button would wear the cbver less, but the button may wear more.

There doesn't appear to be much room between the cam bolt and cover.

There isn't much room, but enough room for the cam to move forward around 1/8"

The pin seems to be recessed from the bolt face, with the nipple on the cover protruding beyond the bolt face to the button....Is enough fore-aft movement even possible to cause excessive wear on bearings and chains?

The pin should protude from the bolt face, not be recessed. Was that pic taken with the stock setup?

I'm gonna speculate and say the ultimate solution would be for the cam manufactures to use the late cam core with the cam-retention plate. Opinions?

That would be nice, but they are leaving out the earlier years unless they want to drill and tap. Also there isn't a performance timing set for the plate style.

[Retlaw01XJ]

There isn't much room, but enough room for the cam to move forward around 1/8"

The pin seems to be recessed from the bolt face, with the nipple on the cover protruding beyond the bolt face to the button....Is enough fore-aft movement even possible to cause excessive wear on bearings and chains?

The pin should protrude from the bolt face, not be recessed. Was that pic taken with the stock setup?

I'm gonna speculate and say the ultimate solution would be for the cam manufactures to use the late cam core with the cam-retention plate. Opinions?

That would be nice, but they are leaving out the earlier years unless they want to drill and tap. Also there isn't a performance timing set for the plate style.

I checked my clearance by moving the cam gear forward a bunch (solid pin installed) 0.150"'++, then bolting on the timing cover to push the cam back, removing the cover, and measuring the cam-gear-to-block clearance....reduced to 0.014" I kept cutting the solid pin to a shorter length.. went a bit too far last cut. Maybe I should recheck that clearance with clay to ensure the clearance is at the center point of the pin ??

If we figure 1/8", or 0.125" the max play between bolt and cover ...maybe that amount of movement affects the oil wedge on the cam bearing.... and possibly leads to failure? The stock spring setup apparently allows that much since there is no 'stop'....

You went with a bearing setup? That sounds like the best solution.

Apologies to kkchevy3...I' don't mean to hijack your thread, but I think this will be revelent to both of us....

[Antifreeze2]

Has anyone tried just using a slightly longer pin for increased spring pressure?

[kkchevy3]

no keep going guys lol. i see on 505 performance site they list they use a custom cam button or something like that. I think i might give them a call and see what they mean by that.

[Cheromaniac]

Typically in our builds the valve springs are changed, the retainers and locks are changed, the cam is changed (lift, duration, tapper, rate, etc), the timing chain is changed, the lifters are changed, oil pump is changed, and occasionally the valves. There is nothing stock about the the valve train any more.

You might recall that when I first built my stroker I didn't have a stock valvetrain either. I used the Crane 753905 cam, Crane lifters, Mopar 5249464 springs with matching retainers/locks, and the stock recessed cam bolt with spring/pin. After 34k miles, one cam lobe (no.6 intake) and two lifters (both no.6 cylinder) failed but the other cam lobes, all cam journals, and remaining lifters still looked immaculate. The dizzy gear had a normal wear pattern and the cam gear/cam bearings/timing set were like new. There was nothing to indicate a cam walking problem. Then again, the pin was long enough to protrude from the cam bolt in my case so it was resting against the nipple inside the timing cover.
I've been running the stock cam and valve springs for the last 33k miles since the mini-rebuild using the same timing set and cam bolt.

[SilverXJ]

no keep going guys lol. i see on 505 performance site they list they use a custom cam button or something like that. I think i might give them a call and see what they mean by that.

If you do I would be interested in what their solution is.

Has anyone tried just using a slightly longer pin for increased spring pressure?

That may work, maybe just a long enough pin to almost completely compress the spring with the cover on. But then how much would be too much pressure?

You went with a bearing setup? That sounds like the best solution.

Its not a full bearing, but rather a roller from a roller style bearing.

If we figure 1/8", or 0.125" the max play between bolt and cover ...maybe that amount of movement affects the oil wedge on the cam bearing.... and possibly leads to failure? The stock spring setup apparently allows that much since there is no 'stop'....

That is one of the theories behind my bearing failure.

You might recall that when I first built my stroker I didn't have a stock valvetrain either.

Ok, so it worked for one instance and one combination of parts.

[kkchevy3]

so i called up 505 and spoke to the guy there. seemed to know his stuff. he suggested i go with this kit. he mentioned hearing a bunch of problems with comp cams. he says they use a luniti cam. here the listing comes with everything. says they havent been having any problems and this cam will work better with my setup? http://www.ebay.com/itm/Performance-Jee ... 64#vi-desc

[geib05]

Don't have any technical advice to offer to the situation, but if you decide to go with the same cam, I just posted a brand new one for sale on the forum.

[Cheromaniac]

Ok, so it worked for one instance and one combination of parts.

It's probably working fine for many other home built strokers plus Hesco and Golen. It's likely that the spring will fatigue as it ages and the pin will also see some wear so when replacing the timing set, it might be a good idea to use a new cam bolt/spring/pin.

[kkchevy3]

alright well looks like im just going to order a new cam button/ bolt/ spring. now on the subject of picking a new cam. I kind of have a bad taste in my mouth for comp cams. The 68-232-4 is what i had. Seemed to work fine with the exception of mild pinging on hot summer days on highway under load with premium (which i figure i can fix with polishing the combustion chambers). Any cam suggestions?
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black UEM-IC944-030 pistons
9.6:1 CR
CompCams #68-232-4 206/212 degree camshaft
Mill block deck 0.020" NOT Sure on this one
Mopar/Victor 0.043" head gasket
Ford 24lb/hr injectors
264hp @ 4900rpm, 324lbft @ 3500rpm

[SilverXJ]

You would want a cam with a longer duration/more over lap to lower the DCR. You will lose a bit bottom end torque, but gain HP up high. More of a street cam. I had a custom cam from Isky that I liked, but they take a while to get it done. The Hesco cam I have now runs good, but I don't think the PCM likes it much. However, with the KB 944 pistons you should be able to run premium and not ping.

[6TIME]

One of my 4.0's went 76k before losing a lobe on a Comp 232-4 stock with stock cam retainer setup. I think that there is a small instance of situations out there where camwalk might be the actual problem... Silver's saga was one of the most convincing I've seen yet, It'd be nice to see some concrete evidence tho.. I have built 4 4.0's all with nothing stock about the valvetrain with no abnormal issues other than losing a lobe on the cam due to crappy oil. I'm on stroker #2 now due to cam bearing failure...But, I'm convinced that my bearing failure was due to sandpaper like cam journal finish and not camwalk..... Lunati's Voodoo line are some the best lobe profiles out there......quiet, but they still get the duration and lift.. I've been very impressed with the Voodoo's in sbc's and the one in my stroker as well... With any cam that you purchase, make sure you closely inspect the journal finish, dist gear, and lobes. There has been some quality control issues with aftermarket cams and acceptable journal surface. I had to learn the hard way.
Good luck