These "RV Cams". Advice on my planned build.

[coolwind57]

So, I bought a freshly-milled non-Renix HO 53008405 block.  It's bored .040" over.  I'm having the shop that I bought it from assembly the short block for me.

 

After discussing the build, I had asked my guy about the "RV Cams" I often hear about.  He said that they are usually referring to a Comp camshaft 68-232 and will give a bit more umph on the low end without an aggressive idle on these 4.0s.  This cam will run me 283 bucks.  In addition, I'll need to match the valve springs to this new cam.  He says I'll need "926" springs, at about 86 bucks for the set.  

 

I had also asked about whether I needed to upgrade the lifters and rockers as well.  He said I'd likely be fine with the standard Melling lifters but if it were him he's probably go with Mylift Johnson lifters.  Come to find out, they're only a few bucks more than Mellings.  I think he quoted like $115 or so.  He said he'd probably stick with the stock rockers and there's no real benefit for upgrading them for the money.  He also says that the timing chain being used works fine with this cam setup. 

 

So I think I'm going for this cam upgrade.  I don't do anything crazy with my truck as it's really just a truck that I drive to work and occasionally haul stuff around with.  Nothing crazy.  But I'm thinking I'll splurge a bit since we're all up inside the heart of this thing anyhow.  Why not have some extra power.  Total, this upgrade will run me about $500. 

 

He's also installing Silvolite coated pistons, which he says are a decent upgrade from stock pistons.  Rings are a slight upgrade as well, with top compression ring being chromed.

 

I'll be running a match ported Renix intake on a 7120 cylinder head from 1994.  Per Cruiser and 89MJ, I'll be using my stock Renix elecrical/timing components.

 

Anything jump out to you guys on this planned build?  I'm getting ready to pull the trigger.  Appreciate your input.

[ghetdjc320]

I’d double check the valve springs being used. The 926 springs are for the old 4.2 heads iirc. It may be correct but worth checking. I’ve run both the 232 and 235 cams. Both ran very well. I didn’t like the lobes on the comp cam being so narrow. Use proper high zinc oil. 

[coolwind57]

4 minutes ago, ghetdjc320 said:

I’d double check the valve springs being used. The 926 springs are for the old 4.2 heads iirc. It may be correct but worth checking. I’ve run both the 232 and 235 cams. Both ran very well. I didn’t like the lobes on the comp cam being so narrow. Use proper high zinc oil. 

Yea, he mentioned using a high zinc oil, non-synthetic which seem hard to find these days.  I was planning on Shell Rotella anyway, which should be fine from what I understand.  I'll double check on the 926 springs.  He was looking stuff up for me while on the phone as we spoke so its not all on paper yet.

 

What is your cam brand of choice?

 

Thanks for the input, Sir..

[ghetdjc320]

4 minutes ago, coolwind57 said:

Yea, he mentioned using a high zinc oil, non-synthetic which seem hard to find these days.  I was planning on Shell Rotella anyway, which should be fine from what I understand.  I'll double check on the 926 springs.  He was looking stuff up for me while on the phone as we spoke so its not all on paper yet.

 

What is your cam brand of choice?

 

Thanks for the input, Sir..

I had no issues with my comp cams. The 235 was my personal favorite. Still had a plenty smooth idle but more mid range torque. 
 

Rotella is good stuff but you can also add some zinc additive. If you ever find some stuff called “prolong” engine oil treatment, that stuff is a great additive for flat tappet cams. It’s typically a diesel engine oil additive. 

[cruiser54]

As of late, Comp Cams is having issues with quality. I'd do a cam, but not Comp anymore. 

[ghetdjc320]

There’s also the Mopar P4529229 cam. 

[75sv1]

     I recently did a mini stroker. Having issues with misfires. Still, on the rebuild, I went with Sealed Power pistons. They are the late style. Coated skirt and Hyper Eutectic. I used Hastings Moly ring set. On the camshaft, I had Schneider reground my camshaft. Also, has a coating or something for the lobes. At the time, no one was offering a 99+ camshaft. I redid my heads with Chevy Small block valves. I'd go with LS valves. One  of the heads I did, I used Melling valve springs for a 91-95 Jeep 4.0L HO. I think the specs are 90-ft-lbs at 1.640 lift. Should be good for 0.450 lift, possibly more. On LS motors, the stock springs are 90 ft-lbs at ???, for .495 lift up to around .550. 

      I'd use a break in oil, like Lucas for the initial 2000 miles. I plan to use Shell Rotela down the road. I see that they have a 10W-40 T6 out now.