Building a New Stroker

[MarineJRM]

Well I have been searching diligently and so has my machine shop. Kinda sucks that I can not use the springs that came with the cam. I am going to be talking to Comp in more detail about that whole situation. They need to offer a kit A and a kit B for these cam setups if they are edvertising them to be for 4.0 setups. Maybe if enough people bitch about it they can use their resources to have someone manufacture new springs. For the time being I think that I am just going to go ahead and use the Mopar setup. I dont race my Jeep or anything like that to begin with I am just like most people that build these I want the extra torque and HP to turn the bigger wheels and bigger gear ratio when I get it in there.

Anyone wanna buy some Comp Springs?

[MarineJRM]

Well it seems that after going back and forth with Comp and where I baught my cam kit. I will be getting my money back on the "K" kit and am able to use that money towards the Mopar performance springs. After talking to Comp they will be more than likely doing something about this in the near future with so many people buying these kits for 4.0's and getting the wrong valve springs. An optional part number for the 242 vs. the 258's will be on the horizon. Yay for future stroker builders I will just be doing what everyone else had to and use the Mopar stuff.

[MarineJRM]

I wanted to post some great news. I have been working on this problem that we have been facing diligently. With the help of Paul Fink from Fink Motorsports and the Management at Comp. They are in the process of solving this problem with the valve springs and the 4.0 head. I spoke to Paul earlier today and he informed me that the manager at Comp that he spoke to is having the team get on it and find a resolution to this problem. Comp informed Paul as well that the Mopar springs are the WRONG springs to run with their cams. They will be getting back to me and Paul as soon as they come up with the answer even if it is them creating a new spring to correct this problem.

Needless to say I am happy. Just kinda sucks I cant put the rest of this thing together untill they solve the problem.

[SilverXJ]

They are in the process of solving this problem with the valve springs and the 4.0 head. I spoke to Paul earlier today and he informed me that the manager at Comp that he spoke to is having the team get on it and find a resolution to this problem.

It would be nice if they had a kit with springs that worked in the intended application. Last time I told someone NAXJA that springs wouldn't work he told me I was being negative.

Comp informed Paul as well that the Mopar springs are the WRONG springs to run with their cams.

Why? I had asked Comp and several other cam companies about using the MP springs, quoting spring rates and pressures, and no one ever said it was a bad idea to run them.

[MarineJRM]

The management informed Paul that the pressures were wrong and I believe he also mentioned to me when we spoke that the install height was wrong as well.

[MarineJRM]

Could someone tell me the brand and part numbers for the aftermarket valves that add a little bit of volume to the combustion chamber? I remember reading some where that someone used a set of valves that added a little volume to the chamber.

[MarineJRM]

Alright turns out that there is an answer to our problems. Atleast from Comp Cams. There is a fella there by the name of Mike who has tackled this problem and made the perfect answer to it. Honestly the easiest and best answer to it. He has a custom grind that he made up and it is the exact match to the Comp Cams product line. He took the 68-232-4 cam that I am using in my build and matched everything exact minus the lift of the cam. Everything else is exactly the same duration advance etc... I will be posting the cast number to request for my custom grind and anyone who wants to use a comp cam 68-232-4 will be able to order it. My hat is off to Comp Cams and Paul Fink from Fink Motorsports for helping me reach a great resolution to this problem. I am sure it took a little time to figure out how much to take off of the lift to make this cam work woth the 4.0L head setup. I think this will be a very good alternative to everyones builds and with Comp backing these cams and their quality of products we should be able to stroke it with alot less headaches and less of a dent in the wallet. Again I will post the part number to the cam as soon as I get it from them on Monday. Might not be the answer we wanted but if they offer it as a production part number in the future it will be pretty nice.

[SilverXJ]

Thats not really of a solution, but a band aid. Instead of addressing the issue of their springs not fitting, etc they opted to reducing the lift of the cam so you can use stock valve springs. Sounds just plain lazy. I guess it would work for a budget build.

A real solution would have been to find a spring, retainer, and lock combo that works on the 4.0L head and allow to use a cam with more lift, like the 68-231-4 or better if people are so inclined.

[Plechtan]

What exactly is the problem with using the stock reatiners? Is the diameter too small? Could the Stock jeep or Mopar retainers be modified by grinding to fit the Comp springs?

[lafrad]

Hmm.. I see that a bit differently.

Keeping the lift down to use the springs available could very well be an awesome solution.
DOes anyone have good flowcharts from the heads? Do they even GAIN any flow when reaching above 0.400" lift? if its already reached its max flow by then (or very close to it), you loose LITTLE if ANY performance by not opening further.

Also, to have the same durations for most of the profile, but not lifting the valve as much, means that the radius of the cam at the "peak" is much less aggressive... which is a good way to prolong cam life....

[dwg86]

Comp cams already makes a cam that will work with the stock springs. Part # 68-201-4, 212 @.050 dur/ .447 lift, 110 lobe centers. It actually sounds like a pretty decent torque cam.

I don't understand Comps descision about NOT making a new spring for the 4.0. I also think it's just a band-aid to the real problem. It would be nice to see a beehive spring made for the 4.0.

[MarineJRM]

I believe the reason behind not making a beehive spring is the VERY limited market for them. These springs were only available on the 242, 318 and 360 motors. Which have already been discontinued. For them to invest that kind of money into production of a new part for such a small market just wouldnt be equitable. I had to take a step back and think about it. Cams are such a small market to begin with, then to make extra parts for a market so small in the first place to go with your cams would be losing money in the long run. I do agree though a new spring would be a nicer solution but I think that the reduced lift is a good answer. The cam will run exactly like it would have with the after market springs. The stock springs will open the valve just as much and allow just as much air into the cylinder. Who knows though maybe they will make a spring eventually if they start selling alot of these cams. For my build though I think that this will work fine.

[Exos]

So, are you guys saying that my Mopar springs, that I installed and removed several times... are the WRONG springs?%

[MarineJRM]

I was told by Comp that they will work but are not what they reccomend for their springs. They even went as far as to say that they were QUOTE "kind of crappy and do not last very long". With that said when I last spoke to them I was all for the custom grind of the cam I want to use. If it does exactly the same thing and gives me the same performance I am all for it. I prefer to go with the manufacturers reccomendations on things like this. For me what it boils down to is what is going to last longer. If a little less lift makes it work its fine by me as long as the valve opens the same and the engine is breathing the same. It would have been awesome if they made a new beehive spring for the cam though.

[lafrad]

THere are plenty of beehive spring and retainer combos that work with the modern "stock" valve and lock parts on the market. Machining the head is NOT that difficult... as a matter of fact, its easy to do when the head is off. you get a quality beehive spring with favorable spring pressures, reduced valvetrain mass, and the ability to handle HIGH lift cams.... a win on all fronts. only "trouble" is machining the head. Its not expensive to buy the tool for your power drill... OR... a machine shop won't charge that much to do it for you.