would you like roller tipped rockers for your 4.0?

[SteveVB]

OK Im looking for anyone interested in rocker arms for their 4.0.

Im looking to see if there is interest in getting some roller tipped rockers made for the 4.0 V-6.

What is it? Im looking at a roller tipped aluminum rocker. It would have a bronze pivot bushing and use the stock shaft. Ratio 1.6 (or actually any ratio can be made). This will take a while to get going and get the work done so a time frame in months is to be expected. Cost $300 + .

Why would you want these?
1. increased ratio over stock. the stock ratio is 1.46 by changing to a ratio of 1.5 or 1.6 your cam gets bigger by about 10% without tearing into the engine.
2. the roller tip eliminates the wear on the valve stem tip, and rocker arm.
3. the roller tip reduces the side loads on the valve increasing guide life.

This isnt a group buy(yet) but Im am looking to see if their are 20-25 interested to get this done, so if you are interested either e-mail me or post here. I am still getting details on what can be done and I will post any updates as I get them.

 

[Michigander]

Sorry I don't know much about these things, so I have a few questions

Does it give HP and torque gains?? How much gains should we expect? What else do I have to modify to use this?

I would considered doing a mod for 300+, but I need to know more about it

 

[BRacing]

I have experience with these in race applications, and have never tried them on the street. Here's why...

Have you seen your 4.0 valve covers? Look how hard they are to get to. You have to be able to take the covers off to install the rockers. Then, you must know how to adjust the rockers.

Roller Rockers have a few moving parts, as opposed to the stamped rockers that come factory. These moving parts (the roller tip) help reduce friction. However, if they are not correctly made, the tip can brake, letting loose a buch of needle bearings and metal shavings into the engine. This HAS happened before, MANY times, and not just to me. Quality is important for roller rockers.

Increasing the ratio DOES give power gains. It opens the valves more (lift), but for the same period of time (duration). This causes the valves to open and close at a faster speed because they need to achieve a larger opening in the same amount of time. Can you say "added stress"? Your worn factory springs are now trying to handle the extra lift and lifter speeds that it was never designed to handle. This causes valve float, and sometimes piston to valve contact!

When we install the roller rockers, we make sure that we have stronger valve springs, as well as proper valvetrain geometry and piston-to-valve clearance.

5.0 HO Ford motors can handle these increased ratio roller rockers simply because the HO motors were overbuilt. They have stronger valve springs (as well as other parts) than necessary, making it a perfect upgrade.

I suppose you could run a large ratio roller tip rocker in a OHV 4.0 for awhile. But I wouldn't expect it to last as long as the stock engine would. This upgrade would be ideal if you had the heads off or engine out and were rebuilding everything. This would allow you to upgrade the springs, as well as adjust them properly for valvetrain geometry.

Another thing that some people believe - if you want to upgrade to large ratio rockers, it's better to install a larger cam instead. The larger cam is designed to open and close the valves at a better speed than the stock cam with a large ratio. This will prevent valve float and give you the same performance increase. Personally, i think this is true to a point. The point is that the stock cam is so mild that the increased speeds are insignifigant as long as the valve spring tension is increased to prevent valve float.

Overall, i WOULD like to see someone produce some quality roller rockers for our engines. Because now that many of us are beginning our rebuilds, we will have an option for more power rather than purchasing a cam.

 

[SteveVB]

I dont have all of the answers yet.

Power gains would depend on the ratio that is run. A 1.6 ratio would add about 10% to the lift figures on a cam so a guess of a 5% gain -8-10 hp maybe more. But until they are installed and tested who knows.

Should be a bolt on with removing the originals and replacing, Im checking on this, new push rods maybe but I doubt it unless you have changed the camshaft.
That brings up a good point - putting higher ratio rockers on to increase the lift may7 be cheaper than changing the cam- in the 4.0 you need to remove the engine to change the cam-in most cases. The cost for parts would be less than a cam change also- Thats something else to think about, could work out to a cheaper alternative than changing the cam, which is really only feasable during a rebuild.

 

[SteveVB]

BRacing, we posted at about the same time, heres some things I didnt address in my last post that you brought up.

First the stock rockers are made from cast iron. The wear in the pushrod cup and the valve tip contact area is considerable in higher mileage engines. I believe the roller tip and a hardened cup will drastically reduce (or eliminate) these problems. When I rebuilt my engine the rockers/pushrods were in really bad shape.

These rockers are shaft mounted so lifter preload and geometry are controlled by the pushrods, and unless the ratio changes the length they should be fairly painless to put in.

Im in contact with Harland Sharpe about the rockers. I think the only way anyone will see rockers for the 4.0 is to have them custom made. They wont do a run unless they can get 20 or so orders , so if anyone is interested they would need to have them made.

So anyone else interested.

 

[Alec]

I thought the 4.0 OHV rockers were the same as the 5.0. I think that was stated about 6 months ago on this board. Therefore, couldn't you get the 5.0 set and only use 6 of them?

 

[SteveVB]

Alec,
I didnt see that- but from my memory that doesnt sound right. the 4.0 has cast iron rockers on a fairly small dia shaft, I have never seen the 5.0 rockers are they even shaft mounted? pedestal?Stud? I thought stud - its been years since ive seen a 289 or 302, and I never had my 90 stang opened up for anything other than maint.

 

[Doug904]

PLease veiw my responce on the this topic on this board..

Dead Link Removed

 

[SteveVB]

problem solved.

no need to get 20 orders now I guess.

Do you make them or do you have them made? Do you use the stock shafts or are the shafts and spacers included? They accept the stock pushrod end?

 

[SteveVB]

Question Doug.

Doug what size valves are you running in what year head?

 

[Doug904]

I have them made by "Probe Industries" a very well known manufactorer of high performance race products. There is another company that sells these same rockers but they sell them at a higher price then I do. Im not in it for the money I just love the 4.0 performance idea and the look on a unsuspecting 5.0 owner when I fly by him.

1) Yes they can be used with your stock rocker shafts. They acuatally come seperate and have to be assembled on your shafts. For a small extra I will assemble them on hte shafts for you and all I ask in return is that you send me your stock shafts so that I can have them for the next set. IF you liek I will return your stock rockers.

2) Yes they accept stock pushrod ends. These were designed to be a direct bolt on. There isn't any modifaction nessesary to install them on your 4.0.

3) I run the stock size vavle in my cylinder heads. The heads aren't really large enough to run an oversize vavle and it just isn't practical to do this. WHat I do run are the 98TM casting cylinder heads due to there better intake runner and round exhaust runner which equals to better flow numbers. You need to port the exhaust, really just kinda clean and smooth it, but it will yeild greatly increased flow numbers over the stock D-shaped exhaust. Something to remember if you wanna run 95 or newer heads on a pre-95. The combustion chamber is 10cc smaller so this will increase your compression ratio to 10:1 rather then 9:1 giving more performance but if your running a supercharger or nitrous this isn't always what your looking for.

Here's something else you guys might wanna check out with the weak tranny. I wrote a C4 installation guide for the 4.0. I don't know about the 4x4 but I can tell you in my 2wd for the drag strip its great!

C4 transmission installation guide