What Roller Rockers are these?

[DPDISXR4Ti]

I recently picked of a 4.0 and as I'm about to drive away the guy mentions, "I think that may have roller rockers in it." Got home, power-washed the engine, and like a kid waiting for Santa to come down the chimney I removed one of the covers. Score! I don't see any identifying marks on these and they look a little different from the ones I see listed for sale. Anyone recognize them? I'm wondering if they are stock ratio or increased.

 

[Dirtman]

They don't look like Morana's?

 

[DPDISXR4Ti]

They don't look like Morana's?

Nope!
http://www.moranav6racing.com/img/Products/pictures/IMG_2243.JPG

 

[snoranger]

I know that a guy named Doug904 from Explorerforums was selling custom roller rockers for the 4.0l about 20 years ago. He had them made by Probe industries.
These may be them.

 

[fastpakr]

Was he the one that ran Bama Tuning (or a similar name)?

 

[snoranger]

Was he the one that ran Bama Tuning (or a similar name)?

I think so.

 

[fastpakr]

Bama Performance - Home

www.bamaperformance.com

That's him. Maybe he'd answer the question?

 

[DPDISXR4Ti]

Thanks for the lead - it led me to find these old posts from Doug on the Explorerforum. What makes me certain these are the Probe Industries rockers is that the heads on this engine are 98TM castings as recommended by Doug. Perhaps he built the heads and sold them as a turn-key plug-n-play? I've tried to contact Doug via the two e-mails I found for him, but both bounced.

September 20, 2001
Hello, I run a set of 4.0 roller tip rockers. They are 1.6 ratio, stock ratio is a 1.46, and they are made of Billet aluminum. They also come with a lifetime warrenty against defects in workmanship and material. They have a Roller tip and a broze bushing. They work with the stock rocker shaft. Now for the best thing of all, they are also ADJUSTABLE!!! So there's no guessing game when it comes to pushrod length for that new cam. They will work fine with your stock cam or performance cam. The Rocker's reduced my engine temperture by 10 degrees under normal driving conditions and improved throttle responce greatly. They increase lift by .030 and give your cam 40 degree's more duration. They are very nice peice but they do come at a price $374.99. I'll try to post a picture of them or a link to one. Im not too sure how this forum works with pictures!! If your interested then please email me.. Dstuddard904@aol.com Thanks Doug904.

P.S. I also can offer you a dual spring with retainers set up if your worried about this but its not nessecary to run with these rockers. I do recommend them with a larger cam. I do alot of aftermarket performance mods to the OHV 4.0 and I have alot of information for the not so faint of heart dealing with internal mods and cylinder heads. You can get alot of power from the 4.0 but it comes with a price, its not as bad as you think but its up there. Im currently building a web site that will detail alot of my experiences with my 4.0 and some others I've delt with. So far the best tuning I've done to a friends 4.0 Splash ended up with a 12.90 1/4 mile time. I'm working on my new enigne this year and hope to do alot better!! i've done everything from dual springs to polishing the rods. Blueprinting and balancing everything!! So feel free to ask any questions you like and to just drop me an email with your mods, I love to talk 4.0's and like to meet new peolpe!!
----------------------------------------------------
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.

 

[Dirtman]

So what you're saying is, engines is goes vroom?

 

[snoranger]

So what you're saying is, engines is goes vroom?

With roller rockers... engine is goes vroom faster.

 

[dvdswan]

So you could say that it goes... Vroom Vroom. Just a guess since Mazda goes, Zoom Zoom. And Vroom Vroom is so much better.

 

[DPDISXR4Ti]

I spoke to Doug last night and he confirmed that these are the Probe Industries rollers, likely sold by him. He only sold about 8 sets back in the day and wanted to buy them back! He made about 280HP using these with a 125 shot. He indicated that he probably did not build this particular engine as he usually used an after-market head that didn't have the 98TM... part# in the casting.

I asked him about running this setup on a stock '94 calibration and he said I'd probably be okay as the factory tune was really pretty conservative with a fair amount of margin. This from a guy that made his living for a lot of years as a tuner. Worse case maybe I'd need to slot the mounting holes for the crank pick-up so that I could set base timing at 7 or 8 degrees instead of 10.

 

[Doug904]

And those are 24lbs injectors so you'll need the right MAF for that. Stock are 19's

 

[Doug904]

What PCM are you using? I may can burn a chip for you. Give me the 4 digit code on the label from it.

 

[DPDISXR4Ti]

And those are 24lbs injectors so you'll need the right MAF for that. Stock are 19's

Indeed they are 24's. The guy I got the engine from claimed he ran it on a stock ('94 Ranger) PCM. If true, I wonder if it even went into closed-loop. I was thinking if I first wanted to try running it on a stock PCM/MAF I might throw some 21's in there. That might help with what I think will be a tendency to knock (due to 10:1 CR), but still go into closed loop since only 10% over stock fueling.