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roller rockers

Those Yella Terra roller rockers are the only ones that bolt straight onto the 4.0 (or stroker) without any machining of the head required for larger studs, so they have a good advantage over the Mopar Performance and other RR's.
If they didn't cost as much as $440, I'd go for them but I think they're still too expensive (MP's cost $680) for the sake of gaining ~5hp. I'll probably gain that much with the $50 crank scraper.
 
I always thought the MOPAR and Hessco RRs were bolt on. They do need a Valve cover spacer though. Does the QT RRs not need a spacer? I think Mopar and Hesco are adjustable. The set I have at home are adjustable, but I got them off of E-Bay and not sure of the manufacture. They look like Hessco's without the anodizing.
Tom
 
The Mopar Performance and Hesco RR's are the same thing, are adjustable, and need a valve cover spacer for clearance. Hesco sell the RR's for $645 and the spacer for $80, so that's a cool $725 in total.
The Australian Yella Terra YT6627 RR's are non-adjustable and fit under the stock valve cover. They also have adjustable versions (YT6328) that need a valve cover spacer for clearance.
 
If they didn't cost as much as $440, I'd go for them but I think they're still too expensive (MP's cost $680) for the sake of gaining ~5hp. I'll probably gain that much with the $50 crank scraper.

That says nothing about the ease of installation. I doubt changing the rocker arms would take more than two hours, working deliberately rather than quickly. Roller rockers make an instant and marked improvement in the engine's smoothness at all engine speeds; the crank scraper makes a slight but noticeable difference in smoothness only near redline.
 
Are the YT on a single shaft? If so then comapring them to other brands on a single shaft, they are cheap. Still, the single shaft probably doesn't give you any more power. Still, it hurts to see Chevy and Ford RRs go for around $200 a set.
Tom
 
FSJ Ralph said:
That says nothing about the ease of installation. I doubt changing the rocker arms would take more than two hours, working deliberately rather than quickly. Roller rockers make an instant and marked improvement in the engine's smoothness at all engine speeds.

That's absolutely correct and I wouldn't hesitate in buying a set of RR's if they cost closer to $200 rather than $440.
I think it all comes down to the economies of scale. Far more Chevy and Ford RR's are sold than Jeep RR's so they can be sold cheaply and still be profitable to the manufacturers.
If several of us jumped on the bandwagon at the same time and put together a group buy for the YT6627's, maybe Quadratec would give us a substantial discount on the price.
 
hmm...I guess it all depends on where ya look...

I just scored a brand new set of Mopar 1.6 RR's for $260

yeah...I know I gotta buy the spacer...no biggee

for all the money sunk into the stroker project, I think RR's give me more peace of mind than performance... My understanding is that they may extend the life of your valvetrain by reducing friction and stresses

yeah... they really shine shine in upper rpm situations, but when my 4.7 Renix is rev limited to 5200(?) it's a mute point

I think the mopar RR's will complement the Eaton M90 :D
 
Harland Sharp also makes a set that will fit under the stock valve cover. The rockers are $300. It requires a special set of rocker studs that are 5/16 on the bottom and 3/8 on the top and have no hex for tightening. The pictures on HS's web site are not working so I am going to call them when I get a chance. They also mention something about some machining needed so all in all the $440 for the QT price doesn't sound that bad. The HS's are another option though.

Personally I like the idea of RR of any sort over the stock type, just from a reliability stand point. $400+ is a bit steep but in the long run it may be worth it.

B-loose
 
Bloose said:
Harland Sharp also makes a set that will fit under the stock valve cover. The rockers are $300. It requires a special set of rocker studs that are 5/16 on the bottom and 3/8 on the top and have no hex for tightening. The pictures on HS's web site are not working so I am going to call them when I get a chance. They also mention something about some machining needed...

Yeah, the rocker stud bosses need to be shortened by 0.4" and the threads retapped so that the HS rockers will fit under the stock valve cover. I'm not too enthusiastic about that idea.
 
Mine cost under $200 off of E-Bay. Go figure. I got springs and push rods. I am using the springs in my Big Chevy SS valve conversion. Might have pics of that soon. Still, those deals don't show up evry day. I think the HS, you have to cut out the oil shielding towers. Crower is another option at $300, but you might need a spacer.
Tom
 
I've looked into other options where 5/16" rocker studs can be used and came up with the following:

Proform 66879 SB Ford Extruded Aluminum, Roller-Tip, 1.6 Ratio 5/16”
Fits Ford Aluminum SB Pedestal Mt. 1.6 Ratio 5/16” stud. 1977-1994, 302HO & 351W Hyd. & Roller Cams

CompCams 1052-16 Ford 302-351W 1977-92 5/16" 1.6 Ratio

Steeda 1.6 Ratio 5/16" Bolt Down Rocker Arms $234.95 for the same engine

Does anyone know if these might work? I already have a Mustang 65mm TB and Mustang 24lb injectors on my stroker so why not add more Mustang parts? They'll cost half the price of the Yella Terra RR's so that'll be a huge cost saving.
 
Regarding the Harland Sharps...

Their RR's are about $218 (I spoke to them about 2-3 weeks ago), they had one set on the shelf

I priced out almost everything listed in the write-up below and it came out to around $400, not bad considering you don't need the spacer, machining is minimal, and that included the valve springs, retainers, etc.

I did not price the Manley valves though...

Check it out

roller rocker write-up
 
Gil BullyKatz said:
Regarding the Harland Sharps...

I priced out almost everything listed in the write-up below and it came out to around $400, not bad considering you don't need the spacer, machining is minimal, and that included the valve springs, retainers, etc.

roller rocker write-up

According to the write-up:
The following machining operations are required to install the rocker arms:
Mill stud bosses 0.400"
Drill and tap stud holes deeper (to match studs) and chamfer

That's a little bit more than minimal machining and it can only be done properly if the head is removed. Not exactly a bolt-on job, and that also adds to the cost.

Internal valvecover PCV baffles must be removed

Won't that compromise the function of the PCV system?
By the time you've bought the HS rockers, added all the other bits, and done the machine work, the cost will exceed the $440 price of the Yella Terra YT6627's which bolt straight on under the stock valve cover without any modifications needed.
I'm gonna find out if the Mustang 5.0 RR's will be compatible for the Jeep 4.0/stroker. They also use 5/16" bolts so the head won't need to be machined, and they come as pedestal mount which makes it easy. The only issues are the length of the rockers and whether they'll fit under the stock valve cover. The Proform RR's cost just $169 so if they do work, it'll be a hell of a cost saving.
 
Sephrion said:
anyone get a chance to check out quadratech's "hi performance" roller rockers yet? was wondering if they'd be worth adding to a 4.6L stroker build.

Dr. Dyno said:
According to the write-up:


That's a little bit more than minimal machining and it can only be done properly if the head is removed. Not exactly a bolt-on job, and that also adds to the cost.

Just giving the guy some options.... Sometimes "Bolt-on" doesn't mean "right-on"
And how many people are actually running them (YT's)? There's a couple of guys on the KC Jeep board that have been running the HS's...
and If you're doing a stroker build the pcv baffles are your least concern, I've been running without baffles and just a breather up front and the return line out back.
Good thing about a machine shop is they can scope out ALL your tolerances...

It's what they get paid for...
 
Dino,
The RR's I have use a post to place them above the rocker boss. I think the Ford pedistal RRs use a 'T' post. No real difference though, except I think the square bootm on the Fords help locate them, since they are in single form and the Hesco and Mopar are two on a shaft. If I can find time, I might be able to take off my Valve covers of the 351W and compare. They aren't pedistal RRs though. I can try and figure out how far the Jeep ones are above the bosses. Still, you will need to shim them up or down to maintain geometry. Also, I've seen AMC RRs with pedistal mounts. Don't know if they'd be a better choice or not.
Tom
 
Maybe I'm stating the obvious here, but it seems these companies price their respective sets of roller rockers according to the labor and expense of installing them, and not necessarily to compete solely on price of the rockers themselves.

For example, Summit Racing lists the Harland Sharp rockers for $285.39, yet it's about a grand to do the complete run of mods listed on Harland Sharp's website. Just to remove the head and have it machined so that the HS rockers will fit involves a considerable amount of time. While the head's off, one might as well go whole hog and do other mods besides just having the stud bosses shaved 0.4".

I can see that the Hesco/Mopar rockers have a few more internal parts, so a slight bump in price over the HS rockers would be in order. Hesco lists their set for $645, plus a required valve cover spacer for $79.95 -- I assume this requires two valve cover gaskets? -- plus a thermostat housing for $27.95, plus shipping. Worth the price of admission?

The latest Quadratec catalog lists their Yella-Terra Rockers for $439.95 plus shipping. The description states that they "...can be fitted in around 1 hour with no head removal, machining or valve spacers required." This sounds like the best bang for the buck, insofar as roller rockers are concerned.

Can anyone chime in with their direct experience with the Yella-Terra rockers?
 
I went to the Jeep and Ford dealers today and got hold of OEM rocker arms for both the Jeep 4.0 and the Mustang 5.0 so I was able to compare them. Unfortunately while the two do look similar, the Mustang rocker is shorter so it ain't gonna work. That's a shame because the pedestal mount RR's would have been easy to install with 5/16" bolts. :(
I don't know if the AMC 304 V8 RR's will work but the only ones that I've found use studs that are at least 3/8" and some use 7/16". Either way, it ain't a simple bolt-on job.
It looks like the only simple bolt-on RR's are indeed the Yella Terra YT6627's. As I suggested in a previous post, we could get a discount on the $440 asking price from Quadratec if we put together a group buy. Anyone interested?
 
What is the procedure to modify and fit BBC 1.7:1 roller rockers?

Can studs be machined to make these work, and gain a lift/duration advantage as well as the RR reliability?
 
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