Roller Rockers?? Hey engine pro's, got one for ya!

[ibnfe]

Alright, I'm perplexed. All the tech folks I've talked to say that there is no head tower shaving required to put roller rockers on my heads. So out to the parts store I go. I pick up the Miloden 3/8 studs (same as SBC), Isky adjustable guideplates, new pushrods, and Comp Cams Magnum Roller Rockers(also same as SBC according to PN). As I go to assemble everything, my new (and old) pushrods aren't even close to long enough, atleast 1/4" short if not a bit more. The rockers bottom out on the studs before touching the pr's. So what's the catch? If I use longer pushrods, anybody have the exact length or part number? Or do I have to shave the towers down? Of course it's too late to call those tech guys up and ask I checked over at froadin.com but he used the Harland Sharp rockers.

[jeepbob]

Did you get 1.5 or 1.6 ratio SCB rockers? You need 1.6 ratio. The Harlan Sharps may cost a little more but they are made for AMC motors and only cost $3 total more than a chevy set. Also HS has been building roller rockers since the early 60's.

[ibnfe]

They are 1.6 ratio. The part number was listed for the AMC V-8, just so happens the same part number is listed for SBC. These roller rockers I have are fairly deep like the original stock rockers. I have a set of the Harland Sharps on the way, hoping that they aren't so deep from the base of the pivot to the contact surfaces. I hate swapping stuff through the mail... Pay first, get reimbursed, pay the shipping back, big losing game there The other thing working against me is the Miloden studs. They're good, don't get me wrong, but they have alot of "extra" shoulder that is working against me as well.

[WillyPete]

what are the benefits of swapping in rollers? AMC 360s come with hyrdraulic tappet, right?

[Stuka]

Rollors allow for less friction, and allow for more rpm's if you have a full rollor system (rollor cam, lifters, rockers)

Generally if you can get rollor stuff for any engine its worth it.

[SpruceMoose]

but how much friction will you lose at a cruising rpm of, say 2200 rpm? thats what mine runs at, and hardly ever sees more than 3500 before a shift. doesnt seem worth it, unless you need to change 'em out anyway, and/or you just like shiny goodies under the valve covers.

[Stuka]

right, at cruising rpm there is a huge differance with just rockers, If any differance at all. If you had rollor everything, then it would make a differance. Rollor cam, lifters, rockers, oh, and timing chain. A Double rollor timing chain is stronger and less resitance. Just, is it worth the cost for what you gain??

[ July 12, 2001: Message edited by: Stuka ]

[ibnfe]

I just can't see putting alot of $$$ into building a brand new motor, then stacking the "prone to crack" stock rocker setup in there. I don't like the 5/16" bolts that hold 'em, nor do I like the non-adjustability of the stock setup. In my eyes, something that has a bearing vice a friction wearing surface is going to work better and last longer. Granted I may not see any performance increase, but in 100,000 miles I don't need to question the reliability of the valve train. This is far from the only "straying from stock" I have done so far, it just seems to be the biggest pain in the backside.

[YJason]

I remember reading about the roller rockers on the Comp Cam page. You have to get custom made, longer rods. I think that they have a part # at the tech dept., but you have to call to get it.

[jeepbob]

Roller rockers by them selves are good for up to 25 hp but at the speeds that our motors are running it would be a realistic 5 to 10 hp and the HS are only $50 more than putting in stock parts but this does not include putting in the studs or the studs, guide plates, or hardened push rods. Depending on your skills, add another $50 to $100. If your motor is seeing higher rpm like mine does then it is worth the money. If I ever get my new block back then we will see just how much better. The new motor seem tons stronger right up till the block cracked with 345 miles on it.

[ibnfe]

stock length Hardened PR's $44, Isky guideplates $41, Miloden studs (if your heads don't have em)$33, HS roller rockers $200. The rockers will be here Monday, I'll leave a post and let you know if they fit properly or not. YJason, thanks for the tech page tip, didn't think to check their website. Jeepbob, what happened to crack your block?

[JEEPRZ]

What valve covers, or spacers do you need with these rockers?

[ibnfe]

Alright, the verdict is in on the roller rockers. The Harland Sharps came in and they would not work without longer pushrods. But I am still happy I got 'em. They are much better quality than the others I had. If anybody intends to do this, you will need 8.280 long pushrods. Now, if you want to aleviate this need, have the stud towers machined down .350" and the stock length will work fine. I just couldn't justify pulling the heads back off and disassembling to do this, especially since this setup didn't throw off the rocker to valve geometry. Also, this only applies if you have the bolt in bridge and rocker setup and have to drill and tap the bolt holes for studs. If you have the early 70's heads that have studs already, they had the stud towers machined at the factory.

[jeepbob]

The block cracked with a .030 over bore due to a shifted core when it was cast. The block was scrap when it was new