thesoundandthefury

I was reading a thread on www.smokemup.com recently, and a gentleman on there made this statement:

http://www.smokemup.com/bb/viewtopic...er=asc&start=0

From what I've heard, it's possible to run big block Chevy rockers on small block heads, but I'm not 100% sure if they're a straight bolt on and go install or if there are modifications necessary. But logic seems to dictate that if a set of big block Chevy rockers would work on small block heads, and Ford rockers will work on big block Chevy heads, then there's a possibility that Ford rockers will also fit small chevy heads too?

Has anybody ever seen, heard, or done this before? Does anything have to be modified for them to work?

TIA

seawolf06

Don't BBC heads look like the twisted wedge heads that have different intake and exhaust angles? I can't imagine they would work, but they might. Someone does make a 1.65 rocker for SBC, I just can't remember who.

mdacton

if you got money you can do whatever you want......I had BBC 1.7's on a 2.8L 60* v-6

thesoundandthefury

Reply from a guy in the thread I made there:

http://www.smokemup.com/bb/viewtopic.php?t=3085
I'll post more info as I receive it.

z282slo

all my buddy's with fords and stud mount rockers use sbc rockers

thesoundandthefury

Nice to know if someone were to come across a good deal on a set of big block or Ford rockers.

red67camaro

I would check fit and geometry very carefully before swapping rockers from another engine platform.

I can't say as far as fitting Ford rockers on a Chevy engine, but this thread rang a bell for me on running BBC rockers on an SBC.

I just checked in an old Smokey Yunick book I have and he mentioned running BBC rockers on an SBC. He said that due to the rockers being longer, the stud had to be moved away from the valve ~.150" in order for the rocker tip to properly index on the valve stem which also moved the pushrod toward the intake side of the head causing clearance problems there too.

Not that it can't be done, but it seems like a lot of work when aftermarket rockers with different ratios can easily be had that do in fact bolt on.

thesoundandthefury

Thanks for the heads up. I'll see if I can get the guy who made the "they bolted right up" comment to elaborate on if he had to do anything specific to make them work.

buzz12586

It probably made sense to do 20-30 years ago when the aftermarket wasn't as big but now you would be better off getting whatever ratio you wanted designed for your car.

JAKEJR

From all I've read about running BB rockers on a SB head, the SB rocker studs have to be re-located to make them work. There use to be a company that made "off-set" studs, sort of like offset rocker arms offered by Jesel and others which could make them a bolt on.

Of course, pushrod length and other geometry issues would have to be checked. Since high ratio SB arms are now so readily available I figure "why bother". Yesterday I received a set of SCORPION 1.7; 7/16th stud RRs for the 388 I'm building. Impressive looking pieces, too.

As far as the Ford rockers on a BB Chevy, I believe they were off Cleveland heads or maybe BOSS 302 rockers which replaced the stock "ball and sled" rockers on the 468 BB I was running. This was MANY years ago, but they had a 1.75 ratio and had removable needle bearing inserts (whatdoya call it, the trunnion?) that went into the arm body then down onto the stud.

I suspect they'd be pretty hard to find now, but they were a direct bolt on.

Jake

JAKEJR

Yep, at LEAST 30 years ago.

Jake

thesoundandthefury

Jake,

Excellent info, thanks. I guess I should clarify: the reason for asking questions like this is to learn the historical significance of things.

Take the tri-power intake setups that Ford and GM made back in the 50's and 60's for example. It was a cool concept that had the ability to make some awesome power, but both companies stopped making them after a relatively short run. And the aftermarket has all but abandoned the idea. Why? I guess it might have something to do with the fact that unless you had the patience of Job, and a somewhat better than average knowledge of fluid mechanics, getting one tuned and keeping it tuned was an exercise in futility. In other words, just a tad bit too complex for the likes of your average John Q. Shadetree.

But then flash forward 30 or so years to the 80's and the dawn of the age of computer controlled engines. The late 80's brought us the LT5 engine which had a unique tuning characteristic called "displacement on demand." Once again, an extremely cool concept that offers the best of both worlds: great fuel economy and emissions, and brute horsepower. Back in the 50's and 60's, nobody gave a rat's behind about fuel economy and emissions, so at that time the tri-power concept was driven simply for the sake of making more power. But one has to wonder: when comparing the tri-power intake to displacement on demand, and seeing that both concepts perform in an almost identical manner, did GM maybe learn some things in the process of developing the tri-power that didn't have anything to do with the original target goal? I think so. Could it maybe be said that we now have one thanks to the other? I think so too.

So bearing this in mind, when I ask about the why's and wherefore's of Ford rockers on Chevy heads, it's not because I think that this is some revolutionary way of making more power, (but heck, who knows, anything's possible), but because there's a chance that there might be a beneficial silver lining in there somewhere that doesn't have anything to do with higher and different ratios.

Knowhutamean Vern?

JAKEJR

I recall, some time back on another Forum, the guys were kicking around whether it's better to have the valve lift ground into the camshaft lobes or get it with a higher ratio rocker arm setup.

Of course, like most things, there were differing view on this and there seemed to be no consensus.

A while later I came across an article written by one of the Big Boys in the camshaft industry - I believe it was CompCams or Crane - that came out in favor of going the rocker route, saying that's the way to do it.

I guess GM read it too since their HOT LSx engines are all sporting high ratio stuff these days. LOL In fact, that's what convinced me to go with 1.7s; trying not to leave too much on the table.

Wish I had made a note of where, exactly, I read it but something keeps telling me it was on-line, on one of their sites.

I'll try to do better next time.

Jake

SS Joe

Crower makes 1.65 roller rockers for the SBC. Back about 15 years ago when I was building a 377 for my Nova, Super Shops (remember them?) was out of 1.6 Erson 3/8 stud roller rockers for SBC, and sold me some that were labeled for Ford. The part number was different, but they said they were the same part, and they worked fine. Looked identical to some display 1.6 Chevy rockers thye had in the store.

crazydavez28

doesn't changing the ratio of the rockers increase the duration a little bit?

i mean duration measured at .050" with 1.6/1.7's would actually be greater than that of 1.5's