2056 L - Jet Build advise request Options

[eyesright]

No hijack intended, but what happened to the Raby 9550 cam? and what is the difference between it and the 9590?

someone will know for sure, but I believe I heard that soon after I bought my 9550 it was improved and given a new number. Can't remember the number but maybe it is the 9590. Sorry no details and no confidence in the answer, but I bet I am somewhat right> only bet a nickel on it tho.

I bet I got the last one! I ordered a 9550 kit on a Friday. The following Monday they announced that 9550 was discontinued and replaced with 9590. So on my next build I guess I'll go with the 9590. They say timing is everything and my life is full of stories of being a day late or in this case a day early. I'd be disappointed except that my engine runs so sweet and gets 33-35mpg. So thanks Jake for the engineering, and Len for the head and case work and a little advice, and LN for taking on the store.

And in another sense, I guess timing IS everything! A good engineer's motto.

[Jake Raby]

No hijack intended, but what happened to the Raby 9550 cam? and what is the difference between it and the 9590?

someone will know for sure, but I believe I heard that soon after I bought my 9550 it was improved and given a new number. Can't remember the number but maybe it is the 9590. Sorry no details and no confidence in the answer, but I bet I am somewhat right> only bet a nickel on it tho.

I bet I got the last one! I ordered a 9550 kit on a Friday. The following Monday they announced that 9550 was discontinued and replaced with 9590. So on my next build I guess I'll go with the 9590. They say timing is everything and my life is full of stories of being a day late or in this case a day early. I'd be disappointed except that my engine runs so sweet and gets 33-35mpg. So thanks Jake for the engineering, and Len for the head and case work and a little advice, and LN for taking on the store.

And in another sense, I guess timing IS everything! A good engineer's motto.

THANKS!! You probably did get the last one. I kept one for the museum, though :-)

[HAM Inc]

What is the difference is head flow between the stock heads and the RS heads?

Curious how much change is occurring....

On a 2056, about 15HP worth of difference back to back.

On the flow bench the peak flow is very similar, but where the flow peaks at is different and low lift flow and chamber filling is dramatically increased.

The biggest difference is the altered port flow margins between intake and exhaust ports. Remember, peak flow mans a lot less than where the flow is made and what intake : exhaust flow margins are.

These port flow margins work really well with the split duration cams that I developed as part of many engine combinations.

Here's a graph that was handy from the 2006 offerings, the RS is more refined now than this, but this is the general idea. Remember, this is dry flow data and doesn't show swirl, or tumble, or port velocity. But we have all that data as well.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.aircooledtechnology.com-1095-1415941456.1.jpg)

That's flow data from two generations ago. We blew past that a while ago. We no longer put flow data out for public consumption, but let's just say that the current version of the RS+ is substantially more potent. That data was from the transition version when the RS+ superseded the LE-180.
Here's a link to our facebook page with pics of the latest RS+
https://www.facebook.com/HoffmanAutomotiveMachine?ref=br_rs
Our latest heads with the upgraded cam offerings will make for an even stouter power-plant than even just a few years ago.

(IMG:style_emoticons/default/beerchug.gif)

[Olympic 914]

Cool. one of the other poster said he built an engine with those heads running my favorite....Djet.

Just curious if I could try something new....different and push it a bit more...

Will wait to see how it runs in his car to see if it's worth pursuing the heads...but I might just to see if it can get a little bit more from djet.

Will be awhile till it runs. the engine is done







But the body work is progressing slowly.

[Olympic 914]

Damn, don't know why the picture did that..???


Fixed....