914-6 Conversion Shift Linkage Question, Straight or Bent? Let the opinions fly Options

[John]

I am about to fabricate some rear shift linkages for some -6 conversions, and have been seeing a slight bend in the rear shift rod.

When I did the conversion 13+ years ago, it was common(?) for the shift rod to be absolutely straight as is confirmed by my existing shift rod. We purchased the straight rod from a vendor in CA 13 or 14 years ago possibly from Galen Bieker and it has worked well for both the original 901 side-shifter as well as the current 915 (vellios) transmission.

My main questions are:

1. Is there a need for the shift rod to have a slight bend?
2. Does the slight bend help minimize binding in the bushings?
3. Is the bend to avoid bumping into the bottom of the engine case?
4. What is the location of the slight bend(s)?
5. Is there 2 slight bends or is there just one?

Pics would be very helpful.

Otherwise, I'll continue to make up straight ones and verify that they work with my existing 914-6 conversion.

Thanks for your input.

[john rogers]

When I did my conversion I had to put a slight bend in the rear rod section. This was to clear the case. I used one of the aircraft type couplers so there was less free play at the front and stock type bushing at the rear.

[Trekkor]

Back when I did mine, the first thing I noticed is that the stock shift rod for the FOUR is *very* bent. I works fine very bent.

I just cut mine at both ends and rotated the bend downward to clear the headers. Something like 60 degrees IIRC.

The shifting action feels exactly the same.

here's a couple of pics:


KT

[Mueller]

I thought it was the motor mount that also had a bearing on whether straight or bent???

[Trekkor]

The motor mount is directly above the shift linkage tunnel exit. No interferance.

People have said the bend looks outrageous, it's the same ol' bend. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

Another pic:


KT

[Mueller]

QUOTE (trekkor @ Feb 13 2006, 11:12 AM)

The motor mount is directly above the shift linkage tunnel exit. No interferance. People have said the bend looks outrageous, it's the same ol' bend. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) Another pic: KT

what about the "quick-six" mounts??

[Trekkor]

If you are referring to the Patrick mount, that's what I use.
I believe the "Quick Six" is offered by Motor Miester and I haven't seen that one.


KT

[John]

KT,

Which headers are you using?

[Trekkor]

MSDS headers.

Martin Schneider, MSDS, inc

http://www.msdsinc.com

I really like them and they sound great. (IMG:http://www.914world.com/bbs2/html/emoticons/wub.gif)

KT

[brant]

Trekkor,

taking the bend out as much as possible, is theoretically better because there is less chance for the rod to flex.

Theoretically you could also make a lighter rod (lighter material) because it would not have to be as strong of material in order to be flex free since straight is a stronger shape than bent.

that may all be just theory and not matter in real life.
but we made ours straight with very light weight (thin-walled) stock to try and take advantage of this.

Regarding the original question.
tiny... barely perceptable bend in the final 6 inches of the rod. Helps free up travel through the bushing in the side shifter console.

brant

[Trekkor]

Nearly all 914's use a shift rod this bent.
I don't think they flex.

Sorry, I should have just let it go... (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)


KT

[brant]

The original -6 rod is not bent... and some say its better.

Its only theory...
pretty much impossible to prove
I did it because our race shop said that it was less flexible on the BIG time track cars they build.

I reality its impossible to prove, but every little thing helps.

brant

[736conver]

No scientific data here, but I made my shift rod straight for my 3.2 conversion.

[John]

So I have a couple for straight (me and 736conver) and I have a couple for slight (or more) bent.

The one that PMS pushes (and we didn't use and he wouldn't take back) has a slight bend about 6" from the front (firewall) end. James uses a steering shaft universal joint at the firewall (which we again did not use as there was no provision to install the dust boot). I think that the slight bend is to simply clear the engine case.

I do recall that I did some slight grinding on the bottom of our case when I installed my straight shift rod many years ago. Perhaps if the engine and trans were not bolted solidly into the chassis, I would need a bend as the engine would move around.....

I think I'm going to make mine straight. I could always put a slight bend in it if needed.

[RON S.]

John,


I made mine straight,it seemed the simplest way to keep it simple.


The tube is 4140 I got from Mcmaster,and i Apex coupling up front.It seems to work just fine.

Heres 3 pics to show.

Ron

[RON S.]

#2



center section

[RON S.]

Last one,


Tail section,

Ron

[IronHillRestorations]

I've been making conversion shift rods for the last eight years on a jig I built specifically for the part. I say if you are building these for sale..... go ahead and make them straight ....... (IMG:http://www.914world.com/bbs2/html/emoticons/happy11.gif)

Seriously, if you measure the shift rod connection points, from the centerline of the car, you'll get your answer.

[Dr Evil]

I had mine bent by Dan Root because it was recommended. Shifts fine (for a car of jack stands) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[John]

I started out and made a jig from an original shift rod and tried several (about 5) other original shift rods. Each of the shift rods were slightly different. Only 2 fit nicely in the jig.

There is some offset between the ends of a stock 4-cyl side shift bar (which is why I asked the question in the first place).

I ended up taking my known to work (for the last 13-14 years) shift rod (straight) out of the converted car and made a jig from it instead.


I may try some slight bends to see if they make any difference since nobody seems to know a definitive answer.