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Help needed firguring out steering geometry


Seedy Al

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Ok, so I have an issue with my Crown setup in my wag. So I am currently converting it to steering rack, using a VN commy one, to get some clearence with mounting my 3v etc.

However I have an issue, Where i want the steering rack to come up to meet the column, there is a starter motor. and I am having alot of issues coming up with a way to re-route the starter etc. So My Question

Am i able to locate the rack slighty to one side (as opposed to center of the vehicle like in a holden), without having major lock issues etc. One thing to note, is that I need to make adapters to match the crown tie rod ends to the Holden rack ends. So If i centered the steering in the rack it self, and then made the left hand side adapter longer than the right hand side, to make the wheels straight, will i still have the same lock on both sides

And if so, is it going to effect bump steer or anything like that (bump steer is not an issue I am that worried about, its a wagon, not a race car)

So yeah, help, thoughts and descussion reqiured.

thanks in advance. Will make a picture to clarfy things

Seedy Al

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I would be thinking it could give you different bump steer from left to right. which could be no big deal, or could be dangerous if its really really bad. how far to one side are you talking?

I guess no chance of a bellhousing with the starter on the other side?

convert to top steer like that 40 series pic spence posted in spam ages ago?

Or LHD conversion so the steering is on the other side? :wink:

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Rack.jpg

Probabaly talking about 2 inchs two one side. probably even less.

Another bell housing is out of the question. possible that I could try and relocate the stater further into the block. But this would cost roughly $300, and im not that keen on that spending if I can avoid it.

Unsure on what you mean by top steer....

but yeah was discussing with leeboe on the idea on converting to left hand drive and mounting a 55 chev dash in there for lols

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Unsure on what you mean by top steer....

but yeah was discussing with leeboe on the idea on converting to left hand drive and mounting a 55 chev dash in there for lols

2 inches.... you might get away with it. would talk to your certifier first though if you are going down that route......

Top steer - I think it was some factory v8 40 series or something rare like that. the steering was acheived by rotating the entire strut assembly. the rack was mounted above the engine where you would normally see a strut brace and there was an arm on the top strut mount that it acted on. super funky. if spence sees this he might know where/how to find a pic.

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Where's the inner bush of the lower arm in comparison to the end of the steering rack body?

I'd be wanting to find a longer rack, do the same and shorten the RHS of the rack to suit... You don't want it to pivot from a different point to your lower arms.

It's not "just a wagon", it's a slammed wag with a V8 - bump steer could cause some big issues and get you in trouble.

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i'd say look at a different rack with lower profile or offset gear... how far off lining up with the factory steering shaft is it going to be when moved 2" over? it will give you more lock on one side to other but if you have lock stoppers on the hubs you can check if its hits so its not a safety issue

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To get rid of "bump steer" you need both steering arms to be parrallel with the lower arm on a Crown, and be moving in the same, or similar rate over bumps. This will never be able to occur when one arm is shorter than the other and moving from a considerably different pivot point. I'd imagine you could get it to work ok, but as you go over undulations in the road the wheels will be moving slightly independant to eachother, causing constant steering correct and a general uneasiness with the steering - so, it will be similar to driving a Crown with a crummy old steering box :P

I think the suggestion to look into other options for the steering rack is probably a good one, maybe everyone with steering racks can check them out and see whats going to be suitable? Something with the steering knuckle as far offset from the centre as possible, so if yours is 300mm from the centre you want something 350mm from the centre, problem solved.

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these are valid points.

Will have a measure of the rack i have and see how that lines up with the A arm pivots. One thing I did think of reguarding this is I could possibly "tweek" the steer knuckle on the right hand side out toward the wheel more to make the length of the steering arms the same.... Would this work? I mean, although the pivot wouldnt be in the same place as to each side, the length would be the same, there for act the same?

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you could reduce the lock or travel of the rack on both sides as much as possible then have that amount machined off the end of the rack on the affected side ?

as brad has stipulated your rack ends should be the same length and act in the same arc as your lower arm.

have you got the smallest starter possible?

needs crank handle/dragster style hand held starter? would be fn cool unless you stalled at the lights.

edit i'm thinking would only be feasible if rack is 50mm longer than pivot to pivot measurement

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Its a rear mount rack, and changing starter side is a possibilty, if I can get someone to weld it... however i understand welding to oldalloy is pretty hard/messy, and my guess is it would be even harder when the amount of oil etc that would get absorbed.

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i've cut the top off an alloy intake manifold for steel surgeon to weld a plate too,

will post his results when its gets done.

i imagine a bead blast of the weld area would smash the nasty's off ready for weld

or a 12mm sandwich plate starter mount with the bell machined back its thickness to span 3 bell bolts

and suitable triming for entry of starter?

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yea alloy is quite porus and absorbs the oil, can soak in degreaser and then try and bake it out in the oven, but usually don't get it all out, but if you have a nice BIG ac tig then you can sorta use the heat to burn/purge it out of the area your about to weld

i used to get the welder at work to do all sorts of weird stuff like sumps and i tried everything to pre-clean the bits for him, end of the day he'd just spend twice as long welding it with more heat on the first run

chuck up pics/measurements of rack, and lower arm (pivot-to-pivot) length, i can measure up a few i got lying around...

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Theres an Engineer in Tauranga who has modified the bellhousing to shift the starter on a K50 to fit a Vauxhall 1256 engine. It was flawless, could barely see it had been done from the outside and from the inside it looked tidy as well, but more visible. I'm not sure of the prep involved but its certainly doable, perhaps acid dipping the components first? The work doesn't touch any of the bellhousing bolts either, if you can find a suitable position, so strength isn't sacrificed and you could even brace the starter to the block if you were concerned about the integrity of its mounting to the bellhousing.

I can pass on his details to you if you'd like to have a talk to him.

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