1974 Mgb Ford 302 swap Steering rack interference

Started by danielruhe, May 24, 2019, 06:00:51 PM

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danielruhe

Hi guys,
I am new to the forum and this is my first post so please guide me in the right direction if this is the wrong place to post this.  I have a 1974 mgb roadster that I am doing a 302 swap with.  My engine is just about ready and I am wanting to get things set up in the engine bay as best as I can ahead of time.  I am aware of the interference with the harmonic balancer and the steering rack, especially on the early chrome bumper cars such as this one.  I am curious if its best to place the engine with the steering rack between the oil pan and harmonic balancer the way the rack is and have the engine be set high up in the car and have to weld on a hood scoop to allow the hood to close over the air cleaner.  Or my other option is to lower the steering rack and then flip the tie rod end upside down to keep the steering rack similar to stock angle with the upper and lower control arms.  I am worried that this might cause bumper steer and end up having a car with sloppy handling characteristics, but I believe flipping the end will correct this. .  Has anyone ever lowered the steering racks for an engine swap? Also, I am open to any other ideas of how to address this problem.  I want to use the stock early style rack as it has less turns from lock to lock than the later models, I plan on using the shorter later model steering column, and use a series of intermediate shafts and universal joints to connect the two. I attached two pictures, one is the underneath of an mgb which has a lowered column and the other is paul shil's mgb and it appears he did the engine swap with no hood bulge and no hood modification with an early style rack and crossmember. Any information you can give me the better.
Thanks,
Daniel
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Jim Stabe

Daniel - When my car was powered by a 215 Olds Jetfire I faced the same problem. I wanted the turbo to be under the stock hood with no bumps or scoops. The MGB has bump steer to begin with and lowering the rack just accentuates the problem. What I did was to narrow the rack so the inner tie rod pivots were in the same plane as the upper and lower A arm inner pivots, the upper A arm being the lever shock. I then swapped the steering arms and bent them so the tie rod ends would clear the wheel and the tie rods were parallel with the lower A arms. When I modified the steering arms I also removed the Ackerman and the result was substantially increased front end grip, The down side to no Ackerman is when making a U turn at full lock the inside tire would slide if the road surface was slippery (sandy or wet). With the rack narrowed and lower, the stock steering shaft wasn't pointed at the firewall penetration any more. I cut the shaft just above the rack and installed a second U joint and made a shaft to connect with the stock upper joint.

Sorry I don't have any pictures, all that work was done 45 years ago.

ex-tyke

QuoteI am open to any other ideas of how to address this problem.
Find a RB front xmbr - that extra inch of height will allow the steering rack to fit between the damper and oil pan and keep your engine low enough to allow the stock hood to close. Both the CB or RB xmbr will require rework to add sump clearance. Whether you address the small bump steer issue is up to you but it's not a show stopper.
As far as the quick ratio steering rack, MG did make a 2.92/1 ratio for a RB front xmbr - I assume that it came from a mid change year (74.5 or 75?) - I have one, so they do exist. A steering rack mount modification maybe necessary to get the rack shaft angle correct to mate to your steering column (and even a shaft length mod ).
All doable, depending on how far you want to go to get a satisfactory result.

40indianss

IIRC flaming river has a new product called a VDOG for helping with tight and/or difficult steering shaft angles when double universal joints may not be the answer or applicable.  Could be pricey however

MGB SS

I lowered my rack, swapped the steering knuckle (just part that the tie rod fits into, they bolt on) from side to side and have my tie rod ends pointing up.  Tie rod arms sit perfectly flat.  Couple of good picks of the rack and how it sits with the motor (5.0 Ford) in my:   "How it was done" article.

http://www.britishv8.org/MG/JoeSchafer.htm

danielruhe

I want to stay away with having to move the steering rack if possible, but I want to know it that would be an easier route to take than trying to fir the engine with the stock rack location? I want to almost identically copy paul school's mgb but I want to know how he was able to use the stock front crossmember and it appears to have an unaltered steering rack and a hood with no bulge?  Everyone says that you have to use a later style crossmember, but it appears he did not.
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ex-tyke

QuoteI want to almost identically copy paul school's mgb...
Assume you are referring to Paul Schils
http://www.britishv8.org/MG/PaulSchils-MGB.htm
Looks like Paul has incorporated a second u-joint in the steering....you could send him a PM for specific details or see him in person at next week's show in Wytheville.

302GT

Just to add some more options:

The new replacement steering racks are quick ratio for both chrome and rubber bumper cars. in fact, the ratio seems to be slightly faster: about 2.5 turns lock to lock.

To lower a rubber bumper front suspension it is best to use drop spindles so as to retain full suspension travel. Available from:
 http://www.mgbracing.com/.

MGBV8

And, IMO, that faster rack may not be a good thing.  It will make the steering heavier & make the car twitchier at speed.

302GT

I now have one of these racks; always trying new stuff. The ratio is actually about 2.7 turns lock to lock. Steering is somewhat heavier than with a rubber bumper rack (3.5 turns lock to lock) but it is not unreasonable. I do have caster reduction wedges however.

Steering is very stable at speed which is mainly a function of the self-centering action caused by the caster angle. Even with reduced caster, centering action is still strong. This is indeed a viable option for those who want faster steering with a rubber bumper crossmember.

danielruhe

Im looking more to answer the question how he was able to use a chrome bumper crossmember and not have harmonic balancer/hood closure issues? I appreciate the information on the steering rack though.


psmg

Daniel, When I did my conversion I moved the steering rack 1/2" down and 1/2" forward to provide clearance for the harmonic balancer. After doing this, I had to have the steering arms bent to eliminate  bump steer. Not a big deal if you have a GOOD alignment shop available that knows what they are doing. Makes a big difference. I'm including pics to show what I did.
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