Joined: Jan 2018 Posts: 107 Threads: 12
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I've a running 1935 engine and box I'm proposing to lend my godson to get his special build "over the line".
We think his chassis is a 1932, originally with coil engine and a 3 speed box, but are willing to be corrected.
He currently has a magneto engine and 3 speed box in and they fit nicely. The project has been ongoing a while (11 years, since he was 11) but his dad remembers them trying a four speed box and running into clearance issues with the cross member.
Q1 - Is a three speed box in a smaller case than a four speed?
Q2 - Is a 1932 cross member taller than 1935?
Q3 - Is there a "well known fix" such as mounting the engine half an inch higher or something?
Q4 - Other than sourcing a prop and/or a converter to connect my box to his axle (he's on that) are there any other obvious "gotchas"?
David
Joined: Aug 2017 Posts: 1,715 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
Q1 - Is a three speed box in a smaller case than a four speed? - YES
Q2 - Is a 1932 cross member taller than 1935? - YES, BUT with a high chassis crankcase there is clearance for a four speed box, unfortunately it sounds like you have a Low chassis Crankcase which has relocated mounting feet to suit the lowered drive line of the later cars, hence your clearance issues. Low frame front cross members have a dip in the centre to allow gearbox clearance.
Q3 - Is there a "well known fix" such as mounting the engine half an inch higher or something? - Its a special so you could raise the crankcase to gain some clearance but you need to be careful otherwise the drive line could end up with some funny angles and the nose piece won't fit through the radiator cowl. Probably a better plan long term to swap or alter the top of the front crossmember to a low chassis shape.
Q4 - Other than sourcing a prop and/or a converter to connect my box to his axle (he's on that) are there any other obvious "gotchas"? - As its a special this question is hard to answer but if you move things it could cause alignment issues with various other components such as pedals etc.
Black Art Enthusiast
Joined: Jan 2018 Posts: 107 Threads: 12
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21-08-2020, 08:40 AM
(This post was last modified: 21-08-2020, 08:42 AM by DavidL.)
VERY helpful. Thank you !!
The "I didn't think of that" is the starting handle vs rad shell. He'd like a starting handle but maybe not as much as having a "known good engine and box" and mine hasn't got a handle. Its a "semi race" engine (did ok with it but not fully ported, smokes a bit, drips a bit, remembering now it was my "emergency stop gap engine" but it ran well so never came out again) and in my long chassis special was mounted 5ins back and up 3/4 or something.
Alignments I'm not worried about, given "proper" prop shaft joints not fabric, and given my experience thrashing mine with the engine in an odd spot.
Peddles should be ok. Firewall clearance not an issue at this stage of the build but "a big hole" a benefit for a number of reasons with a "fitted to the installation" plates to fill in round the edges. Am thinking how in a house skirting boards and door frames are used. Alas this isn't a "up on stands with room to walk round working on it every evening" build.
For a bit of thread creep - fabric joints... Are they fine if everything is in line? Are they robust enough for tuned cars and trials etc as long as everything else is "correctly rigged"?
