adaptor plate questions

Ralphh85 · Post by **Ralphh85** » Sun Apr 13, 2008 5:49 pm

box and engine are Ali, and i think the adapter plate will be 8mm thick,

my current thinking is to make it from 8mm steel, bolt it to the engine with counter sink bolts, then thread the other holes and bolts the gearbox to the plate by the threaded 8mm steel plate?

how would other people do it? and out of what material?

ali would be better from a corrosion aspect, but i don't think i could tighten it much in to 8mm ali?

and stainless i think will cause bad bimetalic corrosion?

im waterjet cutting the lot and material is "free" so cost and machinability does not really mater.

also does anyone know what thread the V8 engine bolts are?

Ralph

kiwicar · Post by **kiwicar** » Sun Apr 13, 2008 8:38 pm

if you use ali you could use helicoil thread inserts, this would let you put more load into the plate. I am just wondering how much force you are trying to clamp it together with, you can put alot of into a 8 or 10 mm bolt or two

How many bolts and what size? what thickness are the flanges on the box and engine? there is no point making the adaptor plate excessivly strong and an 8mm steel plate will be very very stiff (and a tad heavy!)
Mike

Ralphh85 · Post by **Ralphh85** » Sun Apr 13, 2008 9:02 pm

kiwicar wrote:if you use ali you could use helicoil thread inserts, this would let you put more load into the plate. I am just wondering how much force you are trying to clamp it together with, you can put alot of into a 8 or 10 mm bolt or two
How many bolts and what size? what thickness are the flanges on the box and engine? there is no point making the adaptor plate excessivly strong and an 8mm steel plate will be very very stiff (and a tad heavy!)
Mike

it wont be to heavy as its only on average like 30mm wide, tho every kg counts as its only a light car,

the holes in the box are very big, 13.9mm, not sure what thread size, could be M14, if they are i guess theres not a very big chance of pulling them out,

guess i could make an ali one and see how it goes,

im not really sure how strong they need to be, i will be using the dowls going from the engine in ot the adapter plate and also box in to the plate so its not gonna need a huge force?

Ralph

stevieturbo · Post by **stevieturbo** » Sun Apr 13, 2008 11:12 pm

I guess a lot depends how securely the engine and box are mounted into the chassis too.

FWIW, All Subarus until 99, only used 4 x M10 bolts to secure the engine to the box.

In fact...Im only using 6 to secure my LS1 to my box !! And 2 x M10 to secure engine to the crossmember !! ( Im amazed they havent sheared )

Ralphh85 · Post by **Ralphh85** » Mon Apr 14, 2008 7:48 am

well to be fair even V8's only put out 200-300 foot pounds, which isnt much torque in the bigger picture. you can put out 300 foot pounds with a 2ft torque wrench but you wouldnt sheer off 4 m10 bolts with it!

Ralph

stevieturbo · Post by **stevieturbo** » Mon Apr 14, 2008 5:36 pm

Ralphh85 wrote:well to be fair even V8's only put out 200-300 foot pounds, which isnt much torque in the bigger picture. you can put out 300 foot pounds with a 2ft torque wrench but you wouldnt sheer off 4 m10 bolts with it!

Ralph

True, but applying 300lbft by hand, covering no distance. And applying 300lbft continuosly, trying to accerelate 1500kgs of car forwards....it aint quite the same thing.

But as said....the bolts mostly supply clamping loads. Its the dowels that provide most of the location and resistance against twist etc.

mgbv8 · Post by **mgbv8** » Mon Apr 14, 2008 7:45 pm

My present adaptor plate is 13mm aircraft ally which is threaded to take the box bolts.
My last was 6mm steel with studs tapped and welded in to locate the TH350 on.
Both setups run a lot of nitrous and I've had no probs with either.
Both plates have the heavy dowels fitted.

Mark · Post by **Mark** » Tue Apr 15, 2008 10:26 pm

Mine is 16mm thick HE30 aluminium.

What gearbox are you trying to fit ?

Mark

Ralphh85 · Post by **Ralphh85** » Thu Apr 17, 2008 12:32 pm

Mark wrote:Mine is 16mm thick HE30 aluminium.

What gearbox are you trying to fit ?

Mark

PG1 (freelander/mgf/elise etc) gearbox,

i have made one from steel which i will see if its ok,

ali would have been better but even the harder grades i dont think would really take to being threaded at 6mm thick.

6082 (used to be called HE30) is the hardest generally available, but but still not good enough to thread, they are M12 bolts goign through the box in to the plate.

Ralph

Mark · Post by **Mark** » Thu Apr 17, 2008 8:56 pm

I don't know a thing about the gearbox you're using

Good luck and get some pics up

Mark

stevieturbo · Post by **stevieturbo** » Thu Apr 17, 2008 9:22 pm

It a typical fwd Rover box. The diesel versions seem to be fairly strong.

Ralphh85 · Post by **Ralphh85** » Thu Apr 17, 2008 10:43 pm

got it bolted up today if only by few bolts,

all lines up fine, can see through the starter hole the crank lines up with the input shaft.

rover put 174 foot pounds through it on a production car so should take it for my purposes.

andyes it was used with deisel's but the petrol turbo and the KV6 had the most torque. bearings are the weakest point to which is a good thing as they are easyly uprated like i have with steel caged ones.

Ralph

stevieturbo · Post by **stevieturbo** » Thu Apr 17, 2008 11:11 pm

I know someone putting over 600lbft through a PG1 diesel box, and more power than that !!! lol...

Gears hold up, the shifting mechanism isnt so hot though.

ChrisJC · Post by **ChrisJC** » Fri Apr 18, 2008 7:11 am

I managed to destroy a box with a standard Montego Turbo Diesel. I put the diff-pin through the casing........

Chris.

Ralphh85 · Post by **Ralphh85** » Fri Apr 18, 2008 9:05 am

you have just mad me happy steve, what car was it??

im pretty sure the world record for fwd 0-60 is held by a rover 200? 6 or 800 bhp or something, not sure if it was a PG1 tho.

they are pretty good boxes, and as long as nothings wrong with it then should be ok,

std diffs are good, its the type A ones like the one im running that are weak, so i might get hold of a type B torsen instead.

Ralph