4.6 rover to lt77 question...

baxterbaxter · Post by **baxterbaxter** » Sat Oct 09, 2010 9:58 am

Hi all, apologies for being straight in with my 1st post as a question but erm, im impatient

shall intro after. Basically, been sent here by oldskoolford forum. I have a mk3 capri and the option of getting a 4.6 Rpi V8 very cheap, i also have an Lt77 box in the garage, my question is this, what clutch and flywheel would i need to mate the 2 together? and is this recommened, have been told many different things, i thought the bellhousing on the Lt could only take a 9.5 clutch, but some say that may not be man enough? and that flywheels for the 4.6 are different? arghh help, me know nothing. Or is a case of totally different box? please no, im a flat broke student.

thanks in advance!

ian.stewart · Post by **ian.stewart** » Sat Oct 09, 2010 11:59 am

The flywheels are interchangable, 4.6s if from an auto may have a steel spacer ring bolted to the crank, discard that, you will also need a spigot bearing, Flywheel needed is from a SDi, unless you are intending to go for 4x4 then its the rangie bits, its all bolt up stuff

baxterbaxter · Post by **baxterbaxter** » Sat Oct 09, 2010 12:22 pm

so your saying i can just use the current auto flywheel with a manual box by changing them 2 things? thanks for the help.

unstable load · Post by **unstable load** » Sat Oct 09, 2010 3:35 pm

I think you misunderstood him a bit.
The auto only has a ring gear, so remove the spacer that makes up for the thickness difference between the flywheel and the (discarded) ring gear before fitting the flywheel from an SD1/Rangie etc as per your needs.

baxterbaxter · Post by **baxterbaxter** » Sat Oct 09, 2010 3:59 pm

definately misunderstood him.. with you now! so what flywheel would i need to use? one from a 3.9? or a 4.6 manual.. and then what clutch would be man enough? thanks again guys!

ChrisJC · Post by **ChrisJC** » Sat Oct 09, 2010 4:34 pm

There are two bellhousings that fit an LT77 to the V8, the short 'car' one, and the long '4x4' one.

All the crankshafts are the same at the flywheel end.

As I understand it, you need to get the flywheel / clutch system for the bellhousing style you have.

Chris.

baxterbaxter · Post by **baxterbaxter** » Sat Oct 09, 2010 4:47 pm

yeah that seems to be the general feedback im getting, but then would a 9.5'' clutch from an Sd1 be good enough, do they do any mega upratted ones? the engine is an Rpi one, so looking on thier site it should be 300 lb/ft, or more depending on state of tune..

ian.stewart · Post by **ian.stewart** » Sat Oct 09, 2010 6:56 pm

Clutches are a bit misunderstood, some companies will sell you a clutch thats rated for 300ft/lbs but the weight of the car will play a big part in this as will the gear ratios/tire dia
You really need to speak to a clutch company with those details so they can help with that decision, I use Helix, always been super helpful, and reasonably priced too,
http://www.helix-autosport.com/

seight · Post by **seight** » Sat Oct 09, 2010 7:37 pm

Don't some of the 4.6 cranks have the bit that holds the spigot bearing much longer than others and you need to 'shorten' it otherwise it jams on the box input shaft? Or am I confusing things even more by talking boll*.

FWIW I think just about all Westfield V8s have 9.5" clutches, but they are light cars. A Capri isn't that heavy is it?

By the way, welcome to the forum.

Mike

kiwicar · Post by **kiwicar** » Sun Oct 10, 2010 5:53 am

Hi
Don't get too worked up about diamiter of the clutch, using the right combination of material and plate pressure can more than compensate for 1" less diamiter. 820 bhp nascar lumps weighing a ton and a half use 7" twin or tripple plate clutches with no slip issues.
Best regards
Mike

JP. · Post by **JP.** » Sun Oct 10, 2010 9:04 am

Is nice to see to here too so my advertising did work

10.5" clutch systems will fit inside a 2wd LT77 gearbox. Only had to modifie my SD1 flywheel to accept the larger clutchcover ( redrilling the holes that holds it and drill out the studs that fixate it) and thats it, otherwise it was a straight swap.
Have a Mc leod street/strip kit in it from Real Steel wich has a sinterbrons/organic facing.

Capri's aint heavy but more than 200 bhp will deffo be a problem with the standard SD1 clutch system. Capri's with a RV8 are usualy around 1150-1200kilogram weight. Capri's where light on papers........but not in real.

Helix does have straight swap 9,5" systems that will cope with the torque.
Thought Tony had experiance with AP 9.5" clutches.
The clutch cover is the most importand part as it does 75% of the job. It has to hold the plate fix'd against the flywheel so just switching plates aint going to work.

Be shure your flywheel has no cracks ( very common with SD1 ) and has an absolute flat surface or have it resurfaced before you start. The flatter the flywheel is the more grip it generates.

Post by **Coops** » Sun Oct 10, 2010 9:15 am

im running a hybrid clutch from AP now,
told them what i wanted to use it for etc, and they matched a cover and plate, which so far is holding up very well,

can findout the invoice with the part numbers if interested? was £450 though

ap clutch listings here:
http://www.v8forum.co.uk/forum/viewtopic.php?t=3521

http://www.v8forum.co.uk/docs/ap_clutches.pdf

baxterbaxter · Post by **baxterbaxter** » Sun Oct 10, 2010 12:15 pm

haha, it worked indeed JP, feel like part of an elite club now, even tho im not getting the engine till later today.. LOTS of useful help here guys! at the moment i think my best option is the real steel one, works out about £250 all in, trying to do it as cheap as possible, im a poor student who thought it would be easy to do uni without a loan...

I know doing things on the cheap is never the best, but if i can get it done this year i can pass it off as a uni project, ideal. Next question, any one know of any Sd1 flywheels for sale..