SD1 crankshaft pulley in performance use?

kokkolanpoika · Post by **kokkolanpoika** » Wed Jan 09, 2008 7:34 pm

Just curious..

What do you guys think about using std SD1 crankshaft pulley to "race" specks 5,2 stage 4 engine.. Is it suitable for +6500rpm and about 370hp/600Nm aplications?
I have read that tolerances of crank and bulley is not as good as it should be? It is too loose in crank?
My crank is Forger item, and i have got std SD1 crank bulley in my ex 4.6 engine.. Pulley has got lot of miles behind, about 247590 miles..

So is it finish/caput?

I dont get acquainted with those pulleys yet.. so that those pulleys is new think for me..
I only build and fix if it necesary..

But now i want to make strong engine..

Post by **katanaman** » Wed Jan 09, 2008 7:57 pm

So long as the rubber bonding between the inner and outer parts of the damper is good I cant think of any reason why you cant use it.

RoverP6B · Post by **RoverP6B** » Wed Jan 09, 2008 8:01 pm

According to Des Hammill's book, the standard damper which accompanies the pulley is suitable for applications up to 5500 rpm.

J.E Developments stock competition type dampers for up to 5.2 litre Rover V8s, 360 ft/lbs torque and 400bhp, reving to 7000rpm.

The pulley must be a tight fit on the crankshaft snout, requiring a puller to remove, and a press to refit.

The pulley is non servicable, and should it be a loose fit, must not be used, and a replacement obtained.

Hope that this helps,
Ron.

Post by **katanaman** » Wed Jan 09, 2008 9:17 pm

I don't see what HP has to do with a front damper or pulley, its not like your driving the car with it. I have never ever seen a damper on an RV8 be so tight it needs a puller unless rusted on and I don't see any reason why on this engine it would serve any purpose. A press to fit? I can't see any reasonable way to do this on a built engine. It's the pressure between it and the crank that largely keeps the crank sprocket from moving. If you make it tight on the crank your running a risk of not tightening it up fully so the sprocket will fret and you can guess what happens next. I agree there shouldn't be any play but tight I don't get. A performance damper could be a benefit if the vibration has changed that it damps out and higher than normal RPM could be that reason. In practice though many people use the standard item and have no problems even at high rpm.

Post by **katanaman** » Wed Jan 09, 2008 9:53 pm

Does the book say why it should be so tight? Been sitting thinking about it and still don't get it lol

kiwicar · Post by **kiwicar** » Wed Jan 09, 2008 10:05 pm

I would have thought you would want a precision fit ,ie.. not loose, but also not an interferance fit, an exact fit on the crank snout. Interferance fit would put stress on the keyway slot initiating cracks, loose and it could seat differently each time the bolt is tightened up, not going to happen often but not the same when ballanced and final assembly.
That is what I'm going to aim at anyhow.
Mike.

RoverP6B · Post by **RoverP6B** » Thu Jan 10, 2008 9:43 am

The book states and I quote.."Many standard dampers are in fact a loose fit on the crankshafts and, as a result are not servicable items and should not be used. They MUST have an 'interference fit' on the snout of the crankshaft (this means that the damper has to be pressed on the crankshaft and drawn off using a puller). If the fit is not tight enough (the damper bore must be between 0.0007 and 0.001in smaller than the crankshaft snout) the result could be a ruined crankshaft and damper." unquote.

seight · Post by **seight** » Thu Jan 10, 2008 10:18 am

I just don't get that in practical terms.

How on earth could you press fit a damper with the crank in the block and the timing cover on?

And how could you fit a timing cover with the damper already attached?

Mike

ian.stewart · Post by **ian.stewart** » Thu Jan 10, 2008 10:37 am

Ive been using a stock damper for years, regularly seeing 7000rpm, as for the slip fit on the crank I have allways used a dab of Loctite retainer just to make sure the pulley does not come loose and a dab of threadloc on the bolt as well, its a bugger to get off again, but its never come loose!!
What I also do is Fit the key, on most occasions the key is slightly loose, but I make my own and spend half an hour of filing to fit to a slight interferance fit

minorv8 · Post by **minorv8** » Thu Jan 10, 2008 4:35 pm

Fitting a press fit damper is not rocket science. Actually it is a commonplace in Chevy SB/BB engines. You have a threaded bar that is screwed into the crank snout (where you normally fit the pulley bolt) Then you fit the pulley/damper on the crank, then a big washer and nut. Tightening the nut will push the pulley in.

http://www.atiperformanceproducts.com/p ... /index.htm
http://www.thedieselpage.com/features/fluidampr.htm

Then there is the high tech version:

http://www.webster-industries.com/Damper_Puller.html

Post by **katanaman** » Thu Jan 10, 2008 4:51 pm

minorv8 wrote:Fitting a press fit damper is not rocket science. Actually it is a commonplace in Chevy SB/BB engines. You have a threaded bar that is screwed into the crank snout (where you normally fit the pulley bolt) Then you fit the pulley/damper on the crank, then a big washer and nut. Tightening the nut will push the pulley in.

http://www.atiperformanceproducts.com/p ... /index.htm
http://www.thedieselpage.com/features/fluidampr.htm

Then there is the high tech version:

http://www.webster-industries.com/Damper_Puller.html

Yep but that's a chevy, I have never seen this on a Rover engine. My Ford 351c wasn't like that either.

minorv8 · Post by **minorv8** » Fri Jan 11, 2008 12:15 pm

It is irrelevant which engine you have, I was merely stating that there is a simple tool for installing if you have an interference fit.

mgbv8 · Post by **mgbv8** » Fri Jan 11, 2008 3:28 pm

My original RV8 damper was fine for Drag racing. I had it dyno'd to 7400 rpm. And during an "incident" the engine went up to nearly 9000rpm.
I only changed it for the SFI one from Real Steel as the rubber bit looked a bit cracked. Even my original damper is a snug fit. It doesnt slip on without a little shove. And after 1 year of solid Podding it was still as tight as wotsits to undo. I think its 160ft/lbs to do it up isnt it?
Mine never comes loose.

RoverP6B · Post by **RoverP6B** » Fri Jan 11, 2008 6:27 pm

The torque for the crankshaft pulley, as specified within the workshop manual for 4.6 litre engines, is 200ft/lbs!

That is seriously tight!

kokkolanpoika · Post by **kokkolanpoika** » Fri Jan 11, 2008 7:24 pm

RoverP6B wrote:The torque for the crankshaft pulley, as specified within the workshop manual for 4.6 litre engines, is 200ft/lbs!

That is seriously tight!

200ft/lbs

I read haynes SD1 owners workshop manual.. the torque for the sd1 pulley is 140-160ft/lbs..
I use this settings when i build my 4,6 with sd1 pulley..

I also wonder now, what torque settings i have to use with FORGED RV8 crank and sd1 pulley? Same as original crank/SD1? or same as 4,6??