Engine Building Advice
Turbo Mini Forums

Hi guys,

I am working up towards building my engine, I have built an A series before, but not for a few years, and never a turbo motor before either.

The block has been bored/honed +20, the deck has been machined to take the group a type gasket, the bottom end has fitted all three steel caps with 4 bolt centre cap, and line bored to suit.

So far I have been preparing the block to get it ready, so I have pulled the oil plugs out (4, 1 either end of 2 main galleries) and started cleaning all the swarf from the machining out of the oilways. I have also been round all the newly machined edges with a swiss file removing any burrs and just dressing the edges very slightly. I have also run a fine file over where the caps seat to ensure they seat nicely. At the moment I am trying to get hold of some decent pipe cleaners to properly clean out the oilways. I have cleaned out and re-tapped all threaded holes in the block to make sure they are OK. The block has also got new cam brgs fitted.

The crank has been to MED and has been checked for size, it is std/std sizes and checks out fine with Steve at MED.


So questions----

1) Is there anything I have missed that is glaringly obvious to the experienced guys out there?
2) Is it worth using plastigauge when assembling the crank into the main bearings or seeing as it has been measured and the mains lined bored is it not worth bothering?
3) I have always used 'graphogen' for building engines before, is this OK or can anyone recommend anything better?
4) When torqueing up the mains, what torque do you use? Also do you advise any loctite on the mains bolts? and use washers or not? Oil the threads or not?
I do need to ask steve about torque for the outer bolts on the centre main.

Thanks in advance guys, I have spent a small fortune to get the block to this stage and so don't want to wreck anything now.

Torqurin the mains - as with the head, big end, and other important torques, i do in 15lb ft increments...

Tip -
Put all the lower (upper in reality!) shells in the block (block upside down of course). Fit the shells to the caps.
A thin film of oil should be smeared over the shels and crank (i personally wipe it off the crank - leaving a very thin film).
Fit one cap at a time. tap it into place on the dowels with a soft mallet, keeping it parralel to the deck of the block. Tap down untiul clearly contacting the crank. Check bearing nip using feeler gauges, and write down for comparing later. Fit bolts and 'nip up in small stages until 45 lbft torque. Check how feely crank rotates - careful not to let move too much - you haven't fitted thrusts yet. If free, remove the cap, place back on bench, and try the next one. Crank should rotate equaly across all. Nip should be more-or less equal across all.

After all have been done, fit outer two caps and torque up to 45lbft. Fit the middle cap. This is usually where problems show. If it still rotates freely (bear in mind it shoud get 'slightly' stiffer, the more caps you fit), it's a good sign.
All ok? Remove centre cap and fit your thrust washers. I always aim for the end-float as stated in Haynes Metro manual - but towards mid tolerance.. Even 1 thou tighter than that stated is asking for trouble. Only way the check endfloat is apply a thin smear of oil over all faces - block thrust points, front and rear of thrust washer, and crank. Steel side is to block - bronze to crank. I lightly stone the rear of the thrust washers to remove the high points from where the part number / size is stamed - not too much, just to get rid of the high points. Mic up and pair the thrusts to suit - obviously equal thicknesses to the same side.
Fit thrusts. Fit main cap, and bolt down. You'll know when fitting the thrusts if they'll be too tight, and (after time) when they're too loose.

Rotate engine so crank is up/down (water pump towards ground).
DTI on top of engine, needle resting on top of crank. A large lever / screwdriver in the crank, between the mains and crank webs, you can lift the crank. Raise and drop it a few times to displace excess oil. Zero the dti. Lift crank, note the reading. Rotate crank 120 deg and repeat. Repeat again. Take average. That is your end-float. If too tight, get undersize thrusts. If too loose get oversize. Remember - thrusts come in packs of 4, but you can use two 'std' on one side of the main cap, and two under/over size on the other side of the main cap - just DON@T mix and match. If just too tight, stone the thrusts down - but i usually use a surface grinder. Don't touch the bronze side - only the steel side!!!!

Finally, once you're happy, use plastigauge if you have access for peace of mind. I've never replaced my stock since 1999 however - once you get the 'feel' for if something is right or wrong, and are confident to know how to correct things, then you trust your own judgement more.
Finally - I always check the crank run-out at the pully and flywheel taper. A crank from an 'un-named supplier' I had once had an excessive amount of run-out....

As i said - repeat the 'clamp and nip' individually for each big end (con-rod) with the crank secured in your bench vice. A single tight big-end is almost impossible to detect once assembled onto a crankshaft already installed in the block.

Incidentally, i'm just a little pedantic when it comes to building engines. I know that i take building to what some might consider an exteme, and that engines built in a quarter of the time last plenty well enough... it's just the way i do things! LOL!

Edited by TurboDave16V on 17th Sep, 2004.

This might be a daft question but aren’t the MAINS torqued up to 63 Lbs/ft and not 45 as stated in the last post ?? Or are you just using 45 as a stage on the way to 63 ??

I hope this doesn’t rub you up the wrong way it's only to clarify as allot of people use the info posted on here a fact.

Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe.

Cheers Dave for the info, I have sent you a pm to ask clarification on one point

tom the haynes metty turbo manual is really good and well worth the investment for all the torques etc

no longer a series, but still 1.3 turbo.

You are correct Doody, It's just an interim torque whilst doing the dry build... As minime says - haynes metro manual is the dogs for all torques - aswell as the best guide on rebuilding transmissions, shimming diffs, etc.

Dave. I've found that surface grinding the bronze side is a great idea. Not much, but getting it flat. This because the surface is all over the place from casting or soldering or whatever it is at the factory. Easier to get proper readings on end float when there are no high spots on the bearings.

holy thread revival!!!!

but has this engine actually rotated under its own steam yet?? ahahha

4 years!! Is that a record ?

I think I semi revived it, by linking it to the engine building advice thread!

Tom some four years on, have you finished this car yet?? LOL

Team www.sheepspeed.com Racing

Nope. 10 years on since I started, if you don't mind.......

dont listen to them Tom!

i'm at the circa 10 year point too.

Rome wasn't built in a day lads!!

I can't talk with my efforts as of late! All talk and no action.

Team www.sheepspeed.com Racing

your just a romantic jim .......................................................................
your saving it for the wedding night !

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

PMSL

https://www.facebook.com/pages/Fusion-Fabri..._homepage_panel

www.fusionfabs.co.uk



1/4mile in 13.2sec @ 111 terminal on 15psi

no I still want to nail Tom's sister!

Team www.sheepspeed.com Racing

Bastard!

pmsl

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

Team www.sheepspeed.com Racing