Lightspeed have just let me know that the engine is all ready for me to collect. $7500 CAD in parts and labour to strip down, rebuild and repair head, new crank, pistons, valves, rebore and rebuild.

However I've decided I'm not happy with the use of washers on the piston pin and want to use different conrods instead. They are going to get some custom made ones from Carrillo in USA. $400 USD a rod but only a 4 week turnaround. These will use the existing bearings and will be 22mm at the small end and 26mm at the big end.

Now I need to order a new set of shells, head gasket and head bolts

John

I've been in contact with Arrow Precision Engineering who are making Trevor's rods. They asked would it not be better for them to leave the big end width as standard, so you don’t need to have the crank machined, and then make the small end width to suit your pistons so that the rod is then piston guided again?

I've received an email back from G&G Motorsport saying the crank will not need machining in any way. They will be a direct fit to the CP Pistons. Regarding crank or piston guided, as the pistons are of a slipper design with very little skirt to absorb thrust forces and side loading it will make much more sense to guide the rod from the crank end.

John

Just make sure before you get any machining work done that the rod journals are central to the bore, its quite possible that they are offset in which case you will need to offset the width of the big end on the rod to one side

In your setup you have no choice but to convert your engine to a crank led setup, the forged pistons and rods will not have any kind of bush where the small end touches the piston pin boss so you cant do that.

also have you got a quote for a after market crank?

if you go this route you could have the journals made to the width of the rod, not to mention an after market crank will be much stronger and you can get some parts of the design improved, for example having proper radii at the edge of the journal rather than the sort of channels that are on the O/E crank, this will improve the reliability of the crank led design aswell in my eyes

And it May be cheaper to go for a crank rather than the rods

have a look here

http://www.scatcrankshafts.com/

click on the custom billet crank button on the left

I have worked with one of there cranks before and the quality was very impressive for the money, not as good as Farndon or Arrow but not far off and quite a bit cheaper, and it will be multible times stronger than the O/E item and much better finished

this is the way i would do it but you need to make sure the journals are central to the bore before you do anything

Ricky

IMHO, you cannot say something is stronger just because it looks nice. Unless you have material spec for both items you are only guessing. Now I'm prepared to guess the std crank is forged steel then nitrided if it is similar to the 16v 2.0 crank. Now someone let me know if I'm wrong but I'll assume the 5 cylinder crank to have all of the crank throws at a different angles to the adjacent one, somewhat more complex then a single plane 4 cylinder crank, as it would have to be machined in phase or twisted to be in phase. Add to that the CAD work to come up with this one off design then I cannot see how it would be possible for such an item to be at comparable let alone cheaper cost then the rods. I've not heard of cranks breaking in well maintained 5 cylinder Fiats thus I would say the std is probably suitible up to all but the highest end lowest weight projects (yet to see anything like that). Incidentally another guess without looking but these grooves next to the journals I imagine are recessed rolled fillets on a radius thus not a stress raiser like a corner would be. This method perhaps also assists in production costs campared to an 'in line' fillet radius (?).

rich

scat stick to a set price with custom cranks and it may not be cheaper than the rods but there will not be much in it

As you have said I would think the standard crank is forged steel but it's unlikly to be EN40 or 4340 chromolly, it will be cheaper material and thus less sturdy

The main reason I suggested the after Market crank option was mainly to be able to narrow the journals but also for the proper rolled fillets rather than the recessesed items found on the O/E crank, it just seems wrong to me in a performance application

It just seems better than trying to run potentially a piston led setup converted to a crank led setup, especially as the pistons and rods that are being used have been designed for a crank led setup, why not get a crank made for a crank led setup as well?

It's all my opinion of course but one thing is for sure and that is that before any decisions are made every option should be checked out prior to any maching work being carried out

Are you talking about a Ferrari engine modification or is it still a FIAT engine?
The sky is the only limit!

Ricky, please email them and I'm prepared to bet that they will not honour any current pricing structure based on an even number of cylinders. Oh if it's (20v crank) like the 16v crank then it will be EN40b; and 'sturdy' isn't an engineering term I know of

Ok so we have come to the conclusion that it may or may not be made from a good strong material like en40b!

By design though it's not in my opinion the best way to go as the rods and pistons being used are not to O/E spec and changing the crank design would cure the problems here

As for cost, well he is going to be paying $1600 (can) for the rods you can get custom made cranks from around £1100, so let's say he is going to be paying roughly $2000, so for about $400 more he will have a setup that is superior, it doesn't sound to bad to me but of course it's upto the owner

I'm just trying to put another possibly better option ahead

The rods are a lot more than that! $400 USD each x5 = $2000 USD or 1400 of your UK pounds

Sorry I rushed through that in my mind and thought it was a 4 pot, but it backs up my theory on a new crank as a possible option

its worth getting a quote at least, there are plenty of other crank manufacturers that may be more competative on price as well but Scat seem to be very good value for money

Ricky you are still guessing they would even entertain a one off 5 cylinder crank. Which maybe they would be for not anywhere near the guesstimates you're making based on items they are tooled up to make. Its not a viable alternative based on a guess, and it would take a bit of ground work to get a decent estimate, look at DKE's estimation form for example.

I agree its a bit of a guestimation but its definetly worth getting a quote, they do mention on there site that they can make any kind of crank and to quote there web site

"specialized race, prototype and industrial engines
Available in a variety of materials and styles "

and

"SCAT can manufacture cranks for any application up to 40" length and 10" diameter "


As i said its worth getting a quote

I agree with Rich re the idea of making a custom 5 pot crank. I looked into it seriously because with a 2.4 abarth block you can make a 2.6 which will still rev to 7800rpm.

I believe that the piston-to-rod interface is unlikelyto be the cause of the problem but an effect of a problem which is related to a lack of oil or oil pressure. The oil pumps are not bulletproof, and a bottom end failure that causes an oil pressure frop may also have the same effect

When I had the engine assembled they stripped the oil pump down and checked it was all within the allowed tollerances.

Having said that this time I've fitted a brand new FIAT pump to be absolutely sure.

John

All im saying is if the crank can be made for a reasonable price then its seems a very good way to solve the problem of the rod walking, although im not specifically saying that the crank was the cause of the original problem

What is quite clear is that Tipoboy wants to stop the chances of the rod walking, the crank option that i have suggested is a viable option if the costs are not to high

Ok, sorry to bring this up, but I'm going to be closing the engine soon so I would like to know.

I have Accralite/Farndon combination (2.0 20vt). I bought new oil pump (even though mine is ok) and will be using a SA ecu.

So basicly if the oil pressure is good, the rod will be centered without possibility to "walk"?

What is the other option? Teflon washers? Who should I search to make me those? Machine shop doing the block boring or? ...

dearon, don't waste anytime or energy on this, you don't need to do anything, your setup is tested and proven to work perfectly as it is

my thoughts exactly, but had this topic in mind.. especially someone wrote: no need to strip down a running engine, but if building new one add telfon/aluminium washers..

thanks

Just seen this interesting thread. I had a custon crank made for my 16v engine, the company had a firm price on custom cranks and certainly came up with the goods. Catered for my every whim, delivered on time, changed at no extra cost details near the end, finest vacuum remelted E-4340 and nitrided twice, once before final polishing and again after. To my knowledge there's only one other company to better them and they are a closed shop.
http://i3.photobucket.com/albums/y85/1NRO/Eightweightassembly014.jpg
http://i3.photobucket.com/albums/y85/1NRO/Eightweightassembly015.jpg
It cost me nearly $3000 this time last year when it was a goood exchange rate, they didn't seem bothered what kind of crank it was. The price could of been bettered by other custom crank manufacturers but I wasn't in the market to be taking risks though some of the other places were very nearly chosen.

who was the manufacturer? Farndon and arrow are regarded as the best crank manufacters in the world although there are quite a few that are almost as good but quite a bit cheaper

They are good manufacturers both Arrow and Farndon but they are not the best in this world, not even in this country,MCT would be better for instance. There are quite a number of places who wouldn't let you through the door unless you were waving big development budgets under their noses,if at all. Others who wouldn't do you a custom one off unless you were very well connected who do production of mainstream cranks which are of exceptional quality, Bryant for instance. Scat might well be cheaper but thats due to most of the manufacturing of their product taking place in china with only the final finishing done in the States, they produce a reasonably stable level of quality due to this. Eagle on the other hand don't do any crank work in house, it's a finished item from China and consistancy doesn't come into it. It gets worse still, recently there was an ebay seller offering a "billet crank" which just shrieked China, an amateur who's gone to China to source a product was my opinion, the crank didn't even have oil drillings! It was only a cool grand so it must of been good

My crank came from the manufacturers, I met the man who designed it ready for production for me and the guy who stood on the shop floor who would be responsible for actually making it. They aren't the best in the world but IMO they are the best company in this world to make something like this for me, Joe public. The accuracy is correct to ten thou at any point I've checked. It's a little spooky, a finger nail draged across one of the weight makes it ring long after it's been removed. My only regret is not having the courage to tamper with the stroke, it did my head in specifying what I have without taking further risks, something for the future, I would like to build something with a lesser stroke. One thing you do need to do when this route is chosen is come up with the specification that YOU want, I've not come across anyone who would just make a crank with no detailed instruction. I had the same company make the rods as these are unique to the crank, this helped the risk factor as I had the piston specs by that stage. It all fit thankfully but the adrenalin was pumping when it all arrived and I tried it all in a block, a less polite version of phewww was clearly heard

I get your point but I was referring more towards the run of the mill stuff if it was a f1 engine or something of that ilk then pankle would be first on the list for me, I have been told that most f1 engines use pankle rods and cranks but I have never seen one to see what they do better than any of the other manufacturers

A couple of pics from my collection of F1 bits, both made by Pankle

http://i3.photobucket.com/albums/y85/1NRO/panklecrank.jpg
http://i3.photobucket.com/albums/y85/1NRO/pankle.jpg

anything jumping out at you?

Sure the DKE stuff must be well made, couldn't help thinking the capricorn item hadnicer fillets. Who makes the best - depends who's paying the bill for sure.

Nik have you run your crank design yet, or is it all part of the larger project you are working on? Just interested to see your opinions on your own work when the time arrives.

Hi Rich,

Not yet I haven't, still buying / making parts with quite some funds to find yet. For sure I'll tell the story as and when I run this engine, maybe a disaster looming but that'll not deter me having a go. Maybe I'll run all the bearings inside of an hour or maybe it'll go some. Either way I'm unlikely to stop at the initial build, I've lots I'd like to try.

Nik