dry sump oil input location Fiat dohc

Competition engines and 'live' projects only. Good photos to illustrate your post are expected.
Post Reply
Beek
Posts: 9
Joined: July 4th, 2012, 6:37 pm
Location: Clermont, Florida
Contact:

dry sump oil input location Fiat dohc

Post by Beek »

I am in the middle of a Fiat engine project where I am installing dry sump lubrication to this engine. This is a 2.0L 8 valve U.S.A. spec engine. My question is instead of pressurized oil entering the engine where it normally would from the oil filter return. Supplying the engine with oil thru the mail oil galley fed from the front of the block. Would this not give "priority main bearing oiling"? Are there any reasons I should not feed oil into this location? I do realize I will have to block off the oil input on the filter side.
003small.JPG
003small.JPG (92.02 KiB) Viewed 6221 times
By placing the fitting shown in the area shown by the arrow.

I would also like opinion of scavenging oil from the cam housings and not let the oil return into the crankcase by flowing down the side of the crank case. My intent is to keep oil splash from the rotating assembly.
GC approved
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: dry sump oil input location Fiat dohc

Post by Guy Croft »

Trust me - It just does not matter where you feed the oil in - provided you have sufficient flow and pressure.

Attempts to alter the behaviour of the oil bath lubrication in the head are liable to 'wipe out' the cams..! Scavenge from the sump.

I see you have painted the interior of the cracnkcase. It's your engine so your liability, but I would never paint internal parts. Inevitably there will be paint loss and that has to go somewhere. Fact is - once the engine is sealed up you will never know till strip-down whether it has adhered or not. If you want better drain-down - strip it off and polish the interior. Cannot say I would go to those lengths but there we are...!

Hope this gives you the reassurance to proceed.

G
Guy Croft, owner
Beek
Posts: 9
Joined: July 4th, 2012, 6:37 pm
Location: Clermont, Florida
Contact:

Re: dry sump oil input location Fiat dohc

Post by Beek »

Guy,
Thank you for the input. I will keep the oil feed as usual then. Some of my performance buildup experience is from the NASCAR world, Here on American v8 engines we have to alter the route of oiling to better oil the main bearings. Granted in all of the Fiat engines I have built none failed due to improper oiling other than aerated oil. I do intend to use a crank scraper and a windage tray too. The "paint" on the inside of the block is "glyptal" I have used this for over 20 years with no problems of it coming off. We have used it in all of our 850hp NASCAR engines as well. Never have I seen it come off. Granted it is applied properly too. The block was polished before the paint was put on, the oil returns were deburred as well. The problem I have is the oil returning down the inside of the block getting hit by the crankshaft and rods, further aerating the oil. As I have been led to believe this also diminishes horse power too. I will not alter the camshaft oil bath and oiling, but can I return the oil externally to the sump? Or am I "splitting hairs" trying to improve on the oiling? Again I very much appreciate you input.
GC approved
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: dry sump oil input location Fiat dohc

Post by Guy Croft »

Thanks for your considered reply Beek, I had a feeling that the paint would be something special so thanks for briefing me on the internal prep.

To be effective a dry sump pan has to have certain characteristics - one of which is a windage tray of course. See photos. As for adding a scraper too I have never done it and simply do not know what benefit you will see.

A lot of dev work has gone into the issue of windage losses in recent years esp in F1 engines. When I left FI in the later 90s the 'big thing' then was tribology... So one is seeing reduction of losses and power gain rather than trying to get more power per-se by ingesting more fuel.. So in that sense you are certainly on the 'right lines' with your work.

The TC definitely does not have a drain-down problem with the head so don't attempt any mods there other than a thorough deburr of the drain-down regions..

G
Attachments
full-form windage tray - small gap (about 5mm) takes oil thrown by the crank into the scavenge channel
full-form windage tray - small gap (about 5mm) takes oil thrown by the crank into the scavenge channel
pic 004.jpg (35.91 KiB) Viewed 6142 times
shorter scav channel on this dry-sump pan for a Fiat 131 where the rear of the pan has to clear the X member (as with 124 Spider) but still room for twin scav outlets
shorter scav channel on this dry-sump pan for a Fiat 131 where the rear of the pan has to clear the X member (as with 124 Spider) but still room for twin scav outlets
IMG_3360.JPG (66.73 KiB) Viewed 6142 times
shaped windage tray in position
shaped windage tray in position
IMG_3364.JPG (65.34 KiB) Viewed 6142 times
Guy Croft, owner
Beek
Posts: 9
Joined: July 4th, 2012, 6:37 pm
Location: Clermont, Florida
Contact:

Re: dry sump oil input location Fiat dohc

Post by Beek »

Guy,
How much clearance do you recommend between the crankshaft weights / rods caps and the windage tray? How much gap do you recommend for the opening of the scraper? If you have no issue I would like to copy your pan design. The application is for a Lancia Scorpion / Montecarlo, therfore oil pan clearance is no issue. I will Start a build thread as soon as i have assembled all of the parts needed.
GC approved
Guy Croft
Site Admin
Posts: 5039
Joined: June 18th, 2006, 9:31 am
Location: Bedford, UK
Contact:

Re: dry sump oil input location Fiat dohc

Post by Guy Croft »

The crank webs or rods should be as close as you can get them allowing for compression of the sump gasket.

I suggest you forget the scraper, I have never heard of the need in a ds application

G
Guy Croft, owner
Post Reply

Who is online

Users browsing this forum: No registered users and 29 guests