Sump / oil system modifications?

[Almac_Sabre]

Hi Guys,
I've just had the front connecting rod break in my 1UZFE ... well explode is probably a better description! It 'let go' in a fairly major fashion, punching a hole through the side and top (in the 'V' under the TB) of the engine block.
The engine has recently (3000km ago) been totally rebuilt and mildly modified for racing, with heads shaved and ported, and 8 throttle bodies added. It puts out 195kw @ 6000rpm at the wheels.
The guy who built the engine (he's very experienced with 1UZFE engines), and who is now rebuilding the engine, believes that the 'blow up' was caused by oil surge / oil starvation to the rod bearing. He believes that the bearing seized, therefore putting huge stress on the rod, causing it to break.
He suspects that the oil starvation is caused by the modified sump (made very shallow by the previous owner to fit into another car). This shallow sump may not hold enough oil, and we think is susceptible to oil starvation when the oil is pushed forward / back & sideways during heavy braking / acceleration & corning. This is despite a pressurised aqua-sump being fitted.
When we rebuild this engine we want to modify the sump (wings / baffles etc), but unfortunately we can’t go any deeper. The bottom of the sump is currently level with the bottom of the bellhousing.
Does anyone have any ideas / thoughts on the best style of sump to avoid oil starvations? We do not want to dry-sump, so are looking for the best way to modify what we already have. We will continue to use the aqua-sump.
Thanks in advance for your help.
John
PS : Check out http://www.spr.co.nz/raceteam.php for details on the racecar.

 

[gloverman]

I have seen this many times with race cars and small sumps. Often #2 from Memory. One of my customers did his doing do-nuts in his surf. Is there room to go sideways? Also good baffles are a must. Do you have another block? As I could part with a late model block ( lighter rods and pistons , different crank.) I also have spare early rods and pistons if you need - Cheers

 

[striker]

the sump you're descibing is not something I'd want to run.
if you cannot make it bigger and lower than it is now, I'd think again about adding an accusump.

before you try to make a sollution that doesn't fix the origin of the problem you have, you might want to look to save the dollars on the accu-sump system, and build a dry-sump system that uses the original oilpump in the lexus engine for the presure stage (it's of very good quality and should be adaquate for you're needs)

so make a drysump sump, with 2 or three scavange ports, and inlet to the original pick-up pipe entry.
a 2 stage scavege pump from Aviad or something (not to expensive)
and a 8L drysumptank, plumb it all in and be done with it forgood.

this actually is not that expensive, if you look hard enough for your parts suppliers.

or maybe Erol Richardson can make you somthing, that fit's right away?

regards thomas

 

[XR8tt]

Was the rod just broken ? Or where the bearings nipped up or scuffed from no oil??? I would have though there would be signs on other bearings also ??....Could have been built with too tight clearances ??
It's an easy excuse for the engine builder to make...
I'd fit some wings and trap doors to sump... Double check tune...

 

[Almac_Sabre]

Thanks gloverman, striker & XR8tt for your very useful (and fast) feedback.

1. gloverman - thanks for the offer of parts, but Andy Culpin from RaceFX in Auckland has given me a short-block that he had left over from another project.

2. striker - good suggestion Thomas. I also don't like the small sump that the previous owner designed, but I've raced this engine for 3 years with no problems. The aquasump that we have always run must have done it's job ... up until now! But with the increased horsepower, higher top speed & cornering speeds, better brakes, and wider tyres, the oil system has not been able to cope. I'll do some more research, but may try a modified sump before going to the expense of dry-sumping.

3. XR8tt - I haven't seen the dismantled engine yet, just spoken to the engine builder, but he says that the rod is in multiple pieces and the #1 bearing is in the bottom of the sump. The #2 bearing is also stuffed. You're right about wings, baffles & trap doors ... I'm definitely going to do that! I think I will also lower the skid-plate / sump-guard by 20mm so that I can increase the depth of the sump by 20mm. I'll also check out the aquasump to see if it is operating correctly ... sometimes the air pressure drops below 40lbs.

Thanks again for all your advice,
John

 

[gte]

Check the skyline forums, they mod their sumps for a larger capacity to hold more oil, and I think you could take a page from their book

 

[Almac_Sabre]

Check the skyline forums, they mod their sumps for a larger capacity to hold more oil, and I think you could take a page from their book

Thanks for the advice - I'll check it out. The more I think about it, the more I realise that a winged, baffled sump is definitely the way to go. Don't know why I didn't do it originally ... especially since I've installed this type of sump on other racecars I've owned!
Cheers, John