chris-m

any engine builders/tuners able to offer advice on this one please?

i have a forged ls6 in a kit car used only for track days /sprints. the engine has been run in on mineral oil asadvised by builder, using 15w-50.
was advised to stay well clear of synthetic oil during the break in/running in period.
i did about 20mins/50m running in to cycle the engine, then droped the oil and changed it with new filter. since then it had about 100 miles on it driven quite hard on fresh oil. after that i did another oil swap at the start of last season (same grade) and caned the engine hard to the redline so it's definately run in hard now. its since done about 300miles on track last season.
its not time to get ready for this season, what weight /grade/type oil should i use. is it safe to use synthetic oil now or semi? or stick with the mineral?

i run 2 oil coolers and a dry sump so the oil has never gone above 100c on track. the engine runs great, uses no oil, and i am expecting to drope down a grade now to maybe 10-40 or even 5-40?
any advice appreciated.
have emailed same question to original builder but awaiting reply so far.

chris-m

bump back up if anyone can advise

WKMCD

iTrader: (2)

I'd run what the builder told you to run. They are the only person that knows what clearances were used during the build.

Just my $.02

chris-m

thats the only slight problem, they said to run mineral oil during the running in period and first few hundred miles, which i've now done. they advised not to use synthetic till then. i have emailed them asking the same question but no reply. (Weber race engines). i'm in the UK so not so easy to ring them to ask you see.

WKMCD

iTrader: (2)

I don't see a problem running the same weight synthetic oil. It will give you a little more protection from heat.

Is this for the GD T70? VERY COOL!!! Post some pics.

chris-m

i might give them a ring to reassure myself as i blew my last ls1 up and cant really afford any damage to this new engine. :-)

heres my photobucket link with the car in it.
http://s398.photobucket.com/albums/p.../GDT70%20Lola/

and a short vid of a launch. (on the old ls1, the day it blew up lol)
http://s398.photobucket.com/albums/p...t=MOV01277.mp4

WKMCD

iTrader: (2)

Sweet car...

BTW: Looks like you built it with the steering wheel on the wrong side.

chris-m

lol! no its you guys you are all weird!

soundengineer

iTrader: (16)

I personally dont like to use synthetic oil at all...
especially not untill you are 100% sure you are fully broken in and all rings are fully seated..
granted you are not putzing about like the average person with your car...
but I would wait a while till you put in synthetic...several hundred more miles in my opinion...

as far as oil grade... I would stick with what the engine builder tells you to.
depending on tolerances, you may need to stick with that 15-50.

blazer427X3

I wish I could help with your question, sorry.

I just wanted to post and compliment you on your car ... it looks great and i bet its loads of fun on the track.

LS6427

iTrader: (2)

Synthetic oils are a waste of time and money for most street/strip type builds, meaning your every day 383-454 type build for a street car. They are nothing special and are just an every day V8 build.
Non-synthetic oil protects normal engines just as good if not better than synthetics do.....synthetics are all marketing hype.

BUT....you have a purpose built race engine.......I would do exactly what your builder tells you to do, who knows what tolerances your engine was built to.

.

ls1 1990 VN

Stick with the mineral for at least 1000mls, in a street car i would go to at least 5000mls

chris-m

thanks for replies. i might stick with the mineral then a bit longer. oil temps are actually a bit low, with 15-50. the tolerances etc arent anything special, it was just a decent spec bottom end build (stock crank, carillo rods , forged pistons).
the car is a hoot tho!

Always2Slow

iTrader: (8)

Your not going to hurt the motor by running mineral oil keep running the 15. 50 for a while at least 1 to 2k miles

WKMCD

iTrader: (2)

On a road course the synthetic will give you 20-30 degrees more protection that dino oil..

Just something to take into consideration.

chris-m

fair play, might stick as i am then. oil temps generally run about 90c, my thoughts next were to run a mineral 10-40w rather than 15w-50. the engine has been properly thrashed on track to the redline on the recent trackdays with no ill effect, but the oil temps were still fine. I can get good quality mineral oil in 10-40 or 15-50 from the same supplier without any probs.

our local costco had castrol magnatec semi synthetic on sale 10w-40 on a good offer with 2 gallons for £28 all in, which is what i normally pay for the mineral oil, i was tempted to run that this season, but might pass on it for now.

i think i will probably stick with a good mineral 10w-40 and do another season on this grade oil. i usually change it twice a season as i only do about 6 events per year anyway.

ls1 1990 VN

Mineral oil is not going to hurt your engine, but full synthetic will glaze your bores if not well bed in & you use it to soon.

chris-m

yea aware of the glazing issue, i am just trying to judge if say my 300miles of very hard track use after a proper bedding in procedure will be enough to move onto a semi or full synth,would that equate to 1-2k on road miles?

i did a proper heat cycle bed in,then with proper hard throttle after about 50miles of driving, as per the builders instructions, its not been allowed any risk of glazing. i just dont have enough experience of this to judge if this is enough thats all. mineral wont hurt it tho as people have said.

ls1 1990 VN

If your indoubt mate, just stick with the mineral, add a few more miles before changing over.

jalper

iTrader: (9)

I have talked to Redline Oil and they had a lot of good advice, I do agree with the comment on the clearances, but Redline oil strongly felt on a oil temp gauge to dial in the oil