synthetic or no?

[bansheemorphine]

i have a 99 440ex that was just rebuild i have a stage 2 hot cam 89 mm piston port and polish degree key and hd valve spings the person who built my motor told me not to run synthetic oil i want to know why i always thought synthetic was better??

[Colby@C&DRacing]

don't run a synthetic oil for break in but after that your are better off running a synthetic.

[below100hz]

ive always used synthetic in my 400ex but when i did my 426 and cam i had to run petroleum based oil, sythetic wont offer enough for the break in, and besides you are gonna have to change the oil after the first 20 or 30 mins because that cam is gonna lose alot of metal, id rather spend less than $2 a quart for oil that i will only have for a short time than spend the $7 for synthetic. im still breaking mine but the next time i change it it will have synthetic..... buy a few oil filters