Need information on improving the oiling system

[Jerry]

Hello to the forum, My name is Jerry and this is my first post on the forum. I want to use the 60 degree GM V6 in an Indy lights engine. (This engine will power an open wheel formula car and will compete in the HSR/SVRA historic formula car series.) The rules of the organization state that a cast iron block must be used as per the original series. The engine will need to turn 7500 (+?) and will be dry sumped. I understand that the V6 has an oiling problem because there are only two galleries that carry oil to the mains, rods and cam. Would opening/ enlarging/drilling the mains in the block, the main caps or adding addiitional external lines improve this system in any way? Appreciate any information and opinions from the forum on how to improve this system and thanks. Jerry

[SappySE107]

Are you restricted to a year? If you can use a 3100 or newer engine, which have 3 galleries instead of 2. Using the 3500 would also give you an oil squirter on the number 5 and 6 pistons for cooling. Those 2 cylinders run the hottest, and you could also tap for 2 more if that is allowed.

[geoffinbc]

Agreed. The 3rd Gen block and up are TRUE priority main oiling. They are the best.

If you cant use it don't worry the non priority main system is very adequate and was used back in the day in midget series. Since you are using dry sump there really is not much you need to do. Chamfer the oil holes in the crank and cross drill the journal supply passages and that's about it. Stock pumps will supply these engines above 7000, with a dry sump you are already way ahead of the game.

[Jerry]

Improving the V6 oiling system

Thanks for the replies to my question on improving the oiling system on the V6. I did a search on the GEN 3 V6 and noticed that it has a stock bore of 3.50". Can this block be safely bored to 4.00"? I wanted to run a 4.00" bore and a 4.00" stroke which would give 5.0 liters. Also would you suggest an "odd fire" or "even fire" crank? (Crank will be 4340 billet.) Thanks for your input. Jerry

[ForcedFirebird]

3900 block can be 4" and has a forged crank, with the better oiling.

[geoffinbc]

Thanks for the replies to my question on improving the oiling system on the V6. I did a search on the GEN 3 V6 and noticed that it has a stock bore of 3.50". Can this block be safely bored to 4.00"? I wanted to run a 4.00" bore and a 4.00" stroke which would give 5.0 liters. Also would you suggest an "odd fire" or "even fire" crank? (Crank will be 4340 billet.) Thanks for your input. Jerry

Your thinking of the wrong engine man. No 60*V6 was ever odd fire. Only the Buick V6 (3.8L) and the Chevy 90*V6 (4.3L) ever had the option of being odd fire since they were derived from a V8 and early engines used a common pin crank which created an un even firing pattern. There are pros and cons when choosing an even or odd fire engine but we wont get into that here.

The 60 Degree V6 was factory built as a V6 and was designed with the cylinders offset enough (for and aft) to accommodate a crank with 6 individual throws and a even firing pattern. The V6 fires every 120* and each bank alternates in the firing pattern. There is no spot in the firing order where 2 cylinders on the same side will fire one after the other like in a V8. The engine was designed with a very easy to remember firing order of 1-2-3-4-5-6.

A 3.4L/3400 Cannot be overbored any more than .040" because these engine are a thin wall casting. However the 3900 and 3500 VVT engines share a 99MM bore which gives you 3.89" I am not certain if the 3900 can be bored to 4.0" but your already pretty close. The stroke is 84mm which again could not be made to reach 4" without a billet crank which I doubt you will be able to find easily. If you know a crank builder then you can obviously get whatever you want. But keep in mind if you go with an insane stroke you are stuck with he stock deck height and may be forced to use really short rods which would also suck.