power difference

if you build two motor exactly the same and one is bored .060 and the other is bored .030 will there be a power difference????? how much?? on a stock stroke 460

about .030s worth

Lets go on the assumption that you have 1 hp per cu. you would have 466.2 hp with a 30 over and 472.59 on a 60 over.

Curt wrote:Lets go on the assumption that you have 1 hp per cu. you would have 466.2 hp with a 30 over and 472.59 on a 60 over.

thats a fair way to awnser his question for sure. I can add that i have seen more then one pair of engines same everything, cam, bore,stroke, make 25 or 30 more then the other

The bigger bore could help to un-shroud the intake valve a little, and if your going for every last hp that could make a small difference.

res0rli9 wrote:about .030s worth

You ain't right................

I'm building a mud racing engine... and it goes 200 ft about 20 passes a year... and i'm trying to get all the power as possible... i have a lot of rules.. i also have to run Iron factory heads... and pull 15 in vacuum at 900 rpm.. so any little trick i can pull out of this motor i am going too...thanks

Could you post all of the rules, it would make it easier to help decipher the tricks needed. You can do a lightweight knife edged crank, light weight pistons, gapless rings, etc. The big deals are building with proper tolerances everywhere and proper matching of components to optimize power where you need it.

schmitty, i'll just call you some time this week or weekend....

bigunitmudracing wrote:schmitty, i'll just call you some time this week or weekend....

unless u don't want to i'd like to see the rules also.eric

3. Headers allowed with max 1 7/8 size tubes.

4. Mufflers must be bell shape and glass packs allowed, no cutting of mufflers.

5. Any external modification allowed: any single carbureted intake, carburetor, and ignition.

6. Factory fuel injection allowed.

7. Any factory production (truck, van or suv) heads are allowed. No after market performance heads.

8. Engine block and lower end must be stock for year, make, and model. Can check by 8th V.I.N. number.

9. No high performance engines.

10. No internal engine mods, aka timing gears, if found will have to bump up a class.

11. Engine may have maximum overbore of .060. Piston and piston height to be stock configuration, Deck height to piston must remain stock.

12. Engine must remain in stock position.

13. Engine must pull 15" of vacuum at 900 RPM. Can and will be checked at random. If fail bump a class.

14. No porting, polishing, or grinding of any kind on heads. Maximum valve diameter must be stock according to casting numbers on stock heads.

15. Pistons to be flat top or dish according to year, model, and make. No domed pistons.

16. Any radiator may be used in stock position only. No cutting of hoods.

17. Converters and clutches must be stock for vehicle.

18. Gas only, no nitrous or alcohol.

There are rules here i will more be pushing to the edge!!!! call it what you want.... there are trucks that beat me by 3 seconds a pass, dont tell me they dont push it too.... I know for sure trucks are running converters and centerforce clutches and they dont do anything about it.....

BOSS 429 wrote:

Curt wrote:Lets go on the assumption that you have 1 hp per cu. you would have 466.2 hp with a 30 over and 472.59 on a 60 over.

thats a fair way to awnser his question for sure. I can add that i have seen more then one pair of engines same everything, cam, bore,stroke, make 25 or 30 more then the other

To many variables to answer any other way.

I can run a flat top piston, i can run any ford iron head, and 110 turbo blue gas comes out of a pump!!

Pretty stringent rules, but there is plenty there to work with. I'm with Dave, DOOE-R heads, flat tops, and a well thought out rotating assembly and cam, induction.