So the recommended threshold for a block girdle is around 600hp right? So what if you use the billet main caps, does this extend the safe zone a little? Lets say on a 600-625hp motor, If I use the billet caps would I be relatively safe or should I still girdle? Thanks
i would use the girdle the weakness of the bottom end is not in the caps its in the main webbing of the block.In high performance applications the extra force can crack the webbing of the block ...mike
Yeah, I agree. I've never broken a cap, but I've broken the webbing at least once. And that was WITH a girdle. Scotty Guadagno took the girdle off my block to inspect the mains, and a piece of the block webbing fell out! Of course, I DO tend to stress these things a little! :laugh:
So if I girdle the 625hp motor are the billet caps necessary? What about hard block? Should I partially pour or can I get away with not using it? This motor is also going to see some street duty and I heard about oil temp problems on the street when you hard block.
Not to take over the thread, but how about a good internal balance job, half fill of hard block, and pinned billet caps with studs? Would that hold up at 650 hp? ________ DAIHATSU MIRA HISTORY
A real light reciprocating assembly will allow going over 600hp ,I've got over 900 passes on Scat's motor now with some light weight components w/o girdle or hardblock.I've seen guys approach 650hp with the caps pinned and light stuff. gary
How light is light? What pistons, rods, etc. would make a good light weight assembly? When I researched this, it seems like you have to have flat top pistons to get the really light stuff, which means a race gas motor. What about those guys that want a light assembly pump gas motor? The wiseco dished pistons come in at around 680 grams. Stock rods are (if I remember right) around 700 grams. I think TA said their sportsman replacement rods are stock weight, which I guess isn't too bad, but it's not all that light, in my opinion. Is there a better dished piston alternative that is lighter? Does anyone know of a good source of aluminum rods, and how light do they come in at? ________ Gay Doctor
light is light Joe I use venolia pistons ,they come in at 649 grams with pins,also bill miller aluminum rods,which weigh598 grams.Even though the pistons are flat top I'm only running 11 to 1 compression in a race motor with a 64cc head.Before I installed the pistons I had them dished .030".If you ran a 68cc head and more deck height you'd be around 10.4 to 1,very streetable.We also worked the counter weights some on the crank to reduce its weight and knife edge,don't know how much though we never weighed it.doubt if it was more than 8ounces. gary
bottom end Hey all, Another suggestion would be to use billet caps and a block halo, and also theres another girdle that connects all the mains together just a thought ..... :TU:
I thought the block halo was an addition to the block girdle? The TA halo goes on the girdle doesn't it? please enlighten me
bottom end I Guess that i was thinking of somthing else but ive seen an outer block reinforcement but dont know if it was for a buick or not sorry for the mix up...
Todd, Since Gary "Old Man" Paine put that engine with 900 passes together.... (Gary... how long ago was that?? )... REAL race parts have improved greatly. The lighter the part the better. I am sure at the time 649 grams was very light. Attached is a picture of my piston and wrist pin on a gram scale. My connecting rods are 547 grams with a total bob weight of 1674 grams.
Wow John thats light,but wheres the "skirt".man that must be a long rod.my bob weight was just over 1800gm.And yeah,that motor was put together when you were still in high school,still trying to get to 3rd base. :laugh: it was actually in "Thumper" in the 80's,man I'm gettin old.Its still goin strong with the iron stage2's. Maybe I should upgrade to the new technology and instead of shifting at 6000 :3gears: go to 6500,pick up a tenth or two. gary
