i have heard people ssay that there running a 5mil long rod crank does that mean its a 5mil stroker
is there such thing as a 5 mil blaster ?
- Thread starter blaster hybrid
- Start date
No it means the rod lenth is 5mil longer than stock. This raises the piston and decreases the rods angle at half stroke to reduce wear. Mechanical advantage as some would say. This is my take on it...
Surfrjag is right.
The blaster rod is 110mm long center to center. The banshee rod is 115mm long center to center. The 5 mm extra long rod gives the piston a little more mechanical advantage over the crankshaft during the combustion phase of the downward stroke and decreases rod angles.
A 4mil stroker crank is the longest a standard case can hold. Anything more than 4mil is a custom case (not just a stock case trenched to accept a longer throw)
The blaster rod is 110mm long center to center. The banshee rod is 115mm long center to center. The 5 mm extra long rod gives the piston a little more mechanical advantage over the crankshaft during the combustion phase of the downward stroke and decreases rod angles.
A 4mil stroker crank is the longest a standard case can hold. Anything more than 4mil is a custom case (not just a stock case trenched to accept a longer throw)
spacer plate, yes. I had a 4 mil long rod (RD400 rod) with a 4 mil spacer plate and double gaskets but a totally stock top end. The long rod increases the mechanical advantage on the crank but doesn't necessarily have anything to do with the cylinder and head.
You wouldn't need to do a head mod unless you have a 4mil stroker crank with the 5 mil long rod.
You wouldn't need to do a head mod unless you have a 4mil stroker crank with the 5 mil long rod.
The 115mm rod comes from the rd400,the banshee rods are the same as the blaster rod. Haven't heard of anyone doing a 5mm stroker crank but I have done a few 6mm strokers before. The longer rod will reduce the rod angle and change the dwell of the piston at TDC.it will also allow you to run slightly taller ports but still keep the same port durations,sometimes this is an advantage.To run a longer rod you will have to buy a spacer plate and 2 gaaskets.Cometic sells a spacer specific for the long rod conversion
OK, I had a 4 mm thick spacer plate and a 20mm OD wrist pin bearing.
I looked it up a LONG time ago and I thought the RD400 was 114mm long with the 20mm OD wrist pin. Apparently, I was mistaken and now am not sure what the 4mm longer rod came out of!
You just read more and more every day. How come this sort of stuff isnt like general public knowledge? There should be info on all the nifty fun things you can do to your engine.
I don't have any photos of the cases,the last one I did was back in 2005.I will say this,its more work then its worth to do it right.I don't do them anymore because they are just to much work and most people rather not put that much money into it so I quit doing them.
You actually have to build new sections of case material to get that much clearance right?
I imagine it would be a lot of work considering the case screws which are limited on how far they can be moved out before THEY'RE outside the the case too....
I imagine it would be a lot of work considering the case screws which are limited on how far they can be moved out before THEY'RE outside the the case too....
Ok, I was incorrect about the source of the 5 mil long rod (and cannot remember for the life of me what the 4 mil long rod came out of) but my suspicions about a longer than 4 mil stroker crank are scaringly true...
Sounds like a DRAG ONLY modification.
Sounds like a DRAG ONLY modification.
your right,the biggest problem you'll see with a 6mil crank is the port durations are already pretty radical just by installing the crank.there's no room at all to lower the cyl. Anymore because the top ring is very close to the deck already.
for example let's say we have a stock cylinder with a stock crank then we put let's say a 4mil crank into the mix,without even touching the ports and no spacer the port durations go up off the bat,then if you throw in the spacer with it your just compounding the problem,imo its always best to ditch the spacer because you can always raise the ports if needed.
for example let's say we have a stock cylinder with a stock crank then we put let's say a 4mil crank into the mix,without even touching the ports and no spacer the port durations go up off the bat,then if you throw in the spacer with it your just compounding the problem,imo its always best to ditch the spacer because you can always raise the ports if needed.
