supercharged111
Member
I have a set of SLP triple pipes about to go on, wondering if a thinned head gasket pairs any worse with them vs a stock single pipe? On the tech page it mentions not going with a single layer for triple pipes, rather the 2 thin layers. When you stop and think about it, there will be more air being crammed into the cylinders without the ignition timing being changed to account for that. I guess the only way to know for sure is to read the plugs? When the trails are straight and smooth the throttle tends to get parked on the bar, so that's what I need to tune for.
Going from a triple head gasket to a single layer is like shaving the head .020".
A reduction of .020" clearance brings the squish band clearance down to @ .055" and increases static cranking pressure by @ 20lbs and obviously increases the compression ratio of the engine.
For extended WFO riding a higher compression ratio requires very good fuel and fussy jetting.
Reducing the squish by .020" works good when the engine is also ported and running triple pipes.
Unless you are going to also port the engine I would stick with a two layer gasket and premium + fuel and conservative jetting as the hp difference would be minimal anyway.
A reduction of .020" clearance brings the squish band clearance down to @ .055" and increases static cranking pressure by @ 20lbs and obviously increases the compression ratio of the engine.
For extended WFO riding a higher compression ratio requires very good fuel and fussy jetting.
Reducing the squish by .020" works good when the engine is also ported and running triple pipes.
Unless you are going to also port the engine I would stick with a two layer gasket and premium + fuel and conservative jetting as the hp difference would be minimal anyway.
supercharged111
Member
How does porting affect the engine's needs for quench height? Not doubting you, just curious.
When you port the engine the exhaust port is normally raised a few mm. By raising the exhaust port you decrease the corrected compression ratio...squeeze from closed exhaust port.
You could do this setup if you mix in some octane boost or race gas. Otherwise follow Bob's advice.
I run 91 octane with triple pipes. I layer head gasket. Between my buddies and I, we have around 5 sleds with that setup.
Never had problems yet.
Never had problems yet.
If your nervous, throw a splash of octane booster in the fuel.
supercharged111
Member
Not sure if I should be nervous? I've run it that way single pipe for may years. Was just wondering if triple pipes in and of themselves changed the pre-ignition tolerance. Sounds like porting changes the dynamic compression ratio so yeah, definite increase in knock margin there.
One of the good things about the SLP pipes is they don't have very restrictive stingers/silencer so they are more forgiving then some pipes that were available for the Red Head triples.
I have many 1000s of miles on Bender piped red head triples, between my son's and my previous sleds, and they work great but ours were ported and we never held them WFO for extended lengths of times.
One of my all time favorite sled combos.
I have many 1000s of miles on Bender piped red head triples, between my son's and my previous sleds, and they work great but ours were ported and we never held them WFO for extended lengths of times.
One of my all time favorite sled combos.