Looking to build a 420 Longrod engine

[cyp65]

SO I built a 370 longrod engine to rip around the trails and siltbanks here in NEPA and now Im looking to up the displacement. Besides the usual Vito's junk 404 kit, does anyone know any other options than that and the Trinity 420 kit.

 

Thanks, I'm new here so anything is a big help.

[Leadfoot350]

put a bigger crank in it rather than the big bore kit. I big bore kit uses biger sleaves which make the transfers smaller and it cant flow anything. Get atleast a +4 crank, nice porting, carbs, pipes,and anything else you can think of.

[Indubitably]

10mil cheetah setup by dan hull and some lectrons thats big hp's

[cyp65]

Well, Im already at the +4 or +5 with the longrod crank from wiseco. The thing is that im at the end of the sizing for the matching pistons and when I need to bore it out, I'm going to have to resleeve and instead of going back to stock I would like to get more displacement. The option of Vito's 404 kit doesnt work for me because I dont want to run a spacer plate with the longrod crank. I mean this thing still has to stay trail rideable so basically more power, but spread out over the band.

[SyNtAxx]

Hello,

 

 

Correct me if I'm wrong.....but a long rod crank is indeed different than a stroker crank ?

 

Adding a long rod crank just releives tension on the piston...and the stroker increases overall piston travel ...Yes ?

[jinx44]

Hello,

 

 

Correct me if I'm wrong.....but a long rod crank is indeed different than a stroker crank ?

 

Adding a long rod crank just releives tension on the piston...and the stroker increases overall piston travel ...Yes ?

This is correct. I hate people that don't know what they are talking about. A guy once argued with me that he had a 9mm stroker. +4 and 5mm longrod.

[liszewski_88]

Essentially what a long rod does is lower the angle of the rod and piston. It relives the stress of the wrist pin. It moves the wrist pin higher on the piston and more towards the center on the crank. Not for sure about the crank part though. What a stroker crank does is exactly what it says it does, it strokes. For a stroker crank you have to get a plate. 4mm stroker would require a 2mm plate.My question is though so u have to put a gasket inbetween the case and plate, then another above the plate and below the jug?

[roosthrower]

I'd say ditch the plate and get the head cut to work with the extra stroke. I'd run two gaskets though with a plate.

[FasterTHENyou]

there is no reason to run a plate for a 4mm. Hell i can build a 7 or a 10mm stock cyl motor without a spacer plate

[racer]

Essentially what a long rod does is lower the angle of the rod and piston. It relives the stress of the wrist pin. It moves the wrist pin higher on the piston and more towards the center on the crank. Not for sure about the crank part though. What a stroker crank does is exactly what it says it does, it strokes. For a stroker crank you have to get a plate. 4mm stroker would require a 2mm plate.My question is though so u have to put a gasket inbetween the case and plate, then another above the plate and below the jug?

finally, someone understands. cyp65, what kinda cash are you lookin to drop? a 535 cheetah would be nice if youve got the cheese.

[Oilsmoke]

TDR Power valve Setup. I would go with the 480 ANd your Crank to save 5 bills.

 

Oh and I run a .080 spacer plate with no gaskets and never had a problem And I can swap domes all Damm day if needed. Pro & cons I quess.

[cyp65]

Most likely when this engine wears out I'm just gunna step up to a new set of sleeves and start running blaster pistons and new domes cut for them. I dont have the money right now to change the crank and get a set of powervalve cylinders.

[rebelbanshee2]

sounds like your still doing the long rod the old school way. When you re-sleave dont put blaster pistons in. Get the wiseco 795 series pistons they are offset for the LR so you can start at stock bore.