7A stroker project.

[Rocco]

Dry sump 9000 stock 8000.

ok ok , it is a madness anyway

[caterpillar]

Im running an 8000rpm redline on 95.5 stroke with 1.66 rod ratio. Stuck to 8000 so I could stay with hydraulic lifters and stock oil pump.
if I dry sump it and solid lifter it, it will sit at 9000rpm with 2bar of boost and no issues as I kept thebpiston diameter to 82mm and fitted ductile liners giving improved bore elasticity.

Alternativelly could change rod ratio to 1.75 and rev to 10,000 but the extra length of the rods will make the engine feel less responsive.

the recipe of the engine and how long have you had this 8krpm limit; effect in engine

[JP]

No bore deflection or bearing wear after 2000+miles of v hard road use. Compared to cast grey that starts to show 1/2-1thou of wear on thrust side on lower half of bore with less than 1000miles.
Ductile iron has tensile strength 4x of cast grey block.
Giving much greater ability to return to original shape.

All aluminium drag race engines run ductile liners. All pro mod engines do etc.... very effective way of exerting extreme pressures whilst retaining reliability.

[Jim_Coupe]

77,4 crank ? Where does that come from ?

[caterpillar]

the old 1900, 2000ccm 5pot...vw 32b or similar

[Jim_Coupe]

Im running an 8000rpm redline on 95.5 stroke with 1.66 rod ratio. Stuck to 8000 so I could stay with hydraulic lifters and stock oil pump.
if I dry sump it and solid lifter it, it will sit at 9000rpm with 2bar of boost and no issues as I kept thebpiston diameter to 82mm and fitted ductile liners giving improved bore elasticity.

Alternativelly could change rod ratio to 1.75 and rev to 10,000 but the extra length of the rods will make the engine feel less responsive.

wow you runn 8000.. but not with small deck right ? U use diesel block ?

I have 95.5 on 220 deck and 83mm bore.. I took engine apart for inspection after last season.. coulndt see anyting on the cylinderwalls yet and so on..

[Rocco]

the old 1900, 2000ccm 5pot...vw 32b or similar

NM engine crankshaft true?

do you know a shop what does dry sump sistems for our engines? i am sure in scandinavia there are some

[JP]

wow you runn 8000.. but not with small deck right ? U use diesel block ?

I have 95.5 on 220 deck and 83mm bore.. I took engine apart for inspection after last season.. coulndt see anyting on the cylinderwalls yet and so on..

Diesel block yes to maintain stock rod ratio. Brave person to run 95.5 stroke on 220 block. Very lifely revy engine due to the fast pistons speeds but a lot of pressure at high rpm.

[Jim_Coupe]

yep.. im living on the edge hehe...
but the engine is just amazing.. I dunno what it is but the Torque is just totaly not from this planet. something happens when you runn 220deck and 95.5 crank.

I have the golden Rod angle for torque but not reliability in the long run.. its gonna be intressting to se how it hold togheter.. i use coated Volvo S60R MAHLE pistons.. state of the art **** )


But it would have been cool to build an engine like this but Normally aspirated !!
2.7L NA that would be nasty.. Im thinking nissan 200 pistons (83mm) and stock rods on a 95.5..

hear the sound of 2.7L 7A + E85 + VEMS ohh nasty stuff.



.

[JP]

Its all to do with pistons speed. Closer you get to 1.5 rod ratio the more torque it will produce low down with correct turbo setup the closer you get to 1.75 the better sustained rpm you can have.
The idea is choose rpm band for desired turbo and projected hp and build engine with correct piston speed for the application.
Similar with cam lift and headflow everything needs to work 100% with each other if correct goals are to be achieved be it na or fi.

[Jim_Coupe]

hehe yep.. im with you... but some of us nut cases just build something and after that we realize.. aahaaa..