4G63 evo 8 crank vs dsm 7bolt crank

[Alex7747]

DSM Graveyard charges $275

thanks

 

[delta448]

I can't really say what I'd like to about that, but you may want to look at the vendor reviews.

Personally, I've always wanted to try a butcher crank from FFWD.

 

[twicks69]

Just watch your power levels and engine load (rpm & boost levels) with the Butcher crank. It was great below 650awhp, but showed its structural weakness at higher power levels as it would jump-rope the main bearings. Just remember, the lighter the crank, the lower inertia it will have resulting in the ability to rev quickly, but it will also produce less torque due to lower inertia when compared to a full weight crank, and you will want a real standalone EMS to control the ISC as it commonly has issues with decel throttle and idle stability. Mine revved out very nicely especially with a twin disk clutch assembly on the GT4088R as it was stable to 8400rpm for 3 years of abuse and daily driving. When I was shifting at 8600-8700rpm and doing HIGH boost (42-52psi) / 650-760awhp, that is where I saw the crank issues occur.

Again, I would only lighten the crank if you are going to stay below the 600-650whp range and keep it within acceptable boost levels and rpm range for the rod ratio. On a 2.3L 100mm crank/standard rod length motor stay at or below 8400rpm on steel rods and you will be fine. If this is a street car, and you are sticking with a single disk clutch, do a full weight crank. If you are going balls-out, lightweight crank with a twin disk gear drive QM clutch on a HP max of 650awhp. Above that you will risk bending the crank like I did, even though I ran it to significantly higher power levels (766awhp/713tq), high rpm (8600-8700rpm), and very high boost levels on a 40r (42-52psi); I would follow my recommendations above to get longevity out of the combination with a nice set of Ross or CP or Wiseco 1400HD pistons, thick-wall tool steel wrist pins with wire locks, Swain coated main and rod bearings (peco-polymoly coating), and coated pistons (goldcoat dome, polymoly skirts) to increase protection from thrust loading and ensuring oiling capacity on either ACL coated bearings or Mitsubishi OEM main and rod bearings on a quality 20w50 high zinc oil.

 

[delta448]

Tim, did you break anything in particular, or what sort of issues did you have that let you know you were starting to get some flex in it? Just for future reference... I don't plan on reaching 650awhp anytime soon.

 

[twicks69]

Tim, did you break anything in particular, or what sort of issues did you have that let you know you were starting to get some flex in it? Just for future reference... I don't plan on reaching 650awhp anytime soon.

I bent my crank around 0.015" out of straight from excessive power for the crank to handle with nearly 10# of weight chopped off of it. It would destroy the crank angle sensor, crank main bearings and would seperate the counterweight on the crank harmonic pulley when it was on its way out. The inner main bearings would be smoked with a good thrust surface and good outer mains and chewed rod bearings from using Clevites the last time which simply couldn't absorb the shockloads from the boost levels.

 

[caged]

I use an evo 8 crank in my evo 2, got it off a guy building a stroker for his 8 for $150. The best bit is the thrusts are always good because the evo 8 is pull clutch and wears the other thrust side.