Engine Build suggestions. Mini d heads, C35 cam, 5.5 H Rods

[jestermab]

I have recently had an engine failure and want to build a new engine. I naively ran Scat Mini D Heads (40x37.5 dual spring) on forged 87 mm Mahle pistons. I used GSC 1.25 rockers and chromoly rods. The ali crankcase was damaged by the lifter on the inlet on the 4th cylinder. The rocker geometry was set perfectly and the engine was very free revving, it would see 6k to 7.5k very very easily. I kept the max RPM to 5500 but it would easily smash past that observed limit if I took my eye of the ball. Eventually the lash caps kept falling of the inlet valves of cylinders #2 and #4 and I found a piece of crank case from around the lifter at piston #4 The current set up was:

Duel relief 1600 case,
Stock cam,
stock crank & rods,
Weber IDF 36 carbs,
Scat Mini D heads 40mmx37.5mm dual springs 85.5 bore (can be machined if need be)
CSP supercomp exhaust,
SCAT oil pump with spin on filter.

I have in stock for a new build:

existing Scat mini d heads, CSP exhaust,
New Bugpack 5.5 H-beam rods,
New equaliser pulley,
New Scat C35 cam,
used weber IDF 40 carbs... but in need of an overhaul
new Bugpack titanium valve retainers,
New HD single valve springs,
new Chromoly rods, and new Bugpack HD ali rods -cut to size,
30mm oil pump 3-bolt cam type,


Can people make any suggestions ? Thanks

[Marktt]

I think what you have described I have just encountered and have yet to determine the cause, thinking, valve train components, cam. My failure was immediate, 2 lash caps, on intake, same side motor, one fell to the cover and the other was jammed halfway out and adding some major width to the subject valve/rocker contact. Other side of motor one intake, the push rod was half out of the rocker socket, jammed as well. Being an old post hopefully your monitoring it, others may find my input in a search as I found yours.