With the bolts needing to be drilled for the oil passages this provides the scenario of oil flow restriction.
Does anyone have any coments on this affecting oil flow to the head and cams at lower revs and startup? It’s a benefit in terms of leaving more oil in the sump but is it detrimental to lower levels of flow to the head?
Will be using a wet sump with high pressure / high capacity pump.
Planning on drilling the bolts as per Rohan’s advice at 4mm diameter for both the hole up the bolt and the hole at a right angle to meet this.
The oil flow to the head is largely dictated by the cam bearing clearances and the oil holes in the cam itself. The long bolt bolt has limited impact on the oil flow compared to these provided it is done right
Any thoughts on going smaller on the holes (ie 3mm) with a view to keeping more material in the botls?
How did you arrive at the 4mm? Is that the thinking of Dave Bean and Col Croucher?
I’m thinking of the cylinder block to head feed gallery at the front of the block that can me modified to take a restirctor to control flow up to the head - these are usually 0.090" - 0.120" diameter.
Therefore a 0.120" / 3mm hole in each of the bolts would have less effect on flow than a block restrictor would in comparison.