Originally Posted by
Richard Kaye
My 9.35:1 pistons have arrived (they are very shiny), the rings are already installed on the pistons. I have also ordered a die grinder and cartridge sanding rolls, some 200mm long feeler gauges to measure the piston clearance and bought an air compressor. I will have a go at cleaning up all the casting marks in the ports myself.
I am not going to remove the motor until I have all the bits I have ordered, but need to get a valve spring removal tool. The one I am looking at says its suitable for valve spring retainers of 25mm and 30mm diameter. So, has anyone got a head with springs in or a retainer to measure the diameter of it for me?
Hopefully all the parts will be here in the next week or so, then I can remove the motor and get started on it. It will be interesting to see if cleaning up the ports and the new high compression pistons make much of a difference.
G`day 31.7mm , 10 bolt heads have larger ports the valves are the same size 3.5 and 3.9 as far as your 88 is concerned it is only the early 3.5s that have smaller valves, 3.9 tin is thicker than 3.5 tin , 3.9 10 bolt , head bolts are torque to yield best practice not to reuse , 3.9 14 bolt heads use same as 3.5 and are reusable , your 88 3.5 bolts can be used .
The exhaust valves in your 3.5 should have the same stem wasting as your 3.9 but they will be flat across the valve face so less ccs , 3.9 will have a concave . I have these valves from a 3.5 in 10 bolt heads on a crossbolt 4.0 so know they work the engine is in an 85 using v belts .
The heads have measurin points on each corner that tell what std is and if they have been machined .
I used to use tin gaskets but found i had to have the heads off more often than i liked though it was higher comp by removing material from the head faces , enough that the inlet wouldn`t go on std but ther is a formula to work out how much to take off the inlet face on the heads so a std inlet fits and if you match port the heads i`d suggest you also do the inlet manifold . I d also suggest you look into setting the timing using a vacuum gauge .
Cheers
PLR or peter r elsewhere
BA KA MA RRC L322 TD6 R1200GS
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