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concerning the Book of Secrets,
listed below is what Mike and I discussed over the bit of time while we were together at the flow bench.
* Seat Angles: Mike used a 30 degree angle on the intake and a 45 on the exhaust. We talked at length on how a 30 degree valve seat 'opens' earlier but gives up flow at the the higher llifts. Mike said that with a head that is flow limited like the slant he was a believer in getting the flow started as early as possible. Mike put preference in maximizing low and mid flow volume at the expense of the max flow at full lift. He commented that the cylinder sees full lift once, but the mid and low valve opening occur twice on every cycle.
* Where to work in the port cavity: do the work in the port bowl, leave the port arms alone, except to clean out casting flash, obstructions. Mike will reduce the height of the valve guide boss in the bowl. More so on race heads, less on street heads. As expected the short side radius gets attention.
* Intake to exhaust flow balance: Mike agrees the standard 75 to 80 percent is a good target. Make said generally there is more time invested in the intake than the exhaust.
* Valves: Mike uses Chevy 2.02 intakes cut to a 1.76 head diameter and the matching 1.60 exhausts cut to 1.46 diameter. Intake valves get a back cut. The valves have 11/32 stem diameter. the stem length is .110 longer than the stock slant valve stem. Mike said he did not make valve train geometry adjustments due to the longer stems. He said he liked the Chevy valves as they are produced in such great numbers they are relatively cheap. I found a set of 8 intakes and 8 exhausts new on Amazon from Elgin for 88.64 with free shipping.
* Valve springs: beehive matched to the cam for pressures.
* Valve seals: on race engines, seal on the intake stem, to prevent sucking in oil, no seal on the exhaust stems.
* Guides: bronze
* Rod and Main Clearances: .0015 to .002,,, Mike said he runs the thinner oil, going to 0 w 30 when he needs to go really fast, said it really frees up the motor. Also said he seldom spun the motor above 6200 RPM. He said he typically used Clevite 77 bearings, but he is sure he used other bearings with out issue. Said he used a stock high volume pump,(I believe he was speaking of a pump that was ported to increase flow) but never a high pressure spring or shimmed the spring to push up the pressure. Said that he did not use a rod bolt stretch gauge or torque and angle. He said for critical fastners he folllowed the bolt or engine spec for torque,
would bring up the torque in several steps, let the tight joint sit overnight, loosen the fastner, then again over several steps again bring the bolt up to the torque spec. He said he used ARP bolt lube.
Timing chain sets: Mike said his preference was the crank sets with the multi key ways. Mike felt it was just easier to deal with.
Mike J was very successful for many reasons,, more than just the head porting, more than the engine building, looking at the Buzzin Half Duzzin,,, the front and rear suspension were reworked, rack and pinion steering, delaybox and other electronics, air shifter, and on and on and on, and he had an on staff mechanical guy to help out and Mike raced the car on a regular basis. Touch all he bases and you get a home run.
He also said the slant six drag scene was a lot of fun, but he is totally done with that and moving on to other adventures.
_________________ Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8
Last edited by DadTruck on Tue Mar 27, 2018 2:20 pm, edited 3 times in total.
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