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Saturday, September 19, 2020

Doug's Domain

Doug Vetter, ATP/CFI

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Wednesday, August 9, 2017

Parts Delivered to Machine Shop

Today I took the block off the stand for the first time in a week and lowered it down onto a pallet sitting in the back of the pickup. I prepared a list of requested services and an inventory list showing all the parts I provided and took it with me on the short drive to the machinist's shop. Upon arrival I spoke with the owner, Rich, for a good half hour in detail about the project. I explained the reasons for the rebuild and my goals.

The first thing we spoke about was cleaning the block. As it turns out Rich no longer does cleaning in his shop because of the headaches of dealing with the EPA and the state of New Jersey DEP. Apparently they track every drop of the chemicals used to strip blocks and require reams of paperwork to prove that the used chemicals are is disposed of legally. Combined with the costs to dispose of the fluids (hundreds of dollars per barrel) and the costs associated with keeping the tanks hot it just wasn't worth the expense. My block and other components will therefore be shipped out to another local company that specializes in cleaning.

When I explained my need to have the sides and rear of the block down to bare metal for painting he said that in order to achieve that the cleaning company will most likely have to shot blast the block to some degree. When I proposed putting the block through a parts washer and then sealing up the block and sand blasting the sides he quickly shook his head, smiled knowingly, and said "nooooo, that's a very bad idea...media gets EVERYWHERE no matter how well you try to keep it out". He strongly advised I avoid that and simply let the professionals clean the block so it is absolutely spotless when it is returned to me for assembly. To reduce the potential for flash rust I suggested that he coat it with WD40 or some other light oil and he agreed that is the best thing to do.

Without so much as glancing at the block he pointed out that the plugs on the front and back of the block will have to be removed. As they are press fit he said the first plug will have to be drilled, threaded, and then pulled with a slide hammer. The second plug would likely be pressed out by inserting a drift through the block. I agreed to this process and told him I would come back with new plugs for him to install.

I then turned the topic of conversation to the piston to cylinder clearance, showed Rich the build sheet along with the recommended clearance specs, and told him that my measurements of the new pistons revealed about a 3.1 thou clearance with an 84.5mm bore. He said that the minimum clearances are exactly that -- minimums, and are written all over the documentation to effectively absolve the piston manufacturer of responsibility. I knew he had been down this road before when he then recited the warning I read on the JE docs which was in effect "the engine builder assumes full responsibility...bla..bla..bla." Based on the numbers I provided he said JE wants us to run 3 thou clearance, and that is not unrealistic for 4032 pistons. I summarized the requirements by saying that Top End Performance (the JE distributor) told me to tell him to bore for 84.5mm and he agreed that was the safest course of action.

We then spoke about the cylinder boring and honing process and I reiterated that I want a plateau finish in order to seat the rings as quickly as practical. He then took me over to his Sunnen machine and showed me a very large array of stones and the plateau brushes he would use to achieve the final finish. While standing alongside this rather large piece of equipment I asked him about the crosshatch angle he would provide. He said the typical crosshatch angle is in the 40-42 degree range. I then asked "What is the difference between, say, a 30 degree and a 40 degree angle?" He said that crosshatch is responsible for causing the rings to rotate around the piston and the precise angle is the result of a formula that takes into account, among other things, the stroke of the piston. For a given set of conditions, the higher the crosshatch angle dictates how fast the rings will rotate. Of course, some degree of ring rotation is required for even wear in the cylinders. If the rings were static, the ring gap would wear a profile into the cylinder wall.

Rich seemed happy to see that I brought a torque plate and said that he likes to use them when provided. When I showed him the plate and the standoffs I wondered aloud whether he would need some washers to fit under the head bolts and he said yes, so I agreed to bring him the washers from my head.

With our conversation wrapped up we unloaded the parts into his shop and I headed back to the garage. I'm expecting delivery of the parts in 5-8 business days, which is fine by me as I have a ton of other work to do on the body of the vehicle to prep for the installation. Which reminds me...I need to get back to work.

Next Up

I'll start work on the chassis tomorrow. The first task is replacing the hood release cables and receptacles. Once that's done I'm planning to spend a few hours cleaning up the engine bay in prep for some rust remediation. More on that later.