Don Terrill’s Speed-Talk

Can we now just read what the rod is for?

ptuomov wrote: ↑Sat Oct 07, 2017 5:05 pm Can we now just read what the rod is for?

David Vizard wrote: ↑Sat Oct 07, 2017 1:02 pm Most responses were no where near the right answer and some were very critical of me posting in the first place.

DV

Nobody, and I mean NOBODY is critical of you posting in the first place. I think EVERYBODY here wants to here your thoughts on engines, and share information and ideas with you. It's just the "show" and the "sell" that bothers people, including me. We've seen it over and over.

JMO,

paulie

So after the uproar this simple post produced here is the answer to how this all goes together.

First the block;- This had new thick wall liners installed in every cylinder. Prior to boring to size the blocks water jacket was filled with concrete.

The bores were then prepped as accuratly as possible to the 5 different bore sizes than I most often use. Together with the long rods this is how the block will be used.

Firstly the pistons have the crown machined with a hole that will accommodate the rod coming through. The piston is then mounted on the rod upside down. With the wrist pin above the top of the deck it can easily be removed to allow the piston to be removed from the top of the block. The reason for this is so I can quickly access the rings and replace them as required. The rotating assembly will be turned over at about 200 rpm max (I did say as a clue that the rods would last almost for ever even though they are welded) The purpose of this 'fixture' is as a ring break-in and polishing machine.

Why go to all this trouble? Because my previous method was too time consuming and time is the one thing I am short of.

Using a proprietory oil blend the rings will not only be polished but also the surfaces will receive a very thin layer (about 100th of a thou) of hard ceramic coating.

Try this little exercise next time you build a short block. After it is all together get a long breaker bar and turn the short block over about a half dozen time as fast as you can. Now take a sniff of the block.The chances are you will smell burnt oil caused by the new rings micro welding to the bore. To produce that smell temperatures need to go significantly over 400 F. Just give this a thought for a moment. That micro welding goes on during break-in and only stops (or nearly so) after a fully developed inter-component surface and oil film has been generated. In essence the rings do the final machining on the bores.

Why am I going to all this trouble? easy answer I can't afford to reduce piston assemble to bore friction the way it is done on F1 engines so I have had to come up with my own affordable solution.

Not only does this ring break-in fixture polish and plate the rings but also can be used to measure the the turning torque as the block is supported at a level just above it's longitudinal axis. A torque arm to the frame holding the block allows for load cell output to register the turning torque.

So how well does it work? With the bores prepped in the manner I use which is a double deal (cross hatch applied first and then a very fine vertical platue finish on top) it works very well. In a worst case scenario it cuts friction in half and in a best case scenario it cuts it by over 75%.

For example the initial turning torque my 383 Chevy short block builds usually runs around 18-20 lbs-ft when done in a conventional fashion. Prepping them as described here the turning torque is typically 5-6 lbs-ft. As for wear, when used with a top quality oil, the measured wear is extremely low to non-existent. My Cup car Dodge engine had 1500 race miles on it and exhibited no measurable wear in rings or bores. In fact it looked like it had never been run.

Just a further note here. The ceramic plating on the rings won't micro-weld to the bore material.
DV

Does the long rod change the rotational torque needed to spin compared to a short rod? I bet it does. Interesting experiment. Thanks, Charlie

Thanks for the answers . VERY interesting , imho.

psychomotors wrote: ↑Sat Oct 07, 2017 7:08 pm Thanks for the answers . VERY interesting , imho.

Thanks psycho - appreciate your approval.
DV

Wow, no wonder no one postulated the explanation!

I figured you may be making another one of your tools, you still need to find someone to produce and sell your rod to block clearance tool and probably a half dozen other tools you have designed.

Thanks for the final "reveal"......

Interesting and useful tool.

The only thing I have a problem with is the blatant advertising and the "suspenseful" delivery. Yes, you are correct: this is entertainment for a lot of us, as engine building is not really a job for me. I enjoy it that much.

However, IMO, ST threads are not meant to be soap operas. You know as well as I do, that starting a thread with a "teaser", then going away for a few weeks, only maximizes the thread exposure. Again, to me, that seems like a deliberate advertising ploy. Only you know the real motives behind the posts. If it's your intention to only use ST for advertising purposes, then that's on you. If it's your intention to only post to help, then maybe a revamp of your post delivery is in order.

If we were all allowed that amount of rein, ST would become nothing but a marketplace, instead of a place for the brain trust to meet.

MadBill wrote: ↑Sat Oct 07, 2017 10:58 pm Wow, no wonder no one postulated the explanation!

Some of us were close

I've heard of people motoring assembled shortblocks to break in the rings and cylinder walls, never thought of breaking in the rings separately like that!

I'm interested in the results of that ring break in set up. I don't take % and best worst case scenarios but I do take direct comparisons shown either on performance in a certain application(car etc) or dyno.

So what method did you use before this, and how is this better other than saving time??

So who earnt the free set of steak knives?

Firstly the pistons have the crown machined with a hole that will accommodate the rod coming through. The piston is then mounted on the rod upside down. With the wrist pin above the top of the deck it can easily be removed to allow the piston to be removed from the top of the block. The reason for this is so I can quickly access the rings and replace them as required. The rotating assembly will be turned over at about 200 rpm max (I did say as a clue that the rods would last almost for ever even though they are welded) The purpose of this 'fixture' is as a ring break-in and polishing machine.

How does the heads fit on it?
(and intake I guess)