lan's engine build and engine build how to
 

In this thread I will document the build of the engine going into my ebony SVX. This engine is being built with the same ECUtune parts being used for the EG33s being put together for forced induction by other members of the forum but a noteable difference in the build is that I have the tooling to ensure a higher level of precision in the machining and assembly of the engine. In this thread I will share pictures and explanations on how this level of precision is attained.

I started checking the machine work on my bottom end in order to prepare for assembling my engine. First let me say this isn't something you do the day you expect to put the engine together. That would be assuming you won't find any problems and as my case illustrates that isn't a fair assumption.

Here's a picture of my crank. It sure looks great and up until about half way through my check it measures out great too.
http://www.ecutune.com/posts/crank/DSC_5057.jpg

Here's my NSK Japan 2-3" outside micrometer closed down on a 2" standard and zero'd out. (I kind of collect nsk japan micrometers). It is accurate to .0001" which in technical jargon is commonly called a "ten" which is short for one ten thousands of an inch. The first use of this micrometer is to measure all of the crank journals and crank pins. The crank pins are what the rods connect to. The crank journals are what ride inside of the block. We take two measurements of every journal, 90 degrees apart to check for roundness/out of roundness. Everything checked out round and my pins measured to ******" and my journals to ******".
http://www.ecutune.com/posts/crank/DSC_5058.jpg



So far so good. The next thing we need to do is make sure our crank is straight. To do this we install bearings into the odd number cyllinder block for the #1 and #5 journals. I actually don't have the correct bearing installed in the #5 location in the picture. It wouldn't matter for this test but I corrected it anyway because in the next step we will be installing all the bearings.
http://www.ecutune.com/posts/crank/DSC_5060.jpg
We then drop the crank onto those bearings and isntall a dial gage to the block so that we can check for run out. I use the keyway in the crank nose as indicator for how far I have rotated the crank. Rotating the crank 1 full revolution any bend in the crank will show up as run out--the difference between the high and low measurement displayed on the dial gage. The dial gage is zero'd out in the picture but it doesn't have to be. The only thing we are looking for here is a movement in the gage. If there is no bend there is no movement in the gage reading at all. Everything looked good through journal #5 then I found 5 tens run out on journal 6 and 12 tens run out on journal 7. Visually that means on needle moved half a tick mark on that gage on #6 and over 1 tick mark on that gage on #7. That means there is a small bend in the crank between journal 5 and 6. I need to send it back to the machine shop.
http://www.ecutune.com/posts/crank/DSC_5063.jpg



The next issue is our oil clearances. The home mechanic typically uses plastigage to to check his oil clearances but plastigage is only acurate to 5 tens. I can do much better. I have a digital bore gage certified to .00005" The bore gage has to be set with a standard and I'm using my 2-3" outside micrometer as the standard so that limits my acuracy to 1 ten but that is 5 times better than plastigage before even considering reliablity and repeatability. Plastigage also doesn't give you #'s you can use for machining; it just tells you if someting is acceptable or scary.

What we want to do is cage the bearings. Caging bearings means installing them into the block and into the rods without the crank and then measuring them. The difference between the outside micrometer readings of the crank and the bore gage readings of the bearings is your oil clearance. You will find that the readings of the bearings in the factory parts, particularly the main bearings have a large amount of variability.

http://www.ecutune.com/posts/crank/DSC_5066.jpg
http://www.ecutune.com/posts/crank/DSC_5068.jpg

The eagle rods I am using are ground much more precisly than the block and have very little variability. My caged rod bearings have a bore of ******" to ******" giving me an oil clearance of ** to ** tens. This is a little tight but I am using coated bearings so 4 tens of that is dry film coating. This is as tight as I'm comfortable with but i'm comfortable with it and won't have them mess with the crank pins anymore.

The bore of the caged main bearings had 8 tens of variation. Remember my measumrents indicated that the machine shop ground all the journals to the same size even though I had paid them to cage the bearings and grind accordingly. Obviously I have 8 tens of variation in my oil clearances with oil clearances ranging from 1 thousandth to 18 tens. This I am not happy with. I'm going to go ahead and get a set of larger bearings, cage them myself, and specify the size to grind each journal to.

Michael,
Very, very nice! So, who's Ian (your alter ego?)?:D
-Bill

um that's an L...every on here calls me lan so why fight it

So are you saying my build is less precise?

Is that insulting to you? My understanding is that your engine has the factory oil clearances and that Tom checked them with plastigauge and didn't find anything scary. I'm just describing the process to move the tollerances out another digit.

Thanks
 

Very nice. Thanks for the write up. Good thing you checked your crank with the dial guage. You can't pay for that kind of piece of mind.

thanks,

lol, I paid for it..I just didn't get it.

I said that in jest.... I have 110% confidence in the work that Tom did.:)

To be honest Mike is gonna need his tolerences to be larger and more precise for his plans... Running tons of boost and hoping for over 600awhp you are gonna need it. For Bobby and my builds, we are not going to that extent and a tighter motor will leave us with more longevity. Our clearances are to the upper end of the spectrum for stock clearances and I think we are perfect right there

Tom

The cyllinder heads are ready to be sent out for thermal barier coating of the combustion chambers and exhaust ports and I've made crates to send them out in.

They are ported and I do mean ported not port matched. What was done is kind of hard to grasp unless you've actually done it before and probably impossible for me to explain but maybe you can visually see how free flowing they are now. There was a lot of room for improvement just cleaning up the castings. There were some pretty nasty ledges and missmatched surfaces around the valve seats so removing those was 1st and foremost. After removing the casting seams and cast surface it was obvious there were some great opportunities for improvement in the bowls and deep in the ports.


Here are just a couple pictures of the heads:
http://www.ecutune.com/posts/porting/DSC_5085.jpg
http://www.ecutune.com/posts/porting/DSC_5104.jpg


Here are a couple of close ups of combustion chambers where you can kind of get a look out of the intake ports:
http://www.ecutune.com/posts/porting/DSC_5111.jpg
http://www.ecutune.com/posts/porting/DSC_5136.jpg


Here's a close up of a combustion chamber where you can see some exhaust bowls:
http://www.ecutune.com/posts/porting/DSC_5150.jpg



Here's a look down an intake port:
http://www.ecutune.com/posts/porting/DSC_5145.jpg

Michael,
that was a joke;):)
-Bill

Michael,
Beautiful work on the heads! Did you do them yourself, or farm it out? How many hours went into each head?
-Bill

For time's sake I was going to have someone else do them but I got tired of leaving them sitting around their shop and gave up and did them myself. I'm well tooled up it and know what I'm doing so I decided to just sit down and knock them out. I'd say I personally put 12 hours of solid porting into them myself. I have another shop that dissassembled them, knocked down the guides, and then reset them and bead blasted the ports and chambers, and surfaced them when I was done.

did somebody say 600awhp? My interest is piqued :)