lan's engine build and engine build how to

longassname · #1 09-10-2007, 10:43 AM

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.

longassname · #2 09-10-2007, 11:26 AM

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.

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 ******".

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.

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.

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.

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.

SVXRide · #3 09-10-2007, 12:36 PM

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

-Bill

longassname · #4 09-10-2007, 12:38 PM

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

Quote:

Originally Posted by SVXRide

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

-Bill

sicksubie · #5 09-10-2007, 02:11 PM

So are you saying my build is less precise?

longassname · #6 09-10-2007, 02:35 PM

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.

Quote:

Originally Posted by sicksubie

So are you saying my build is less precise?

SVXRide · #7 09-15-2007, 10:11 PM

Quote:

Originally Posted by longassname

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

Michael,
that was a joke

-Bill

SVXRide · #8 09-15-2007, 10:17 PM

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

cdigerlando · #9 03-22-2008, 09:02 PM

Bumping this thread so it shows up within 30 days. This should be a sticky.

Johnybeas · #10 09-14-2008, 05:32 PM

Hey Mike it's been a longasstime... lol since I have read on this thread, I'm too far behind to read it with the patience I have right now, so I just have a few questions. I noticed you no longer offer the separate parts on your site(cams, rods, low compression pistons etc) are you still selling them??

I'm looking to do a build on mine with the 7:1 ratio to use the gt4088R with the help of Big Valley Performance, can I still get the pistons at least from ya??? What all should I get and what do you recommend for clearances and how big of a bore etc.

longassname · #11 09-14-2008, 05:59 PM

I'm not selling the parts anymore but I am selling complete longblocks. You can't trust a machine shop to get the crank right and it takes a few thousand dollars in precision measurement tools to check it. I have a wider selection of cams now and a wider selection of pistons allowing me to build 108 different configurations to suit pretty much any applicaiton. The price is the same no matter which options you choose--$6500.

Quote:

Originally Posted by Johnybeas

Hey Mike it's been a longasstime... lol since I have read on this thread, I'm too far behind to read it with the patience I have right now, so I just have a few questions. I noticed you no longer offer the separate parts on your site(cams, rods, low compression pistons etc) are you still selling them??

I'm looking to do a build on mine with the 7:1 ratio to use the gt4088R with the help of Big Valley Performance, can I still get the pistons at least from ya??? What all should I get and what do you recommend for clearances and how big of a bore etc.

Johnybeas · #12 09-21-2008, 07:54 PM

Quote:

Originally Posted by longassname

I'm not selling the parts anymore but I am selling complete longblocks. You can't trust a machine shop to get the crank right and it takes a few thousand dollars in precision measurement tools to check it. I have a wider selection of cams now and a wider selection of pistons allowing me to build 108 different configurations to suit pretty much any applicaiton. The price is the same no matter which options you choose--$6500.

Gar.... that sucks cause I was gonna have big valley performance build mine for me.... I need the parts though....

longassname · #13 11-29-2010, 08:34 AM

This short block is for sale now. The specs and pictures of the build are of course in this thread: pages 1 through 4.

The high lights are:
Ballanced past 12,000 rpms
Coated ECUtune high silicon aluminum main bearings
Coated ECUtune high silicon aluminum rod bearings
Perfect oil clearances with tolerances 20x more precies than OE
Eagle H-beam rods with arp 2000 rod bolts
8.5 compression forged pistons with thermal barrier top coating and anti scuff sidewall coating, tool steel pins, and stainless rings
.0015" step deck

In short the most awesome short block you could build for forced induction, fully documented, fully proven, and broken in with about 3,000 miles and a 7800 rpm red line. $2,900