Jackfit

To update engine rebuild on my 66 L79 , matching # original engine. As you recall, I am restoring my car, owned for 40 years. Engine was rebuilt 5 years ago and sat on stand (new hips and knee put it on hold). Put in car this fall and had low oil pressure and dirty oil. Found out that no oil plugs were install in front of engine and had over 40% leak down pressure in 6 cylinders. Carl Hinkson of CNC NorthEast is rebuilding engine and I will be installing it this week. Leak down was cause by not plate honing cylinders during other rebuild. Not putting in front oil plugs was just a bad engine rebuilder.

Here are some pictures of the engine rebuild. Picture of Carl with sonogram, picture of block before rebuild, cylinder honing, line honing, pin bore honing of pistons , torch block.

I hope to finish interior this month and get car painted by end of summer.

Next spring I am off on 3 month trip across US to visit 30 year plus owners of corvettes and others for research as stated in other posts.

I will let you know how this rebuild works next week

Jack

Tom Austin

Jack,

Progress looks good. Good luck with your restoration. I've owned my 66 L79 roadster for 34 + years . . . stop and see me on your trip!!!

Tom

Shurshot

I consider plate honing to be a mandatory and especially so with factory blocks. Personally I prefer them in place for boring with the caps also torqued in place however this is the first time I have ever heard that not using one for honing caused such severe problems......... maybe to much original bored clearance also contributed to that problem.

BTW if you get near the Charlotte NC area and like to stop by you are welcome. There are a few forum members around "greater Charlotte"

Doug

Bluestripe67

Jack,
Glad to see things are moving forward. Don't forget we talked 2-3 months back about you coming through surburban MD. on your travels. Dennis

Jackfit

You are on my to visit list. I hope to start trip (drive 300 to 400 miles to get out of New England first) in western NY and head west along the northern and central mid west. Go to Northwest, head south to Cal and head east along the south west. East to the south and north along the south east coast, mid Atlantic and finally New England. I know the car will last, how long my butt will is another matter. I will have a laptop with me and will contact people as I move along , following the wind and roads , good food, good drink and good people.

Jack

427Hotrod

With Carl doing the job...I can guarantee you that there won't be any future problems! That will be a nice tight dry engine! You selected a great builder this time!

Looking forward to hearing about the road trip!

JIM

CWPASADENA

You said you had low oil pressure and dirty oil. No pluges in the front of the block will definately cause low oil pressure but should not have caused dirty oil. Thru the years, I have run across several SBCs that had dirty oil after a complete rebuild (fortunately, not by me) and found the plug in the vertical oil galley at the rear of the engine was left out and I bet the first rebuilder also left out this plug.

There are two horzontal oil passages from the rear vertical oil galley that go to the oil filter. These horzontal passages are about an inch above one another. The lower one feeds all the oil from the pump to the filter and the upper one returnes the filtered oil to the vertical oil galley which feeds the rest of the engine. There is supposed to be a plug in the vertical galley between the two horzontal oil filter passages. This plug prevents the unfiltered oil from the pump from bypassing the filter and continuing up the vertical galley. If this plug is left out, none of the oil from the pump is filtered and dirty oil is allowed to circulate thru the engine.

A lot of people do not remove this plug because they do not know it is there, but a lot of rebuilders will remove this plug so this vertical galley can be cleaned. Good re-builders will make sure this plug is in place when the engine is assembled.

It is easy to check to see if this plug is in place on an engine that has been assembled. You can made a tool out of a piece of welding rod. (1) Measure the "Hight" of the block, from the machined pan surface to the machined intake manifold surface. (2) Cut a piece of welding rod that is one inch longer then this deminsion. Bend one end (the last inch) over 90 deg. to the long portion of the rod. Now, remove the oil pressure line and the fitting at the rear of the block, back by the distributor. Drop the rod down the hole (which is the main vertical oil galley). If the rod will not go all the way down, and the end of the rod is an inch or so above the manifold surface, there IS a plug in place. If the rod goes all down to the bent over end, there is NO PLUG. Note, the bent over end of the rod will prevent the rod from falling down in the engine if there is NO plug in place. The plug can only be installed from below. You have to removing the pan and rear main cap. Check with your machinest if you find you have this problem.

When this plug is left out, most of the time the bearings will fail before the engine is run very much.

Just some suggestions, but it sounds like you have a good man on the job and I am sure your "New" engine will work out just fine.

Chris, CWPASADENA

Jackfit

Thanks Chris,

The dirty oil for the most part came from the poor job done on the engine boring. The cylinders with the heads on were out by .003. With the the heads off they were .001. The rebuilder did not use a torque block for the job. The leak down was 40% or more. I did drop pan and the rear bearing plug was in. Also the plug you mentioned. I drove the car for 400 miles before I got help from forum members. What saved the engine was the high volume oil pump that was installed.

I have attached a picture of the front of the engine with the timing cover off. Those are my lifters on the lower two holes. John Z was amazed that I did not do more damage considering that all three front plugs were missing. My engine has almost 300,000 miles on it. The last rebuilder had to bore it out to .040. In doing so he did not use the torque block, causing the distortion when the heads were put back on.

Carl Hinkson read of my problem and came to the rescue.

Jack

PinkVetteLady

Sounds like great progress on the car! If you are coming up 95 and need anything add me to the list of people that have tools and a spot for you to work if needed.

BLOCKMAN

Well in this case because of the cam there is more dynamic cylinder pressure that will push dirty combustion debris in the base..

And because the block was bored .040 over the cylinders will distort a little more as thats what we found with the plate was put on the block and at the top of the cylinders we found .003 distortion as it hard for round rings to seal in a square bore so to speak!!

We did find some issues with the main line as you could actually see that the housing bores we not in line with each other.

We did find one rod with the cap cracked and being a 365 horse rod it was a hard one to locate as I could find all kinds of 250 horse and 283 rods.

Also when the pistons came out there was a lot of oil between the rings do to rings not sealing.

This is a perfect example of a BUDGET build gone wrong as we have sure leaked down a lot of builds where guys thought they were getting a good job done and in the end it has to be rebuilt again using better machine shop practices.

It will be interesting to see what it will do on the dyno when its done!!

One thing for sure it should have better oil prssure LOL.

BLOCKMAN

The cap under the rear cap was installed and I removed it when cleaning.

BLOCKMAN

The press in plug on the drivers side of the block under the head was not pulled out and because there is no way to clean that passage out when cleaning the block and I have seen this over looked many times as machine shops seem to lazy. This passage can not be reached with a brush unless the plg is pulled out.

Once the plug is pulled out we counter bore it 9/16 to the step and tap 1/4 pipe and during assembly we install an 1/4 pipe plug.

There are some blocks that have a 1/4 pipe plug in the location but most of the 327 blocks have the press in plugs.

Here is a pic to look over

Jackfit

If you have ever had your engine rebuilt, you know that feeling when he calls and says it will be ready in a few days. Your heart beats faster, you start to fantasize , you can hear the engine , you know, also you know that he will probably call and say a part is late or some other delay will cause you to wait. But this time off we go on Friday to put the L79 on the dyno. Here are some pictures of the engine just before heads and rest of gear is put on.

Jackfit

Cstraub69

Well your in good hands with Carl working on your engine. He is top notch in my book.

Engine Doctor

As an engine builder I think it is sad to see these type of problems occure ! It does'nt help anyone...
In my neck of the woods (So Cal) most shops are gone do to substandard workmanship or moved out of Ca. etc.
Anyhay, I don't know how other builders like to do things...but I can give you some input
Building one "None Production" Engine can take more than 60/80 hrs
if done properly...if not longer.. What I tell my customers is that getting an engine built is no diff. than any other consumer product...U get what u pay for!

A few pointers I have:
1. Blueprint the engine/aka check all oil clearances,piston to wall,ring
end gaps etc...and on and on...takes mega time..but is a must!
2.Check oil pressure before installing engine in car.Shop Carefully
There is much more to building an engine..I can go on forever,just here
to help.

Jackfit

Well after a few delays , Today, Sat, is the day we start the engine on the dyno. I will update forum later, it is 5:30 am, I had problems sleeping. I wonder why.

Jack

66BlkBB

Which route are you taking to get to the Northwest. I-90 or I-94? I-90 is more picturesque. Takes you though IL, lower WI, lower MN, into SD at Sioux Falls. From there you get to roll west to Black Hills and Mount Rushmore. Then through WY and into MT. More truck traffic on this route to the NW.

I-94 has a lot less traffic on it once you get past the WI Dells where I-90 breaks away and runs through southern MN. Only problem spot would be Mpls/StPaul and if you get there around 9:30 to 10:00 a.m. you will miss all of the rush hour traffic. This route takes you through ND and into MT. Not much to see in central MN or eastern ND. Western ND has the Painted Canyon and Medora along with Teddy Roosevelt National Park.

Both routes will ultimately wind up just outside of Billings MT where I-94quits and I-90 keeps going west to the Seattle area.

Good luck on your trip. It is to bad that the CF doesn't have a listing like the NSRA does giving all the names of members in different cities and states, just in case you run into problems along the way and need some assistance. That would give a guy a lot less anxiety when making one of these trips knowing that there is help out there.

Steve

midyearvette

don't forget to wear your pants jack!!

Jackfit

Results of Dyno of my L79. We know the problems and Carl Hinkson , CNC NorthEastBlock , said he could fix my engine. He kept his word. The engine started on the first turn of the starter and after a few minutes of adjusting and calibrating, we were ready to run it up. First run was ok and it was obvious that my carburetor needed some float adjustment.

3 more runs with my Holly and the results were very good considering that my engine has close to 250,000 miles on it.

Torque peaked at 380 ft lbs

Horse power at 315

This is with 9.2 ratio not the old 11 to 1. My original pistons were lost 25 years ago.

Engine lost some at top end because of points and distributor wear and the Holly secondaries were fat.

Last run with better carb got 325 HP , but still had iginition break up over 5300 rpm

No leaks , no bangs , no clanging, just pure music of a nice running engine. Thanks Carl and all who have helping me on the forum.

Installing it next week, and back to work on the interior and finally , paint.

Jack

PS Almost forgot, Oil pressure at 60 lbs. + and 40 + at idle.

midyearvette

" No leaks , no bangs , no clanging, just pure music of a nice running engine. ".......yeah baby!!.......