CorvetteForum - Chevrolet Corvette Forum Discussion

CorvetteForum - Chevrolet Corvette Forum Discussion (https://www.corvetteforum.com/forums/)
-   C3 Tech/Performance (https://www.corvetteforum.com/forums/c3-tech-performance-3/)
-   -   My 406/409 SBC build with Bubba! (https://www.corvetteforum.com/forums/c3-tech-performance/4278190-my-406-409-sbc-build-with-bubba.html)

bmans vette 05-25-2019 08:24 PM

My 406/409 SBC build with Bubba!
 
Lots of inspiration on the forum lately as we get into nice weather.
I went through many, many challenges last year as some of you well know.
Most of them are in the past ....time to move on.
I get my greatest reward from building things.....as I am sure many here do also.
Last year I picked up a SBC 400 from a young guy who had it in a dirt tracker. It was listed on craig's list locally so no sweat checking it out.
He was storing it at his GF's parents place and it had to be moved.
What the heck...go check it out.
He had started (or his friend did) a tear down because it had failed them on the track.
So the heads, intake and carb were off. The distributor was gone. But water pump, alt and PS unit all still on it.
And the flywheel.
Block looked like a recent build but he thought there was a wiped lobe in the cam.
Started out to just to buy the block (actually a short block) for $500
Got there and he had a set of Dart Pro 1 heads 230cc, Victor Jr intake, Holley carb
He wanted $1100 for the heads but they would need a freshening up.
Kid was anxious to sell and I had CASH.
Got EVERYTHING for $1300.

Hauled it all home....fast forward 2 months and I am in Emory Hospital about to have 3 cardiac surgery in 30 days.
Recovered in December but had to get caught up on my outside business projects.
Rehabbed 2 houses in 5 months, gutted another and sold the 2 rehabbed ones.
Closed last Friday on both.

Cash and time are now mine......

So 3 days ago decided to start tearing down the block. It had a bit of rust in 2 cylinders from sitting.

I will start by saying....even though this kid raced this car and someone had some skills who built it........Bubba was alive and well.....

Pics to follow.
My plan is either a 406 if I can reuse most of the short block or go to a 409 if I need to overbore it to 4.165 which is close with a 400.
I picked up a brand new set of Dart 200cc heads to use on this as I have a Dart SHP block in the wings waiting for a 421 build. I'll use the 230cc heads on that.
All my engine experiences have been 350s and 327s over the years with Chevys. Throw in a couple of Fors, Hondas and even a couple of Jeeps.
Was a line mechanic for many years in my youthful days.


Enjoy!

Feel free to comment.....like to hear from some old friends I haven't heard from in awhile and some new ones recently acquired.

My car projects stalled so getting a couple of engines done and tucked away will get me going on those. Plus I have one Super 10 rear and working on another 4.11 rear. Throw in 2 T56 trans that need tear down and beefing up and I have plenty to keep me busy.

Dennis (or Bman) :auto:

bmans vette 05-25-2019 08:32 PM

https://cimg9.ibsrv.net/gimg/www.cor...42425e6a2a.jpg
https://cimg5.ibsrv.net/gimg/www.cor...ceb550c66a.jpg
https://cimg9.ibsrv.net/gimg/www.cor...0da3a68589.jpg
https://cimg1.ibsrv.net/gimg/www.cor...1971d6916e.jpg
https://cimg3.ibsrv.net/gimg/www.cor...3ae3459af1.jpg
And so it begins....off with the pan and figure out what I have...

Unfortunately phone battery was empty and did not get pics of lower end before pulling it out.

bmans vette 05-25-2019 08:44 PM

https://cimg4.ibsrv.net/gimg/www.cor...92454a0dbe.jpg
https://cimg6.ibsrv.net/gimg/www.cor...e438acbfef.jpg
Yes we do have a wiped cam lobe...#8 exhaust

jackson 05-25-2019 08:45 PM

:thumbs:
You really don't know for certain why the motor was sold cheap.

Pull motor down & pay shop to mag block & measure bores & if it'll clean up with hone. It's probably pretty good.

Assess crank, rods, pistons & know exactly what you have.

Same for heads.

You probably have mostly good stuff & good deal but don't begin a build without first KNOWING.

bmans vette 05-25-2019 08:51 PM

https://cimg8.ibsrv.net/gimg/www.cor...21edb16a1b.jpg
https://cimg1.ibsrv.net/gimg/www.cor...200a260d0e.jpg
Want to guess why the cam lobe wiped?
Can you say starvation for oil?

That wad of gasket material was literally sucked into the pickup screen.
Yeah Bubba!

bmans vette 05-25-2019 09:01 PM

https://cimg1.ibsrv.net/gimg/www.cor...81542eab76.jpg
https://cimg8.ibsrv.net/gimg/www.cor...15d654c8a3.jpg
https://cimg9.ibsrv.net/gimg/www.cor...b6fdf9446f.jpg
So let me back up and fill you in what I discovered....
When I went to take the oil pan off, I found it was bolted on with 7/16" cap screws. The heads are too big actually for the rail where the pan is bolted down from.
Bubba forced them.
Lots of dings from the wrenches he used.
So he could not get a good seal....
So what does he do you ask?.....What crappy house carpenters / painters do in this case....CAULK IT!
LOL

Check out the thickness of the gasket sealer on top of the cork pan gasket under it.

bmans vette 05-25-2019 09:20 PM

https://cimg0.ibsrv.net/gimg/www.cor...be7df368ca.jpg
https://cimg6.ibsrv.net/gimg/www.cor...e68ab2e6a2.jpg
https://cimg7.ibsrv.net/gimg/www.cor...ba00130b51.jpg
Full view of pan gasket.
Notice double nutted stud in foreground of pic.
See the allen wrench in top of one of the studs.....would not budge.
Studs are only supposed to go in finger tight....you tighten the nut (bolt stretch gauge or torque wrench install)....right????
I ended up double nutting each stud to get it out.
ARP studs and bolts used in engine everywhere....Bubba just never read the instructions....

bmans vette 05-25-2019 09:29 PM

https://cimg9.ibsrv.net/gimg/www.cor...307b2355a7.jpg
Dart Pro 1 230cc heads
https://cimg8.ibsrv.net/gimg/www.cor...8f948b4e79.jpg
Probe pistons on top of Eagle rods with ARP 8740 bolts
https://cimg7.ibsrv.net/gimg/www.cor...c0285cad4b.jpg
Probe pistons but cannot find part #
https://cimg2.ibsrv.net/gimg/www.cor...638cd18ef0.jpg
Note ARP rod bolts.....
https://cimg5.ibsrv.net/gimg/www.cor...75f979cf79.jpg
Eagle crank. Supposed to be cast but rings like forged one. Cannot identify part#
https://cimg0.ibsrv.net/gimg/www.cor...4b5cbe515c.jpg
Victor Jr intake and Holley carb
https://cimg7.ibsrv.net/gimg/www.cor...f05229f7b9.jpg
Timing cover and mini starter.
Some of the pieces that came with the deal....

jackson 05-25-2019 09:32 PM

Right or wrong ... lotsa guys loctite the studs.

So ... what's crank look like ?

bmans vette 05-25-2019 09:37 PM


Originally Posted by jackson (Post 1599466666)
:thumbs:
You really don't know for certain why the motor was sold cheap.

Pull motor down & pay shop to mag block & measure bores & if it'll clean up with hone. It's probably pretty good.

Assess crank, rods, pistons & know exactly what you have.

Same for heads.

You probably have mostly good stuff & good deal but don't begin a build without first KNOWING.


I know that.
Teardown was first step.
Already been to local speed/machine shop I use to check schedule for magnafluxing the block.
But I have more prep work before I do that.
Knock out galley caps and tap for plug replacements. Including the one back by the oil pump. Shops miss that one sometimes and crap sits in there.
Remove all knockouts/freeze plugs.
Clean all oil galleys with brush and cleaners and blow out.
Grind down flash at oil returns and clearance the oil filter return.
Degrease/pressure wash and air blast it dry

NOT my first rodeo......

Thanks :thumbs:

Then we will see what the shop says and go from there........:steering:

jackson 05-25-2019 09:38 PM

Look like eagle SIR rods w/ capscrews

is flywheel counterweighted.

is damper counterweighted?

bmans vette 05-25-2019 09:49 PM


Originally Posted by jackson (Post 1599466883)
Right or wrong ... lotsa guys loctite the studs.

So ... what's crank look like ?

Posted one pic of crank. Looked at backside of all bearings used...Clevites and marked as std so looks like it was not turned.
Bore measures 4.155 with just a quick caliper gauge. I'll check each cyl with my bore gauge before it goes to the shop.
Not much room in here for boring out. Especially if out of round or sloppy work before.

LOTS of chasing info first.......

Thanks for your comments though.

May pick your brain later...have GKull and Jebby on my list also.

:thumbs:

bmans vette 05-25-2019 09:55 PM


Originally Posted by jackson (Post 1599466933)
Look like eagle SIR rods w/ capscrews

is flywheel counterweighted.

is damper counterweighted?

Agree on rods but have not had time to measure actual length. Some grinding on bottom of a few caps.
Everything is up for replacement if necessary.

Neither flywheel or damper counter weighted so internal balance. Some metal removed on the crank at the counterweights but not sure if that was when balanced in shop or manufacturer.

I'll be having the final rotating assy balanced anyway so we will see.

500hp target so nothing cheap and nothing done poorly.

Kacyc3 05-25-2019 10:04 PM


Originally Posted by bmans vette (Post 1599466987)
Posted one pic of crank. Looked at backside of all bearings used...Clevites and marked as std so looks like it was not turned.
Bore measures 4.155 with just a quick caliper gauge. I'll check each cyl with my bore gauge before it goes to the shop.
Not much room in here for boring out. Especially if out of round or sloppy work before.

LOTS of chasing info first.......

Thanks for your comments though.

May pick your brain later...have GKull and Jebby on my list also.

:thumbs:

When mine lost oil pressure I had the shop check the cyl. To see if it could be bored for forged pistons instead of going .040-.060 over. I wasn't comfortable going .040 + on a street 400.

bmans vette 05-25-2019 10:13 PM


Originally Posted by Kacyc3 (Post 1599467079)
When mine lost oil pressure I had the shop check the cyl. To see if it could be bored for forged pistons instead of going .040-.060 over. I wasn't comfortable going .040 + on a street 400.

Interesting....
This is my first 400 sbc. Like I said all 327 or 350s before.
We all know the horror stories/urban myths over the years about 400s and their wall thickness, etc.
Most of what I read said that a shop will seldom bore a 400 .060
Which is why I am considering .040
Already made sure that my shop quotes me that cost with torque plates.
But maybe he will get a clean look with just a hone.
Like I said, not planning on re-using everything.
At this point the heads, intake carb and whatever I sell off the miscellaneous parts for makes the block basically free cost to me.
We will see...
Stay tuned.
Thanks for your input also....have see some of your threads.....:thumbs:

bmans vette 05-25-2019 10:19 PM


Originally Posted by jackson (Post 1599466933)
Look like eagle SIR rods w/ capscrews

At least they are the ARP 8740 cap screws and not the L-19s
:nonod:

cv67 05-26-2019 03:12 AM

Youll love the 400 keep at it, love to tune them heads up!

L88Plus 05-26-2019 07:18 AM


Originally Posted by bmans vette (Post 1599466692)
https://cimg8.ibsrv.net/gimg/www.cor...21edb16a1b.jpg
https://cimg1.ibsrv.net/gimg/www.cor...200a260d0e.jpg
Want to guess why the cam lobe wiped?
Can you say starvation for oil?

That wad of gasket material was literally sucked into the pickup screen.
Yeah Bubba!

Actually got really lucky with that. I've torn down two tall deck 427's that were rebuilt for use as irrigation engines. Both had huge pieces of orange Permatex sucked into the pickups that starved them for oil so badly that they had spun rod bearings. These were fine on the pan rails but had huge gobs still stuck on the inside of the china rails. Next build, I'm going to try a painter's trick: cut a "V" into one side of the tip of the caulk tube to make an ^ instead of the typical caterpillar gob job. As long as everything is clean (I use thinner to remove oil residue, then a quick spray of carb cleaner on the china rail and bottom of the ends of the intake), this should be plenty.

The only issue with .040 and .060 over is poor ring seal, NOT overheating. Thinner cylinder walls actually pass heat to the coolant better and faster than thicker. That old wive's tale originated from people trying to use the same radiator for a strong 406 that had worked fine for a smog era POS 350.

My local shop now has a CNC hone that measures as it strokes and results in very straight and round cylinders. They bolted a torque plate to an old 400 I had with a bit of wear and honed it to .040, saved me the cost of an overbore. Engine runs plenty cool and burns no oil, still running in a friend's truck.

Rescue Rogers 05-26-2019 07:49 AM

Glad you survived the surgeries!! Thanks for all the pics. I cant wait to here it run.

bmans vette 05-26-2019 08:27 AM


Originally Posted by L88Plus (Post 1599468018)
Actually got really lucky with that. I've torn down two tall deck 427's that were rebuilt for use as irrigation engines. Both had huge pieces of orange Permatex sucked into the pickups that starved them for oil so badly that they had spun rod bearings. These were fine on the pan rails but had huge gobs still stuck on the inside of the china rails. Next build, I'm going to try a painter's trick: cut a "V" into one side of the tip of the caulk tube to make an ^ instead of the typical caterpillar gob job. As long as everything is clean (I use thinner to remove oil residue, then a quick spray of carb cleaner on the china rail and bottom of the ends of the intake), this should be plenty.

The only issue with .040 and .060 over is poor ring seal, NOT overheating. Thinner cylinder walls actually pass heat to the coolant better and faster than thicker. That old wive's tale originated from people trying to use the same radiator for a strong 406 that had worked fine for a smog era POS 350.

My local shop now has a CNC hone that measures as it strokes and results in very straight and round cylinders. They bolted a torque plate to an old 400 I had with a bit of wear and honed it to .040, saved me the cost of an overbore. Engine runs plenty cool and burns no oil, still running in a friend's truck.

Thanks for the info.
Like I said...first time with a 400 SBC.
Pistons will have 1/16 & 3/16 rings.
My shop has torque plate equipment but there is another shop other side of town that might be more speed shop oriented and not just your basic rebuild kind of place.
I have the plans and materials to build a test engine stand also. I'll break next couple engines on that before install.
Stay tuned.
I'll post up more pics but heading to Washington DC on Tuesday for BIL memorial service at Arlington.


All times are GMT -4. The time now is 09:25 AM.


© 2024 MH Sub I, LLC dba Internet Brands