428 Continued Tear Down
 

Hi, my friend and I tore down the 428 today and was totally impressed with its condition. engine turned over really quite well with all spark plugs out. The motor looked actually quite fresh, I’m kinda shocked it was sold as low cylinder pressure on #1 but I could not do a comp test as I did not have flexplate prior.

Bearings and bearing surfaces were “really good to just *GOOD* condition at first glance.
Stock CON RODS I think, can’t tell if any modifications were done.

The connecting rod + rod caps were all dot punched correctly so someone tore it apart at least once. The timing chain did have some slope though. It has a crane cam (HE 254 – 2NC *one side* / bd2193 919s cc * other side *) in excellent shape, the “cc” makes me think - made for comp cam by crane but can’t find any specs on this cam.

It had rope seal and 4 bolt main’s. No crap shavings in pan or oil pickup. The crank is as one suspected (97828769 N) .Pistons are down in the hole, pistons are not flat tops which correct me if I’m wrong would be if it was stock from factory? I believe these are el-cheapo ? I found brand name – BOHNALITE backside of piston skirt ??? Pistons walls looked 95% good - cross hatch present but will have to look again for sure.

Heads don’t look ported , no major damage found. Will inspect those more later on.
Someone was saying it should have longer windage tray?

So unclear on pistons ID they are, if they are crappy or not. Assume until I can measure bore that it has not been over-bored. Unclear on CAM ID.

If you notice anything on my pics let me know! Thanks again for all your help.

more pics
 

attached more pics

Looks like they punched #2 rod with 1 dot, and have stamped the even side with an odd number of dots?

So far so good!

Those are the stock 428 pistions and the Bore finish looks real good, so either the motor was freshened up with a ridge ream and hone job or the motor has well kept low miles on it.

Look over that full length windage tray real close for any signs of cracks starting from the multitude of 90 degree sharp corners it has .

I think Kenth is correct on how it was punched on the rods. Probably punched them 1-8 from front to back. At least the pistons have the notch to the front! :D

BTW, the order from front to back on the rods should be 2,1,4,3,6,5,8,7 by cylinder numbering.

:)

Looks like you have one gm piston in there, and those other 3 are not.

Notice the difference in the dish.

Sun tune has good eyes!

I missed that since I did not enlarge the screen.

That first piston at the front of the block is for certain a stock one.

The other three have a bigger OD dish, but it’s not as deep.
I bet the CCs work out the same between the two different styles.

I used to have a set of TRW .030” over forged replacements, but I can recall if there face was like the ones that you have there.

Congrats on the engine and even more, on the condition!

Which pistons were labeled "Bohnalite"?

I'm curious to know if that was a GM supplier or aftermarket.

I Binged the brand and it seems to go back a long ways as a major supplier...

https://en.wikipedia.org/wiki/Nelson_bohnalite

Hi,

I had a look at the pic with the counter weight showing with brass and numbers on it. i can see the "single ." rod there butted up against counter weight and then the ".." double dot next to it so i believe the last guy in here went 1 dot very front of engine and then stamped them going front to rear 1-8.

When i build my new engine i'll probably be using all new connecting rods and will revisit install of #2 cylinder first, then it's #1 cylinder next in line. As JONHTA told me, that's cool. learned something new 2,1,4,3,6,5,8,7


Great eye catching the one piston being stock and all other 7 being a different manufacture: interesting that was the cylinder with low compression ,supposedly.

I'm gonna ask the shop that pulled it and seller some more questions.

I found pistons on ebay:
https://www.ebay.ca/itm/151016413803

Thats wonderful news on this tear down. super lucky . now to find out what the heck crane cam this is. "HE" makes me think high energy line.

But 254 seems like a way too small if you look at my other cams i've ran comp 280 and crane 284. all in my 400. need to find the specs.

It's a ford CAM : lol :

https://www.ebay.com/itm/155195508824


I'll check the windage tray today and find a tool to measure bore to verify it is STD.

Welcome in 2024 on a high note!!! Awesome ...

Thats an old Crane Thriftmaster grind. Smooth idle and economy. It is smaller than a stock 067.

That Cam is far too small for a 428 with high comp heads like you have.

For reference, here is a TRW/Speedpro 428 piston.

Ah yes, finally came across a chevy PDF I saw the thriftmaster . nice name. way to power this bad boy. lol well so much for this being someone's top of the list grind to buy from me.

254/264 190/200 112 LSA 385/408

That Crane cam is very close in spec’s to the factory cam that came in all 1977 TA 6.6 automatic motors.
I will be curious to see how the back side of the rod bearings look and if they show any sign of pounding from detonation due to the cylinder pressure that motor had.

Even the low performance 360 Hp 428 of 1969 used a cam ( 067 ) that could called one step hotter then that Crane cam.

Hey Steve, is that right? 1977 TA 6.6 - 400 type cam. Yah last "refresh" if we can call it that I guess builder choose that cam for economy. Very bizarre choice.

When i'm back home with my parts I can take the bearings out of some of the rods and snap a pic looking at where the bearing sits in the con rod, not con rod cap. If I understand you right?

If rods have been getting hammered then the normal clear impression / transfer of the letters and numbers on the back of the bearings and into the rods due to having good bearing crush will make them look smeared.
Original bearings will have GMA 400 on them.

Interesting, ok so back side of con rod bearings ( both of them ) will have letters on back. Ok I'll post back in next day or so.

For sure I can check that out for you. and post some pictures. thanks again everyone.

I heard one can take this old cam and have a cam company make it into a custom cam grind and that it is cheaper and BETTER than buying a new one?

thoughts?

bearing pics
 

Looks like main bearings are .010 over sized so crank must of be ground .010 over at one point.

here are some of the bearing pics of mains as well as 1 con rod. i will post another pics but the slight wear on some of the con rods bearings did not translate to any noticeable damage under the bearing.

Here are some pics

Couple of little items for you. The main bearings would be more correctly referred to as -.010 undersize because the crankshaft is now smaller. They have a date of November, 1984 on them. 11-84. The Rod bearings are DAB brand. Detroit Automotive Bearing. Used to be pretty popular. Could not see a date on them or an undersize. The block has been line honed. Most likely, the original bearings may have spun in the block making that necessary. You can tell by the cross hatch in the bores. The rods look to have stock bolts and may or may not have been rebuilt. Most people would not re-use them. For a budget build I personally have no issue using them again with new hardware properly rebuilt. I have personally never had a rod failure with a Pontiac engine where the rod was the cause. Cast rods, new hardware, sized correctly, I would respect a 5500 RPM red line. 5800 RPM's, your in the danger zone on a 428 IMO. Overall, engine looks pretty darn good core.