Rebuilding a Cadillac 429 engine

A few months ago I bought a Cadillac Fleetwood 1964, awesome car.


It had coolant leaking into the engine oil. I had to take the whole engine apart to discover it had a cracked engine block, more information here:
https://www.v8buick.com/index.php?threads/common-causes-of-internal-coolant-leaks.398321/

I got a new engine for it. I had it sent via transport, went really smooth. I really dig these chrome valve covers, AFAIK cannot get those anymore.



Turned out it was quiet worn. Was thinking to bore it but pistons are just ridiculously expensive for this thing around here, we are talking >1000USD for a set. Got used oversize pistons but they were shot, see more here: https://www.v8buick.com/index.php?threads/alternative-to-oemtools-ridge-reamer-27030.399443/

Both engines had cam surfaces looking like this. Looks like rough casting on the notch. Apparently, this might be something that is called cam spalling. I am yet to find a comprehensive explanation for this. Common internet theories involve corrosion and devlopment of small stress cracks. Then it seems the surface crumbles. I guess metallurgy is involved too because not all brands seem this affected. Surprisingly, one of the cams still lifts within spec.



Current status is that I am waiting for a hopefully good used cam and new piston rings to arrive. Then I am probably good to go on.

What can I say otherwise, if you want a boat size car, Cadillac is THE boat Real wood panels, leather dashboard, chromy awesome interior.

Getting used parts for these in Sweden is a breeze, the community around Cadillac is strong. You get a used engine for around the same price as for a Volvo. And as you can guess Volvo is quiet plentiful here. New parts though You can get most parts you need but prices are often like twice for Buick, and then Buick is expensive already. So can understand people who put a Chevy SB in their Caddies.

 

Todays update, got a used cam and new piston rings.



The cam needs a bit of polishing of surface rust but I think it will be fine. A little worn but seems to lift well within spec. I used calipers for a quick check. Interstingly, I got quiet a difference on one lobe when checking the caliper estimate towards a dial indicator. As such I am thinking the load surface might have been ground slightly offset to the rotational center of the cam. Will measure all lobes with a dial indicator next. After all horror stories I read all the time about new cams I thought I am better off with a used battle proven one.

At first I was a bit disappointed that the rings turned of to be plain cast iron. However, those are better for a worn engine apparently as they wear in better to the cylinder shape.

Below is one cylinder after the first round of honing. I had honed out up to 0.0015" on the cylinders. Not 100% satisfied with the crosshatch consistency. Might try a drill with a fix speed setting and go over them again. I used a 3 stone hone with 280 stones. It seems the recommendation for cast rings are 180-220 though. Also, the lubricant plays a great deal for the surface roughness as well? I got the impression that isopropyl alcohol created a way coarser surface than WD40. Wish I could be a bit more scientific but a surface roughness meter is quiet a bit outside budget

The new rings I got have 0.018" - 0.024" gap from the biggest to the smallest cylinder. Right on the money with no filing. Lucky shot
Cadillacs spec for these 4.1280" cylinders are 0.013"- 0.030". The old worn out rings where at around 0.080" gap.

 

Here are 3 flavors of Cadillac 429 pistons. Left to right

1. Aftermarket (RC). I think this is similar to how pistons usually 1965 and forwards.
2. Low compression piston from 1964. These were used on some export models. The engine block is stamped "LC" for low compression
3. Standard piston from 1964. The volume is about the same as for piston 1

I tried to estimate compression ratios yesterday by measurements but no number added up to nominal 10.5:1 compression. So have to calibrate what I used and try again.



Here is something very interesting I just found. The skirt is supposed to have zero clearance in the bore This explains why the pistons measured larger further down the skirt as opposed where Cadillac specifies the measurement is to be taken.

Cadillac 429 has wedge shaped combustion chambers that should give quiet a bit of quench. Piston top to deck clearance was measured to be 0.031". Any thoughts on the below?



People seem to get by on RON98 gas and sometimes RON95 gas even with the stock 10.5:1 compression. I am thinking maybe it is the quench that does it. Many people report 19.6 MPG and above cruising on straight road at 40-50 MPH.

 

Done a little bit of various lately. Got the sandblaster working fairly well for the first time and stripped down and painted the oil pan. I used zinc primer for temperature resistance and top coated with Bill Hirsch engine enamel, Cadillac blue. I had gotten hands on a spray gun and tried that for the first time. Everything I learned from the airbrush carried over I felt and it went pretty well. Once getting the hang of it it is easier than a spraycan because of better control I think. I worked outdoors so stuff flying around got stuck in there and what not.
I think Ill do the rest with a brush though. Mostly because I dont want to work outdoors, this enamel overspray might be sticky enough in the workshop to attach to things.

What I might do next time is getting a standard 2K paint. Many of them seem to stand up to 150C which should be enough for everyhing but the exhaust side of the heads. Which probably make this Bill Hirsch engine enamel flake off too? Lets see.

 

I'e always considered the 64's to be the most handsome of all prime Cadillac years (68 being a close second), and a hardtop 6 window the best of the breed. Great score, please keep us updated.

 

There are so many nice ones I have problems choosing. Could probably have one each between 59 to 69

 

A nice thing with two engines is that I can take the best from both of them. Had a front cover shootout today. The front cover design is w.r.t. the oil pump is very similar to on Buick 455. Cadillac has specs for the radial oil pump shaft clearance.

 

Picked out the best looking main bearings from both engines to create a new set. Cleaned them with some finer scotch brite variant. Got 0.002" to 0.003" clearance as measured with plastigage. That is within Cadillacs new spec which is great. Next are the rods, which will get brand new bearings.

 

Did try soda blasting for cleaning the piston top and ring land. Not to pleased with it, feels like a hype. Spent like 20$-30$ of soda on just the ring lands and the cylinder heads, and still not that clean. Dust everywhere which promotes further cleaning



The old rod bearings looked a bit sad. Maybe could have polished them up but decided to get new ones.



Actually felt great to get new shiny ones. Measured 0.0015" clearance on this one using Plastigage. That is well within the spec for a new crank, very happy
A little awkward to get the Plastigage in place while tightening everything. Maybe a little glue of some sort could help?

 

So various things since last post. Decided to clean out the engine bay and paint it. More cleaning and painting of the air cleaner among other things. Went with 2k satin black for the air cleaner, engine bay and a few other parts.



Turns out I missed painting the lid a bit as it was dark and I was in a hurry, problem for later.



And a before and after on the engine bay. Super happy with how it turned out. It is far from a premium job, but very nice improvement for ~8 hours of work or so.






Other than that had a close look at the cylinder head. Ended up replacing all guides, used pre-machined stock guides. For once a part that was affordable.

 

So today I tried the somewhat berated method of lapping/grinding the valve and seat using a drill.
I know, I know, this is not a premium way to do it. The shape of both surfaces becomes a bit off from conical. If the seat is pitted but the valve smooth it might take off more material than I would like for the valve face. Etc. But, I suppose it will match the longevity of the worn cylinders so might not be too bad.

Chucked the drill directly on oiled valve stems. What I can say so far is that it cleaned up pretty ugly surfaces from pitting. I tried to be smart and listen for engagement at various rpms, but in the end it seemed that having the drill on full speed was fastest (little surprise). Little worried to damage the valve stems and guides, but keeping them clean and oiled seemed to leave them without harm. Measured the diameter after.

It is pretty boring and repetive, spent 10-20 minutes on each exhaust valve so far. They all looked like below. Will probably buy one Neway cutter next time, if anything to reduce a tedious and noisy task. It seems that Neway CU234 might work for both the exahust and intake on these 1.5" and 1.875" valves. Delivery time was 2 weeks though and it is time to for the old Caddy to be back on the road ASAP




And here is after 10-20 minutes of lapping with a drill. Not the same valve but it ended up somewhere around this.

 

More painting, this time applying Cadillac blue Bill Hirsch engine enamel with a brush on the intake. It was sand blasted to almost bare metal prior. Did not bother with primer as the can says you can get by without on cast iron.





Result was ok, but I expected more for this quiet ambitious prep job. The gray cast iron color shines through a bit. Seems the paint did not adhere to and cover the peaks of the rough cast surface.



Maybe spraying it would have fixed it, here is a quote from another thread on the subject. I remember I had a similar experience when brushing on another enamel on the Buick intake.

 

I lapped the last valves today using the drill. A trick I used was to set a timer to 3-5 minutes and run the drill until the alarm rings. Made it easier to keep up with the bore and maybe getting more consistent results. All in all I spent between 3 to 20 minutes grinding on each valve. Then cleaning, prep and checking with blue marker on top of this.

I mounted 4 of the still worst valves and poured water into the 2 combustion chambers. It seemed to at least pass this bare minimum leak test so I think I am good to go. Ready for engine assembly it seems, pretty psyched

Ran one of the last cleanings, put these parts in the ultrasonic. Ultrasonic cleaning was not the general miracle cure I hoped but for these parts it was amazing. You should have seen what they looked like before, came out like new almost.

 

Got the valves mounted today

Did plane the exhaust flanges on the heads first. Used 80 grit glued to a fairly flat aluminium beam. Photo from somewhere in the middle of the process. Checked with a proper machinist rule, ground surfaces became dead flat in the end.

 

Also measured the cam lift. Was very well within spec. The measurement setup might look wonky but repeatability for several revolutions was often within 0.002", which is way better than I think need.

 

I use a petroleum based product for valve seal test, like mineral spirits or thinner. This video link shows the procedure and US military spec for aircraft valve seal which was amusing and informative, for me anyway.

 

Thats is nice! I will watch that after putting the engine together for next time, because I am pretty sure this backyard valve job will not pass any more stringent tests Lapping with a drill leaves fine horizontal lines on the surfaces. Hopefully they will wear and flatten a bit over time.

I had a major headache with the transmission guide pins. There is an adapter plate from factory between the engine and transmission. Reason being Cadillac 1964 came with two different transmissions. The guides for the adapter were larger on the new engine. So many questions. Was it concentric to the guides on the old engine? Did someone tamper with it? Did Cadillac change something midyear? Googling around it seems around 0.005" concentricity between the crankshaft and torque converter is desired, so did not want to take too many chances. Wrote a thread on it here: https://www.v8buick.com/index.php?threads/th400-to-engine-alignment-tolerance.400017/

I went out to to inspect the old cracked block. Then I saw that block had guides with a two step diameter! Did not see that coming, was thinking two much in the box. This was like a gift from above, one more box ticked. It seems that cars that came with Turbo Hydramatic transmission (like my Fleetwood) have these two staged guides, while the old 4 staged Hydramatic one have a homogenous diameter.

 

Now it is getting real! Crankshaft and first piston is in Left the others early at the bar to be real fresh tomorrow sunday and continuing, I am that psyched now
Was a real workout to torque down the caps when assembly lube was on. Screws felt soft and it just kept going, thought I was about to break a bolt. Then I realized it must be the lube pressing out gradually. Maybe overdid the lube little bit. Everything spins like a clockwork anyway



And piston number 1 is in the bore with brand spanking new rings.



The shop manual recommended some sort of rubber glue on the main seal ends and below the cap. I put a little RTV instead. That little piece of rubber for main seal was around 100 USD btw Considered reusing the old one and it probably would have been fine. But would have been such a pity if everything ran fine and it leaked.

 

Yesterday the last pistons went in! Took out one piston again to double check that oil ring expander butted correcly. Was hard to get the piston out with the new rings locking against the ridge. During disassembly pistons almost fell out by gravity

I wanted to save painting for when everything is assembled. However the ludacris drying time of Bill Hirsch prompted me to do it now. That is because I want to be able to fire the engine right up once finished with the assembly. For painting I wanted the freeze plugs in. These freeze plugs holes are shallow, and the freeze plug is just a dish with no collet. Bottomed with RTV for extra safety.






Painting a semi assembled engine is the worst because you have to keep grease and oil close to paint, and conversely paint, overspray and occasional grinding close to an open engine. Like two mortal enemies stuck in an elevator.

I did a very quick mock assembly to aid in masking. Used a valve cover and oil pan I will not use for masking. Btw, the old paint job someone did had left pain in the tubings around the oil pump and on the valve springs

I used a HVLP gun for Bill Hirsch this time. Good good coverage at once on the aluminium front cover. However the spray gun clogged and had to finish with a brush. I think I finally got punished for omitting filtering the paint. Hirsch doesnt work to well with a brush, compared to cheaper stuff I have used.

 

Found this picture of what it looked like before I flushed the block using a high pressure washer. You could scoop out gunk.

I noticed they had one plug replaced using the expander type. And the other engine had a leaking plug. So I think replacing all plugs was a called for as a pre-emptive measure also.