LT Texan

Consensus is that the last one got hot and that was it. This one needs to last. Cost too much to do this every 5 years. Need to get everything together for Thanksgiving.

Short block arrived today.


It's from an early Euro S 4.7L 5 speed.


Heads back from the machine shop (The Engine Co in Mt Vernon NY). And they look good. Two bent exhaust valves replaced. Valve seals. No other parts necessary. Labor $400 for the pair.


And this machine shop has bored out aluminum blocks. He has the equipment. He's done a few Merc's and says he would like to have grown that business. And yes, $100/hole.


He even showed me the last step honing paste.

LT Texan

Not having a very good 928 day today.

Everything back together.

Turn it over, started. Ran long enough to really hear the tappets making racket, then it died. Then nothing.

Have gas (at least pressure to the WUR).

Didn't check spark.

Pulled the fuel pump relay and checked compression on an obviously cold engine.

# - psi
1 - 155
2 - 130
3 - 150
4 - 150
5 - 90
6 - 80
7 - 100
8 - 120

oh no.

BC

where the heads from the same running engine as the block?

Mrmerlin

did you have anything done to the bores?
Did the headgaskets get positioned properly? maybe cutting off oil flow?
how about the tower gaskets?
What was done to this engine

soontobered84

Cylinders 5,6,7,and 8 have significantly lower pressure than 1,2,3, and 4. Something seems amiss.

LT Texan

I dropped some oil in the spark plug holes and tried each one again and got the second pressures

# - psi
1 - 155 - 185
2 - 130 - 175
3 - 150 - 175
4 - 150 - 190
5 - 90 - 90
6 - 80 - 100
7 - 100 - 100
8 - 120 - 140

I think the right bank problem is poor ring seal.

The left bank I don't think I got a seal on the cylinder head gasket.

The heads are off an 86 euro S and have been fully reconditioned by a reputable machine shop. These are the heads I had on my 4.5L.

The short block is used. I just cleaned it up. Nothing abrasive on the deck for cleaning. I did not Re-ring or remove the pistons for cleaning.

The bores all looked good. Made sure there was no debris, oiled them and rotated the assembly. All seemed fine. So I left a thin oil film and started assembly.

I've removed studs before so I could deck an earlier Block. I did not want to go through that again.

LT Texan

And yes the cams line up properly at TDC.

Ad0911

[quote/]

It's from an early Euro S 4.7L 5 speed.


Heads back from the machine shop (The Engine Co in Mt Vernon NY). And they look good. Two bent exhaust valves replaced. Valve seals. No other parts necessary. Labor $400 for the pair.
[/quote]

I payd double of that and that's the regular cost for his kind of job here in the Netherlands

LT Texan

I had him knock $50 off cause I'm such a nice guy!

Maybe he knows I'll be back!

LT Texan

Probably time to pull the engine.

Mrmerlin

the cam timing is suspect on the low cylinders,
even with the low compression it should run, but not well

LT Texan

Yep. I checked the cam gears after the horrible left bank readings.

Dead on. And the gears were not removed from the cams while I did work.

The right bank dowel boss was cracked pretty good. Took it to a welder and he said no big deal just JB weld it and file it down by hand flush with the deck as necessary. Worked fine. Or seemed to.

The studs are all original. New nuts. All seemed to torque just fine. Consistent across all studs. Nothing odd. Nothing seeming to give.

I figure none of the rings are holding up, at least on the right side. Figure head gasket problems masking problems on the left bank.

Definately pull the engine back out and take a look at each piston. This short block set for a few years, but not neglected. I'm surprised by the problems.

Maybe if the pistons look good, punch out my 4.5L to 97mm, buy some rings and see what I can do.

I am a big proponent of decking the block, but I don't want to go through stud removal.

Damn it all adds up.

fraggle

Good luck!

Got my 32V heads decked, seats and valves cut and all new valve seals installed for $225 two years ago after an unfortunate overheat. Joy joy they're still running great.

LT Texan

Just to close this one off (cross post from my Texas Road Trip Thread)

I finally figured out what happened.

Broken left cam nose. Absolutely could not tell by spinning it in the cam tower assembly. Nothing seemed odd.

But when I put on the left cam tower, the cam did not seem to want to spin as much as usual (off a lobe).

I had it almost all back together and notice that the number 5 piston was on its way up with the valve opening!!!!!

Now it all makes sense. Broken cam nose. Slipped timing. And a couple bent exhaust valves.

Hard to see in the first picture the no. 5 intake valve buried in the intake valve relief.



And the broken camshaft nose.

vze2jshn

Suggestion: Upon reassembly with the replacement cam check specs regarding end play (forward and backward) you may need to have the cam and or cam tower components machined to be in spec. This is based upon my experience with a cam and tower that were not the originals hand fitted from the factory on my OB.