4.7L V8 engine rebuild

Automotive
#1

Im in the process of rebuilding the V8 out of my 99 Grand Cherokee and was encouraged to share my progress so here goes.

The impetus for all this was a top end noise from what I can only assume was collapsed lash adjusters as well as a mysterious loss of coolant.

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After pulling the heads I took them to the parts washer at DMS and cleaned 180k miles of abuse off of them. The lash adjusters operated off of hydraulic pressure from the oil pump but there was so much grunge built up in them that hardly any pressure was being made.

And as for the coolant loss, upon examining the clean heads I found a nice long crack between cylinders 1 and 3 going from the water jacked into the area where the head gasket was oddly discollored. I can only assume the coolant was making its way into one of both of these cylinders based on my sweet smelling exhaust.

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So I managed to find a 4.7 in a junkyard with heads that look to be brand new and was able to pick them up for $100 total

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With my head situation solved, it was time to send the block to be prepped and overbored .030 cuz, you know, that extra .07L is going to make the difference. (It was the same price regardless so that’s the number I landed on) And with the block back and all the parts in I set out to reassemble.

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Platigauging my crank mains

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New pistons hooked to the old connecting rods

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Learning how to used a piston ring compressor was fun… but I ended up getting all 8 installed and hooked to the crank.

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Next up is grinding the valves and the installing the heads. Stay tuned for more.

14 Likes
#2

Kewl Stuff! :slight_smile:

Don’t forget to make a post on the current #public-relations:show-and-tell thread - including the blurbs about which tools you used at the Space and all… :slight_smile:

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#4

I wouldn’t even know where to begin with this stuff. I look at this picture and know I’d.m never get it back together again ever, much less on time to use the car again.

How’d you learn to do all that or have you always worked with cars?

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#5

This is my first time rebuilding an engine. I’ve got a factory service manual and an internet connection. Those two things coupled with a general mechanical inclination will get you through just about anything on a vehicle.

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#6

Is this the engine located in storage in the workshop?

#7

Yes it is. I hope to have it completed this week

#8

Factory service manuals are the way to go - the “other” two popular repair books(chiltons and haynes) are good for chocking a door open or for basic “one size fits all” basic information.

Looks great!

3 Likes
#9

Snaps,

Will you (hope so) be installing new chains. guides and tensioners?

#10

Yes, that’s was another issue. The chains had stretched to the point that the tensioners had racheted all the way out and were no longer pulling the slack out of the chain. The chains look to be original and there were deep grooves cut in all the guides

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#11

[quote=“snaps, post:1, topic:18962”]
And as for the coolant loss, upon examining the clean heads I found a nice long crack between cylinders 1 and 3 going from the water jacked into the area where the head gasket was oddly discollored. I can only assume the coolant was making its way into one of both of these cylinders based on my sweet smelling exhaust.[/quote]

Any idea what might have been the cause of this crack?

A mechanic once told me the 4.7 was a good engine, but watch for overheating.

[quote=“snaps, post:1, topic:18962”]
So I managed to find a 4.7 in a junkyard with heads that look to be brand new and was able to pick them up for $100 total[/quote]

You were lucky to find those. Cash for Clunkers took a lot of them off the road.

#12

My guess is either it was overheated at some point or one of the previous owners replaced a head gasket and didn’t follow the correct procedure for torquing the head bolts.

The heads came off an engine that I can almost guarantee had the top end rebuilt. There was zero build up on any of the domes and all the intake gaskets and head gaskets looked brand new. It was junked because whoever rebuilt it sheared off the cam sprocket pin (probably on first start up) and lost all timing. Amazingly enough non of the valves were damaged.

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#13

You lucked out on the cylinder heads. City Motor won’t give you core price for a cracked one. However cylinder heads international would charge you one price to rebuild it.

#14

Holy crap those manuals are expensive. May have to go down this road myself though. Literally today my engine started to splutter and the tachyometer waver when I started it up.

#15

Factory service manuals are never $10 or $20.

Prices vary & depending on vehicle you may find one on ebay, half price books, classifides on aenthusiast website for the vehicle, and some publishers.
Robert Bentley publishers makes factory servive manuals for VW, Porsche, Audi, BMW, and others.
They also have an online tech service and print various enthusiast’s books.

1 Like
#16

If you can find them.

I had to settle for a PDF version. At least I can search it.

Personally not too crazy about electronic copies.

I find reading the manuals times entertaining and always insightful.

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#17

Did you decide of you are going to get new valves or try cleaning/recovering a working set from what you have?

#18

Agvet,
I’d suggest you determine what’s going on with your car first and go from there.

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#19

I was able to get a full set of “probably not too worn” but then I found a full set of brand new enginetech valves for $90 and figured that’s a small price to pay for not having to do it again. (This is the 3rd or 4th time I’ve used “small price to pay” so at this point the price is fairly large but it rather not have to re rebuild it when it shits the bed after reusing old parts)[quote=“ejclxxi, post:17, topic:18962, full:true”]
Did you decide of you are going to get new valves or try cleaning/recovering a working set from what you have?
[/quote]

1 Like
#20

ROFL
Last time I bought a Bentley manual (probably ca. 2005, for the A4 VWs) they had stopped publishing dead-trees. So they had concocted this gawd-awful electronic version that makes a PDF seem like a dream. It mimics Snap-on Online (ShopKey), if you’ve ever been lucky enough to interface with that. I still have it. I even updated in 2012. Same gawd-awful interface, but with more current models. I even have a Windows XP VM for it to run on, cause it won’t run on anything newer (well, it will, in “compatibility mode”, hence the VM). Horrid product. Happy to see it appears someone somewhere saw the error of their ways and started publishing again. Their manuals truly are the best. Their software is shyte (just like all the other online manuals I’ve used).

1 Like
#21

new valves along with other ancillary parts is cheap insurance on not having to do the same job a 2nd or 3rd time or worse.
I my old car days - I couldn’t fathom folks that would go to a salvage yard to “save money” for things like wiper blades, spark plug wires, water pumps, etc…
I understand being on a budget for car repair but making wise choices will save time and money in the long run.

2 Likes