I had never pulled an engine before but I had to get the straight six in my '84 out enough to remove the oil pan because it was making this strange nocking sound.
Turned out the crankshaft dropped a bolt and I didn't stop running the engine soon enough so...

I have a replacement crankshaft & bearings on hand.

Since I have the whole engine out and pulled apart, I figure it was a good time to give it some TLC.
Problem is, I don't know what to I should do.
So I'm asking you experienced folks for your recommendations on what to do while the heart of the beast is out for surgery.
I have two basic questions.

1. I figure this would be a good time to take it to a machine shop so what services should I have performed and what do you deem a reasonable price for them?
(I'm in San Antonio. Got any particular recommendations on where to take it?)

2. What else should I do while the engine is apart?
I'm far more interested in efficiency rather just than more power.


Bonus questions:
Since the engine is detached from the transmission, should I do anything in particular to it while I have easy access?

Any other particular recommendations are welcome as well.

Thanks yall!

 

What transmission do you have? If it's a automatic, you must replace the seal behind the torque convertor or it will leak after you put it all back together. Replace it just before you put the engine in, the torque convertor hangs on the seal and after awhile, it ruins the seal. If you do this, make sure you push and turn, push and turn, push and turn many times the torque convertor to make sure it engages fully into all the different splined shafts of the transmission. If you have a manual trans, you probably need to re-surface the flywheel and put a new clutch in it unless the one in it looks perfect.

If you are going to take the engine to a machine shop, they will measure it up and make recommendations. If they measure the cylinder bores and they are worn, then they will want to bore the cylinders and then you will need new pistons, and they will have to put the new pistons on the old rods. This will hit your pocketbook hard. You will also need the cylinder head gone through, they will re-grind the valves and the seats, and install new valve seals. Along with a gasket set, if you re-aasemble the engine yourself and they do all the above, I expect you will have close to $1200-$1500 in it. If they re-assemble it, it will be more of course. But you will have a new engine that will last afterward.

 

It sounds like it spun a main bearing and if so then either have your crank turned if not too bad or replace it like you have now.
Now the block's main bearings may not, I would bet on it and I don't bet, be in line with each other so you cant just drop the new crank with bearings and not have any issues.
With that say the block will need to be line honed to get them back inline.

To do the above the motor needs to be taken fully apart to do that and cleaned before put on their equipment.
Also when taken apart they would measure the piston bores & pistons to see if they can be reused. If not then you would need new pistons and the block bored over size to fit them.
Rods would also need to be checked before they would be reused.

Then you have the head. It would have to be taken apart to check the valves, springs, seats and guides as you don't want to put a wore out head on a new block.

Now prices for this work is different all over the USA so you need to check with shops in your area to see what they will charge.
If you can get 2 or 3 prices it would be great. Then check what a crate motor will run you as you may find it to be cheaper.

Now that the motor is out what to do if anything to the trany? You did not tell use and it's not in a signature what trany you have?
If a stick replace the clutch / pressure plate / throw out bearing and maybe the pilot bushing / bearing. If it was jumping out of gear then it needs a rebuild.
Auto, if was working good then nothing till maybe it is running again and when warm change the fluid & filter. If it was having issues shifting or going into gear maybe check with a rebuilder to see what they have to say but it would be nothing to pull it out and take it to the rebuilder for a rebuild.

See this is what I call the snowball effect rolling down hill....it gets bigger as to rolls along.
Motor short block rebuild to head rebuild to maybe trany rebuild.
Heck it is only money LOL
Dave ----

 

Stock pistons are the weak link of the 300 I'd say. At least get a set of sealed power h519p pistons. They work great, are cheap, and can handle a fair amount of power. E-229k rings worked well on those pistons for me. You may want to bore it 30 depending on wear. If you're pulling the crank get a fel pro seal kit and change all the seals you can.

 

I have not seen or heard that. If you have spark knock then any motor will have a weak piston as it gets a hole burned thru it.
For a stock rebuild I done see needing anything more than the stock cast type pistons.

If you are running power adders, blower or turbo or spray for racing then yes on the forged pistons and you better be going with forged rods too or be ready to catch them when they leave the motor!
Dave ----

 

Many people on the forum here have torn apart their 300s to find broken piston skirts or cracked pistons, you name it.

Read through this thread or at least posts 1,9,25 before using stock pistons again.

I also had a 300 factory bought by my grandfather, never opened, about 50k miles. I put on a carb, intake and exhaust. Within a few months compression went down on a cylinder and the cylinder is scratched all over but I haven't looked into it.

At a minimum sealed power hypereutectics are cheap and work well. My 300 is quite modified and I have driven them for over a year everyday and they have held up perfect. I won't run stock 300 pistons in anything again.

 

I guess you could have a bad stock piston from the factory but look how many are made, how many are installed in motors, and look at how many have had issue.
The percentage has got to be pretty low for the number made to the number of failed pistons.

The reasons most of the pistons go bad is timing that is off to cause spark knock.
You do not need to hear pinging for it to happen and it will just keep hammering the top of the piston till it breaks.
Running the motor lean just helps spark knock to happen.

Now what you are saying of the stock piston I have heard of the hypereutectics pistons.
If I was rebuilding a motor other than back to stock I would go forged and live with piston skirt knock / slap till up to temp.

If you look into why any piston goes bad it will be spark knock & running lean, be it a I4, I6 a V6 or V8, unheard spark knock killed the piston.
So don't say it was a junk stock piston and never run one. If any motor is tuned right and serviced as needed it will last for almost ever.

You know what is nice .... we can all have our opinions.
Dave ----

 

I do agree Dave. Massive amounts of 300s have been made and are tough as nails. UPS trucks to ski lifts to f600s the inline stands strong. In a stock motor with a proper tune the 300 will not die even with the harshest abuse. I've driven one for 20 min down the highway bucking with no oil and didn't scratch the rod bearings.

OP wants to know what he should change while his 300 is apart for efficiency and reliability purposes. The only part I can think of is pistons, maybe oil pump if the milage is high. Many people seems to break skirts or crack them under regular use. Much better hypereutectics can be had for 79$ or 127$ at 0.030 over. I'd rather build the engine with better pistons and not worry about blowing a piston 20hrs from home because the timing is a bit off....

I've blown a stock piston or ring just after a few speed parts. Now I'm 21 with a lift kit, 35inch tires, front locker, manual trans, and a right foot like a boat anchor in Canadian winters. Ran it out of coolant and hit 260* the first time it ran, overheats in summer traffic, diesels on shutdown, spin it to 5500 dozens of times a day with stock rod/head/main bolts. I can't break it no matter what new trick I try.

I don't speak for everyone and I'm no engineer, but I swear by a 300 with better pistons and a proper tune.

 

I believe the factory rods for all 300s are forged although I may be wrong...