1996 - 318 Engine Rebuild - guidance request

make sure you follow the ring manufacturer 's directions. You don't want to install the rings upside down. And you want to adjust the end gaps properly, and stagger the gaps.

Rustycowl69 said:

make sure you follow the ring manufacturer 's directions. You don't want to install the rings upside down. And you want to adjust the end gaps properly, and stagger the gaps.

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hmmm .. what do you mean adjust the end gaps, exactly ? I certain can't make them any bigger, and I'm not sure how, if there even is a way, to check them AFTER I've inserted the piston with them.

The only way I know is to put the ring inside the cylinder with out the piston and then measure the gap. I've done that with the 0.060 rings I've bought, and they are at 0.020 gap.

The spec, at least according to the manual I have, allows for them to be up to 0.030 gap. ( The steel rings, not the oil ring )

Is that sufficient ?

I also didn't know you could install rings upside down. Glad you told me that.

I also have a buddy who will be there helping me when I actually do this.

You can open the gaps more by filing the edge. You basically just have to compress the ring to check the gap whether by inserting the piston halfway into the bore or using a compressor tool

squarethumps said:

hmmm .. what do you mean adjust the end gaps, exactly ? I certain can't make them any bigger, and I'm not sure how, if there even is a way, to check them AFTER I've inserted the piston with them.

The only way I know is to put the ring inside the cylinder with out the piston and then measure the gap. I've done that with the 0.060 rings I've bought, and they are at 0.020 gap.

The spec, at least according to the manual I have, allows for them to be up to 0.030 gap. ( The steel rings, not the oil ring )

Is that sufficient ?

I also didn't know you could install rings upside down. Glad you told me that.

I also have a buddy who will be there helping me when I actually do this.

Click to expand...

Too little gap, and if the ends ever butt together, you'll break a ring or break a piston ring land. Too much gap, and you are losing compression and power, and possibly oil control. I haven't built an engine in years, but there used to be a rule of thumb for minimum end gap. I THINK it was like 0.004" for every inch of bore diameter. So, if you have a 4.00" bore, it would be 4.00 X 0.004 = 0.016". But you have to remember that is the MINIMUM, and it's for a perfectly straight, perfectly round bore, honed with a torque plate. Anything less than perfect, it would require more gap. I'm sure if you Google it you can confirm the "rule of thumb" for yourself.

Rustycowl69 said:

Too little gap, and if the ends ever butt together, you'll break a ring or break a piston ring land. Too much gap, and you are losing compression and power, and possibly oil control. I haven't built an engine in years, but there used to be a rule of thumb for minimum end gap. I THINK it was like 0.004" for every inch of bore diameter. So, if you have a 4.00" bore, it would be 4.00 X 0.004 = 0.016". But you have to remember that is the MINIMUM, and it's for a perfectly straight, perfectly round bore, honed with a torque plate. Anything less than perfect, it would require more gap. I'm sure if you Google it you can confirm the "rule of thumb" for yourself.

Click to expand...

OK. I mistyped and wasn't clear. I know you can file the ends to make the gap bigger, but I was confused thinking somehow you could close the gap.

I am sure mine is less than perfect, and it was bored 0.060 over so I'd already be at like 3.97 bore diameter in a less than perfect round.

I think that means that the 0.020 gap that I have would be just about right.


Any opinion or worry about the possibility of the heads being milled down so far that the flat top pistons with no valve relief would be a problem ? The previous pistons were the 4 relief variety, which, as I understand, is only to make assembly easier ?

OK, so my buddy came over and helped me take the old rods and put on new pistons and wrist pins.

Even though he said "it's ok", I'm very concerned because as the wrist pins were sliding in to the lower hole of the piston, they all ( except one ) scored the hole a little bit. Not much and they still move easily. There were definitely some metal flakes on the ends of the pins that I was able to clean up, but I need to know from you experts if this is really OK ?

I was not happy about it at all, and I'm really concerned that it will cause a problem in the future.

Thanks for the input.

still no opinions on this ?

just an update :

I put together the entire short block and have turned the engine by hand numerous times with a wrench. Everything feels very good. Very smooth, not loose, but just nice and firm.

Then I started on the heads, and since I was able to see light by looking up through the several of the exhaust ports, I decided to take them to a machine shop for professional preparing. 175.00$ --- I thought it was a good deal.

4 trips to 2 different junk yards later, and I _think_ I've finally found a solid head for replacing the one of mine that was cracked in two places. This would explain the pressure in the oil chamber, and the oil being pushed out of every gasket.

I'm waiting for the machine shop to call me back to confirm that this latest head I've taken them is actually viable to use.

Who knows, perhaps I'll be able to put the heads on this weekend !

when I used to do heads, I would vacuum check the ports to be certain the valves are sealing properly. Nowadays they cut the seats with form tools. If the machinist is cutting corners, he might not cut the seat concentric with the guide, giving a less than ideal seal. This will result in poor vacuum, etc. I used to have to redo freshly rebuilt(by others) heads frequently.

Here's some pictures of the finished install. I must be out of my mind. I cleaned everything, sandblasted the brackets, intake, etc, and then even clearcoated the intake and aluminum brackets, painted everything else. That A/C unit and alternator are the only things ( right on top of course ) that were just kind of wiped down with a rag.

It runs fantastic -- WHEN IT'S COLD !!!!! As soon as the engine temperature warms up, it will sit and idle fine, but if I step on the gas even a little bit and then let go, it will throttle down all the way to stall. It was throwing the P1391 code, which didn't make sense since I replaced both the cranksensor and the cam shaft sensor, and the temperature sensor for the PCM. ( and for the gauge but that doesn't matter ). I have a brand new cat and both O2 sensors.

I've been fighting this for like 2 weeks now, and basically I've concluded that the PCM must be reprogrammed to match the cam. When I originally ordered the cam, the guy from Summit Racing swore up and down that I could install this cam with no need to do any PCM reflashing. I just contacted them again, and this time the tech guy said that ya, it needs to be reprogrammed. Great. I'm just agitated because if I'd known that, I wouldn't have fought and replaced the other sensors. So now I'm looking for a local shop that knows what they are doing with this stuff so I can give them the cam specs and have them reflash the PCM.

Also - some of you may know this - it is of utmost importance to make sure that your timing gears are set correctly. If you buy a performance timing chain, it is important to not only ensure that the proper dots are lined up, but ALSO to make sure that the crankshaft is locked to the proper keyway. If it is not, certain bad things can happen. For instance, bending every single exhaust valve. Even though this is supposed to be a non-interference motor, the extra duration of the cam probably contributed. It could also bend 8 of the push rods as well. Ask me how I learned these things.

Please provide a link to the cam you've chosen

https://www.summitracing.com/parts/CCA-20-744-9

This is it.

Unfortunately that will need tuning yes. LSA is slightly tighter than factory and it features slightly more duration.

I would suggest ryan at frptuning.com if you're anywhere near Houston. Otherwise you can get an email tune via sct through Marty Fletcher from the
"Dodge & jeep 5.2 & 5.9 magnum v8 performance & tips" Facebook group. Lastly there's Hemifever for an email tune. Do not even consider PIE. I wouldn't do local shops either because the majority aren't at all familiar with JTEC and even hemifever will be better

I would suggest ryan at frptuning.com if you're anywhere near Houston. Otherwise you can get an email tune via sct through Marty Fletcher from the
"Dodge & jeep 5.2 & 5.9 magnum v8 performance & tips" Facebook group. Lastly there's Hemifever for an email tune. Do not even consider PIE. I wouldn't do local shops either because the majority aren't at all familiar with JTEC and even hemifever will be better

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I'm sorry dapepper, you said a lot of words there that I don't understand. "email tune via sct" ? I don't think I have the tools to do a reflash myself ? what is it a file of some sort that can be e-mailed to me ? I'm assuming it's much like a BIOS flash on a router or other computer.

I'm in the Pittsburgh area.

I'll try to join that group though and see if anyone can help too.

Basically you buy a handheld programmer and somebody capable of writing a new program for the vehicles computer will email it to you. You load it into the handheld and then plug the handheld into the truck and follow the on-screen directions. It's easy. Only part you'll maybe run into troubles is loading the file onto the handheld and if you do just call sct technical support and they'll pretty much do it for you lol.

I see. That does sound easy. I will see about the handheld programming tool.

I appreciate the response and help.