500 miles later with my DIY 318 rebuild...

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bschubarg

bschubarg

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A car fire required me to remove the engine to replace burnt components. Complete wire harness, new ignition system, wipers to name a few. The faint of heart would of just junked the car, but of German descent, I am to stubborn and I saw an excuse to perform my alternative approach to rebuilt "Moby" as I lovingly call her for obvious reasons.

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Say hi to Moby. A 1987 Chrysler Fifth Ave. 5.2 LA with a 2.21 7.25 Rear and a lockup auto.

But this thread isn't about the car but the culmination of improvements; some are popular, some are unorthodox.

Below is a pic of the worse spark plug after 500+ miles after the rebuild.
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Spark plugs are a good tell tale sign of the health of an engine. Judging from the color I am thinking everything is working fine as far as oil control, timing and A/F ration.

I took an inexpensive approach to the rebuild.

I flex honed the standard bores and re-used the stock pistons but upgraded to Chrome moly rings. Kind of unorthodox…

I ported my 302 heads and substantially reworked the valve shrouding via combustion chamber and notching the bores. Completely orthodox...

Installed 1.88 intake and 1.6 exhaust... but I installed the 1.6 exhaust valves in the machined 1.5 exhaust seats giving a 70 degree angle and filling the combustion chamber a bit to compensate for the material I had remove in the chamber... Heresy....

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The rest of the build is you typical engine recipe that many others have performed.

Air Gap RPM Intake, 1 5/8 long tubes, Comp Cams 20-212-2 with .454 on both sides and 218 duration on both sides. Advance 4 degrees via three way chain.

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I implemented some of the Hot Rod Secrets by drilling a 1/64" hole to oil the Timing Chain. Removed a 1/2" from the intake plenum divider. Utilized an electric fuel pump and electric cooling fan. Check out the Engine Masters episode about the HP savings using a electric fan...

So the question remains....How does she run....?

The answer is complicated. This car is a DD and 95% highway. With a 2.21 rear and lockup TQ I am rewarded with 19.2 MPG. Passing cars on the freeway is an adventure. Downshifting from 3-2 rivals many modern cars and passing slower traffic(70 MPH) on North Carolina highways is exhilarating.

So it looks like a win.... right....?

Well... not exactly. Impossible to spin the tires from a stand still and 0-60 is on par with a 1976 AMC Gremlin.

So YES, Moby is doing everything I hoped to gain. Good gas mileage and great highway manners while the running temps barely break 180 degrees.

And NO, I took a wrong approach with cam selection. Current cam has 60* of overlap and a V/P of less than 100.

However, I learned a lot from the good folks here at FABO and my next build currently in progress will take advantage of the advice I received from you fine members.

Namely:
toolmanmike
rumblefish360
AJ/FormS
RustyRat
krazykuda
yellow rose
moper
nm9stheham
 
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Sorry to hear about the fire.

An AirGap intake and an open airfilter element does not jive with me.
You need a cold air intake to the most of the charge going into the engine. Probably won't help mileage that much I think.
 
From the look of that one plug and one view, you are rich at idle and even more at cruise and you are several degrees slow on timing.

What plug is it?
 
I would not call your approaches unorthodox at all, really. "Out of necessity" is the phrase I like. LOL Nice work!
 
Looks good! What was the cause of the engine fire?

About the cooling fan - what fan did you go with? A lot of folks on here lately have been troubled with electrics. Mostly they’re too small and unshrouded. (That hot rod video is unrealistic in a way that the manual fan is given a bad report because it is doing more work by moving more air vs the electric fan) You may be ok in the 5th ave, but if you hot rod it around town the coolant temp may become uncontrollable this summer.
 
I never trust electric fans. I had one die on me in my old 409 Chevy. Never again...
Your plug looks like its running rich to me.
Many of us enjoy budget builds and the updates. Good job
 
Cool. It will take more than a mild 318 to spin a tire in that heavy car with a 2 series gear. So take it for what it is... Sounds like you did alright.
 
T56MaxTorq said:
Looks good! What was the cause of the engine fire?

About the cooling fan - what fan did you go with? A lot of folks on here lately have been troubled with electrics. Mostly they’re too small and unshrouded. (That hot rod video is unrealistic in a way that the manual fan is given a bad report because it is doing more work by moving more air vs the electric fan) You may be ok in the 5th ave, but if you hot rod it around town the coolant temp may become uncontrollable this summer.
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What caused the engine fire...short answer is stupidity. I left a gas soak paper towel in the engine bay and when I closed the hood and took the car out for a test drive the paper towel lodged itself around the distributor and poof. By the time I put out the fire the entire engine bay was toasted.

As far as the cooling fan... It is pulling air and is inside a fan shroud. Built by Hayes and draws 1200 cfm of air is does the job. When in a traffic jam during a hot day the highest temp I recorded was 240* F.
 
My fire was the throttle cable rubbing the wiring harness, not the only one either.
 
halifaxhops said:
My fire was the throttle cable rubbing the wiring harness, not the only one either.
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Had that happen too at the Mopar Nationals on Brice Road. It's really concerning when your entire car goes black. You get out and look in the hood scoop and see fire. Not fun!
 
Do chrome moly rings really exist?

Some 30 years ago I guess (man time flies) when build my first 318, I took all my parts to the machine shop and I had them supply all the parts. I told him I wanted chrome moly rings, he said I’d been reading too many hotrod magazines.
Said I could have chrome rings, or moly rings, but not both.
 
yellow rose said:
From the look of that one plug and one view, you are rich at idle and even more at cruise and you are several degrees slow on timing.

What plug is it?
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You determined rich at idle and retarded timing by just that pic of the #4 plug...? What does my future hold...? :)
 
bschubarg said:
You determined rich at idle and retarded timing by just that pic of the #4 plug...? What does my future hold...? :)
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Sure did. Your future is giving up power and drivability until you fix it.

Reading plugs isn't that hard. You should learn to do it. While it was all the rage in the late 90's and all through the 2000's tell people who knew how to read plugs how stupid we were because we didn't use O2 sensors and all that bullshit (which we had on they dyno BTW so I used them) and in the last few days I've seen no less than 3 articles on how important reading spark plugs is.

O2's can fib. I trust a plug reading long before anything that comes off a computer.

So yes, you timing is slow and you are rich at idle and cruise. And that's without knowing the brand of plug. At least it isn't a black shelled plug.
 
Plus, reading a plug gives you cylinder specific insight. An 02 sensor gives you an average. Every cylinder is a little bit different.
 
I mentioned in the last post I thought the jets were way too big and a stiffer secondary spring would help. I would drop it back down to factory jetting and tune the ignition first then play with the carb. What have you done with the distributor? Is it still have the stock advance curve in it?
 
Thank you Yellow Rose, Gliderrider06 and T56MaxTorque. You are the very examples as why I defer to your good judgments.
Today I will replace the lightest spring that is currently installed to a stiffer one. I will also go back to the default jets as advised.

I did not change the Distributor springs..... yet....

Thanks again guys for having my back....
 
bschubarg said:
You determined rich at idle and retarded timing by just that pic of the #4 plug...? What does my future hold...? :)
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You can't read a plug without cutting thread "canister" off and knowing fuel type AND how the engine was last run or "tested". Get a wideband learn how it works and what it tells you. Yes they can lie but with your mild combo you probably won't run into that. It is amazing what you can "see" with a wideband. J.Rob
 
An O2 sensor is the ONLY way to get an even close approximation of what the actual fuel/air ratio is. Reading plugs used to work OK with leaded gas and assumed the heat range was cool enough. Modern fuel burns a lot cleaner and OEMs notoriously spec a hotter than necessary plug for daily driver use. This makes sure the plug is always clean in stop and co running and frequent cold starts. Great to prevent misfire related emissions. Without a wideband I have had the best luck by first returning the carb to the factory jetting and configuration, paying especially close attention to float levels. Then dialing in my timing. Then and only then do I start messing with the PRIMARY jets (with secondaries disabled if possible). On aftermarket carbs, I start by going leaner 2 numbers at a time until is surges, bogs or becomes noticeably slower. With factory carbs I generally start by going richer. At my 2800 foot altitude aftermarket Holleys are a bit rich out of the box, Edelbrocks are close and OEM Quadrajets can be anywhere.
 
yellow rose said:
Sure did. Your future is giving up power and drivability until you fix it.

Reading plugs isn't that hard. You should learn to do it. While it was all the rage in the late 90's and all through the 2000's tell people who knew how to read plugs how stupid we were because we didn't use O2 sensors and all that bullshit (which we had on they dyno BTW so I used them) and in the last few days I've seen no less than 3 articles on how important reading spark plugs is.

O2's can fib. I trust a plug reading long before anything that comes off a computer.

So yes, you timing is slow and you are rich at idle and cruise. And that's without knowing the brand of plug. At least it isn't a black shelled plug.
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I took your advice Yellow and after some internet research, you are absolutely correct...I never paid attention to the fire ring or threads; just the porcelain and electrode....I'll post another pic after I'm finished so you can tell me if I am in the ballpark...

You should think about starting a business reading palms... ;)
 
bschubarg said:
Thank you Yellow Rose, Gliderrider06 and T56MaxTorque. You are the very examples as why I defer to your good judgments.
Today I will replace the lightest spring that is currently installed to a stiffer one. I will also go back to the default jets as advised.

I did not change the Distributor springs..... yet....

Thanks again guys for having my back....
Click to expand...
This is number one ,in my book sir....
 
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