Author Topic: 383 Stroker trouble - Too hot?  (Read 2423 times)

Offline TIREKIKR

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383 Stroker trouble - Too hot?
« on: December 04, 2021, 01:51:04 PM »
Drove my newly installed 383 Stroker 50 miles to a dyno shop to have it tuned.  No touble getting there, but the drive back home a week later was tons of fun, until I saw steam out the rearview mirror.  Shut her down, way too hot (I know...the stupid gauge was still at 120), boiling gas in the carb and couldn't touch the oil filler cap for 3 hours.  Towed it home.  Started up the next day like nothing happened, but have been unwilling to drive it until I figure out the problem.

Heat tabs on the back of the heads are both melted.  I'm worried he somehow fried my engine.  Just checked cylinder compression, and everything's between 100 & 94.  That's it.

He mentioned moving the timing way out to 32.   From what I've read, I wonder if he set the timing too far in advance and early detonation in the cylinders cooked it. 

I have good water flow.  Haven't yet checked the timing.  Long-block was built by Phoenix Engines. 

Bore= 4.030
Stroke= 3.750
Compression Ratio= 11.1

I've got to keep this simple.  I don't like the whopping cam that's in there (Int-508, Exh-532, Dur@0.5: 244-254, Lobe 112), so the top end needs to come off anyway.  Would appreciate input on what else I need to do before taking it apart, and what to check after the heads are off.  If the rings are shot, maybe I'll go to an LS.  But gotta stop spending $$.   Thanks in advance!
Rick

« Last Edit: December 04, 2021, 01:54:39 PM by TIREKIKR »
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Offline Mike81K10

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Re: 383 Stroker trouble - Too hot?
« Reply #1 on: December 04, 2021, 07:47:56 PM »
Determine if the shop that did the dyno did any damage prior to tearing it apart or they won't be responsible. Before the engine is ran hard it should be broken in first. Read up on any warrantee information since it is new.
« Last Edit: December 04, 2021, 09:42:17 PM by Mike81K10 »
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Offline VileZambonie

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Re: 383 Stroker trouble - Too hot?
« Reply #2 on: December 04, 2021, 08:20:11 PM »
Quote
Drove my newly installed 383 Stroker 50 miles to a dyno shop to have it tuned.

This is where you went wrong. In 50 miles you could have dialed in your truck on the STREET. There is absolutely no need for a dyno tune on an NA carbureted SBC. Sure a dyno offers you the ability to dial in timing, boost, A/F mixtures so you can get a baseline setting in your programming but you're talking HEI, carburetor setup which requires you to test n tune and the street provides you the REAL dyno.

So what did they tune? You drove there fine and drove home on a flatbed with overheating so it sounds like they over-advanced the ignition timing and you probably have an inadequate cooling system, fuel quality, spark plug heat range and why did you go with 11:1 compression ratio and what fuel are you running? What heads? What T-stat, fans, etc. Need ALL of your specs to really offer you any remedy outside of guessing.


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Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #3 on: December 04, 2021, 08:31:19 PM »
Thanks for the reply Mike81.  Unfortunately, I didn't get anywhere after a couple calls to the shop.  I won't name them here, but he's been around for a long time and claimed nothing went wrong under his care.  It was a hot day when the work was done, but still shouldn't have cooked.  Break-in instructions were followed to the letter.  No problems at all for about 60 easy sub-4000rpm miles to the shop. I wanted the carb adjusted (with new jets), timing and kick-down adjusted.  Cooked on the way back.  Even if it is as easy as a thermostat, does it not make sense to go ahead and remove the heads to look for damage since it got hot enough to melt the heat tabs?
- Rick

Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #4 on: December 04, 2021, 08:56:07 PM »
Hey VileZambonie.  I'm old enough to know better and to have done a "street" tune myself.  I've got the tools, just got lazy.  You're right...that's exactly where it went wrong.  Bought the truck unfinished with this engine in it, so the 11.1 was the builder's idea for a high-revving track-style truck.  Let me tell you what I know.... hope you can look at the ingredients and shed a little light on what's next for me.  Just dawned on me that it was the first time I ran the Vintage AC, if that could have played a part...hmmm.

Carb:  Holley 750CFM with vacuum secondary
Intake:  Airgap
Distributor:  MSD HEI Adv Kit
Water pump: Long
Cam:  Speedpro 510+ Hydraulic
Pistons:  SpeedPro Dome Hypereutectic
Heads: Dart, Intake 202, Exhaust 160
Plugs:  AR3932
Gas:  Premium Unleaded (92 octane) from Costco
Full Headers with 3" full dual exhaust / Dynaflow 50's
Radiator:  4-core aluminum with dual electric fans (working)
Thermostat:  Dunno...came with build and not specified
Billet Specialties FM2113PC Serpentine Conversion Kit
Vintage AC, AT, PS

He re-jetted the carb, since I live at 8400 feet and primaries/secondaries were 72/75.  Though I gave him the specific engine-builder instructions that say "don't exceed 6,000rpms", the dyno sheet shows he took it to 6,086 where he got max HP at 366.4 to the wheels.  The build papers also warned not to take the overall timing past 30, and he mentioned (after talking of the problem) taking it to 32 and backing it down from there.  So, here I am and not taking it back to the guy.  What's next?
« Last Edit: December 04, 2021, 09:18:04 PM by TIREKIKR »
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Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #5 on: December 04, 2021, 09:04:13 PM »
Did a compression test on the cylinders today.  First pass numbers with the engine ice cold are on the left side.  Right side shows compression after I squirted some Sta-Bil into the cylinder.  I'd thought this'd indicate rings are bad, but it's pretty consistent.  Not sure if this lends aid to the diagnosis, but sharing with you what I have.  Appreciate any suggestions on what to do next. - Rick
« Last Edit: December 04, 2021, 09:51:02 PM by TIREKIKR »
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Offline JohnnyPopper

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Re: 383 Stroker trouble - Too hot?
« Reply #6 on: December 04, 2021, 09:30:27 PM »
Wow, wonder how this turns out... ???
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Offline VileZambonie

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Re: 383 Stroker trouble - Too hot?
« Reply #7 on: December 05, 2021, 12:39:44 PM »
You may want to consider running better fuel but first, check to see what t-stat is in there and check the timing yourself to see where it's at. Record your results and drive it. See if it is pinging.
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Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #8 on: December 05, 2021, 03:22:27 PM »
Gotcha.  I'll order a new thermostat, and test the old one. Will let this forum know where that takes it...
- Rick

Offline joel1847

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Re: 383 Stroker trouble - Too hot?
« Reply #9 on: December 15, 2021, 08:25:13 AM »
  Something isn''t right.  In order for their to be steam coming out of the engine and the temp gauge reads normal, you would have had to be low on water going to the dyno test, or low on water after the dyno test.  You said you had good water flow and had done a street tune so you should have gotten any air pockets out of the system prior to the dyno test.  That only leaves the dyno guy cooked it or got it warm and didn't bother to check the fluid levels during or after his tests.  Double check your thermostat opening temperature, water pump flow, and your temp gauge-a candy or meat thermometer in the radiator once at temperature gets you in the ballpark.  Pull the thermostat and put it in a pan of hot water and see if it opens.  Water boils at 212 degrees give or take, so this will at least let you know if the thermostat is opening or not.  Candy or meat thermometer will get you closer to the actual temp at which the T stat opens.

You said you didn't like the cam that was in it, so this is a good opportunity to fix that.  Get a good gasket kit, basic rebuild kit with rings and bearings, and your cam kit.  Check your intake, heads and block surfaces to make sure nothing is warped and put it all back together. 

Hopefully you can get the dyno guy to accept some responsibility and you won't have to eat the entire cost.
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Offline Mr Diesel

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Re: 383 Stroker trouble - Too hot?
« Reply #10 on: December 15, 2021, 10:21:53 AM »
Just dawned on me that it was the first time I ran the Vintage AC, if that could have played a part...hmmm.

Probably want to look into this a little more before blaming dyno guys. You also mentioned it was hot that day. If you did not have adequate cooling capability, running the ac could have easily pushed the cooling system beyond  capacity on the way home.
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Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #11 on: December 15, 2021, 10:51:09 AM »
Just received a new thermostat and temp sending unit, so will start there this weekend.  Not accusing anyone, just laying out the events leading up to the problem.  Will focus on getting the cooling system first.  Seems the general consensus is to verify  it's performing right with flow and temps.  Not changing timing or anything else yet.

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Offline Mike81K10

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Re: 383 Stroker trouble - Too hot?
« Reply #12 on: December 15, 2021, 04:20:10 PM »
As joel1847 was referring to! Prior to installing a thermostat put it in a small pot of water and heat up the water. You can use a thermometer to check the temperature of the water when the thermostat opens. This way you know it is working properly prior to installation.
« Last Edit: December 15, 2021, 04:22:36 PM by Mike81K10 »
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Offline TIREKIKR

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Re: 383 Stroker trouble - Too hot?
« Reply #13 on: December 15, 2021, 05:17:32 PM »
Joel & Mike.  Great advice.  I'll have an update this weekend...
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Offline VileZambonie

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Re: 383 Stroker trouble - Too hot?
« Reply #14 on: December 15, 2021, 05:45:21 PM »
What temperature t-stat are you running?
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