Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
83 SC - check operating temps for each cylinder

Continuation from this thread: Andial 2.9 Engine Refresh on a Budget


Following Tom_in_NH suggestion, I used my HF laser thermometer to check the operating temps for each cylinder in my 83 SC.

I pointed the laser dot at cylinder 4/5/6 exhaust --- actually the intake of heat exchangers, as noted by red dots on the foto. At engine operating temp, dashboard gauge, just above the first mark:

#4: ~ 180 ~ 190 F
#5: ~ 190 ~ 200 F
#6 ~ 500 F !!!!!!! --- why is cyl 6 so much hotter? I measured at least 3 times for 4/5/6 and got similar results

I was not able to reach 1/2/3, so pointed at underside of the head exchanger. Got similar results with 1 & 2 in the high 100's, and #4 much higher 350+.

Does that seem normal, what could be happening w Cyl 6?

CONTEXT: I've revived, and restarted the car, after it sat for 3+ years in my garage. It's been a few weeks now, I've started the car ~ a dozen times, and ran/idled for at least 75 min altogether. It is not running "rough" but could be smoother. Engine shakes more that I'd like to, an it could sound smoother. Changed/new: fuel, fuel filter, fuel pump, spark plugs, distro cap & rotor. Adjusted: timing and idle speed


__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-03-2023, 02:59 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Feb 2006
Location: Scottsdale, AZ
Posts: 6,752
Garage
Did you take these measurements when it was warming? Normally the area that you are aiming at temps are closer to where #6 is, 500 deg F is normal for a warmed car.

You should check the temps, at each cylinder at close intervals as the car is warming up from cold.
__________________
78’ SC 911 Targa - 3.2SS, PMO 46, M&K 2/2 1 5/8” HEADERS, 123 DIST, PORTERFIELD R4-S PADS, KR75 CAMS, REBEL RACING BUSHINGS, KONI CLASSICS
Old 06-03-2023, 04:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
Join Date: Mar 2002
Location: Philadelphia, PA
Posts: 12,616
Garage
Clarification……..

Quote:
Originally Posted by 83_Silberpfeil View Post
Continuation from this thread: Andial 2.9 Engine Refresh on a Budget


Following Tom_in_NH suggestion, I used my HF laser thermometer to check the operating temps for each cylinder in my 83 SC.

I pointed the laser dot at cylinder 4/5/6 exhaust --- actually the intake of heat exchangers, as noted by red dots on the foto. At engine operating temp, dashboard gauge, just above the first mark:

#4: ~ 180 ~ 190 F
#5: ~ 190 ~ 200 F
#6 ~ 500 F !!!!!!! --- why is cyl 6 so much hotter? I measured at least 3 times for 4/5/6 and got similar results

I was not able to reach 1/2/3, so pointed at underside of the head exchanger. Got similar results with 1 & 2 in the high 100's, and #4 much higher 350+.

Does that seem normal, what could be happening w Cyl 6?

CONTEXT: I've revived, and restarted the car, after it sat for 3+ years in my garage. It's been a few weeks now, I've started the car ~ a dozen times, and ran/idled for at least 75 min altogether. It is not running "rough" but could be smoother. Engine shakes more that I'd like to, an it could sound smoother. Changed/new: fuel, fuel filter, fuel pump, spark plugs, distro cap & rotor. Adjusted: timing and idle speed


Silber,

Are you aware that the cylinders #4-#5-#6 you have indicated with the RED dots are actually for cylinders #1-#2-#3?

Tony
Old 06-03-2023, 06:55 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 5,278
Garage
If you do have a big discrepancy, a spark plug read on a properly warm engine should tell you a story.
Lean = hot. Rich = cold(er). You may have an injector or FD tuning issue.
Further investigation would tell you - injector patterns, fuel volumes.
Alan
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-03-2023, 07:48 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
Tony - yeah, I am aware. 1/2/3 on driver side; 4/5/6 on passenger side. The red dot markers were just to illustrate where I would aim the red dot w the IR thermometer.

When I took the measurements, I could only reach 4/5/6 at the intake of HE's.
For 1/2/3 could not reach same spot.

But, after I shut the engine I looked under the car again. If I go hear the muffler exit pipe I could aim/reach 1/2/3. But I'd have to work quickly to minimize breathing in exhaust fumes directly from the pipe.


Quote:
Originally Posted by boyt911sc View Post
Silber,

Are you aware that the cylinders #4-#5-#6 you have indicated with the RED dots are actually for cylinders #1-#2-#3?

Tony
__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-03-2023, 10:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
What is a "spark plug read"; how do I do that? Do you mean aim the IR thermometer red dot at the spark plug, or the rubber wire/connector?

Injector cleaning and FD tuning/cleaning could be needed. The car sat for 3+ years in my garage.

I'm going to record another video of the engine running, post here, and ask the experts if they hear anything is off.


Quote:
Originally Posted by Alan L View Post
If you do have a big discrepancy, a spark plug read on a properly warm engine should tell you a story.
Lean = hot. Rich = cold(er). You may have an injector or FD tuning issue.
Further investigation would tell you - injector patterns, fuel volumes.
Alan
__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-03-2023, 10:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
Alan L's Avatar
 
Join Date: Apr 2006
Location: New Zealand
Posts: 5,278
Garage
Reading the plugs - checking the burn and timing issues. There are lots of threads on how to- not just on Pelican. You pull the plugs and inspect them for colour of burn and other tell tale signs.
__________________
83 SC, 82 930 (track) - Stock except for RarlyL8 race headers, RarlyL8 Zork, K27-7006, 22/28 T bars, 007 Fuel head, short 3&4 gears, NGK AFR, Greddy EBC (on the slippery slope), Wevo engine mounts, ERP rear camber adjust and mono balls, Tarret front monoball camber adjust, Elgin cams, 38mm ported heads, 964 IC. 380rwhp @ 0.8bar Apart from above, bone stock:-)
Old 06-03-2023, 11:05 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
kevbo's Avatar
 
Join Date: Sep 2018
Location: North Texas
Posts: 295
Garage
Checked out mine. Car was fully warmed up after a hot summer drive in Texas then idling on lift:

Cylinder 1 - 440
Cylinder 2 - 382
Cylinder 3 - 375
Cylinder 4 - 372
Cylinder 5 - 370
Cylinder 6 - 372

What are the normal operating temperatures?
__________________
Kevin

1986 Carrera Targa
Old 06-04-2023, 11:38 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
Join Date: Dec 2020
Location: The Swamp and NC
Posts: 450
Looks like number 1 is lean.
__________________
I'm not picking my nose..I'm porting my upper intake manifold.
Old 06-04-2023, 12:19 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
@Alan L - Thanks for clarifying. What story do these fotos of the old plugs tell?? Sorry, not the best quality fotos.

I took these fotos right after pulling old plugs out a few weeks ago. This was after the car sat in the garage for 3+ years. I've owned the car since 2010 and put ~ 6K miles on it. First time plugs have been changed under my ownership. Service records/receipts show last spark plug changed in 2002 @ 143K miles, but there is a gap in service records. At worst, the old plugs in foto are over 20 years old, with 20K miles! You can see these are Bosch when they were still actually "Made in Germany"

I'd would hate to remove the new plugs to assess. It was such a pain getting old ones removed and new ones installed. I'd rather not go through the process again, at least for a while.

Quote:
Originally Posted by Alan L View Post
Reading the plugs - checking the burn and timing issues. There are lots of threads on how to- not just on Pelican. You pull the plugs and inspect them for colour of burn and other tell tale signs.






__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-05-2023, 10:11 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registered
 
Join Date: Oct 2019
Location: Ottawa
Posts: 726
Idle vs part/full throttle.

Did a flow test at idle, part, mostly full throttle when engine was out several years ago.
Didn't want to mess too much with the cis at that time. All new injectors.

Idle: one injector had lower output than the rest.
mid/full: roughly the same for all.

I suppose you want the car on the road driving under different conditions, but even then, can you catch full load?
Once you stop, I'd guess even for a minute, all bets are off as to what you're measuring, mostly idle conditions, which may not be too relevant.

Very recently bought:
Thermo couples on the bottom are 10 ft long and good to 600F I believe.
You'd need three of the readers at once and then glue the couples to where you want.
Then drive.



https://www.amazon.ca/dp/B0BJQ95RRZ/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B0BJQ95RRZ&pd_rd_w=axdlf&content-id=amzn1.sym.43f51e91-471e-46fd-9eb7-f35b3f7790d8&pf_rd_p=43f51e91-471e-46fd-9eb7-f35b3f7790d8&pf_rd_r=ZD4CJT5AHMQA2C8SJD5V&pd_rd_wg=3odTz&pd_rd_r=ffd3aede-19c3-4b64-9c35-d4a780eb320f&s=industrial&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWwy&smid=AF6EIF5VPFPEL


https://www.amazon.ca/dp/B07NS19FN5/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B07NS19FN5&pd_rd_w=CzFmz&content-id=amzn1.sym.d8c43617-c625-45bd-a63f-ad8715c2c055&pf_rd_p=d8c43617-c625-45bd-a63f-ad8715c2c055&pf_rd_r=D7TWZ97SDAEK7N5CD9EZ&pd_rd_wg=4P26V&pd_rd_r=75c8328a-de24-4203-9cef-6da38be0916b&s=industrial&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWw
__________________
81 SC.
930/16 (us model)

Last edited by ahh911; 06-05-2023 at 11:16 AM..
Old 06-05-2023, 11:12 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Still here
 
pmax's Avatar
 
Join Date: May 2014
Location: SF Bay Area
Posts: 18,077
Garage
Looks like the "red dot" is just a laser pointer.

An IR thermal scanner gives a more complete picture.
Old 06-05-2023, 12:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
Great points. But, first things first --- get it sorted out @ idle. It is amazing what equipment is available out there now for consumers, and DIY'ers. For the time being, will just have to live w the IR gun w laser pointer and take temps @ idle.


Quote:
Originally Posted by ahh911 View Post
Idle vs part/full throttle.

Did a flow test at idle, part, mostly full throttle when engine was out several years ago.
Didn't want to mess too much with the cis at that time. All new injectors.

Idle: one injector had lower output than the rest.
mid/full: roughly the same for all.

I suppose you want the car on the road driving under different conditions, but even then, can you catch full load?
Once you stop, I'd guess even for a minute, all bets are off as to what you're measuring, mostly idle conditions, which may not be too relevant.

Very recently bought:
Thermo couples on the bottom are 10 ft long and good to 600F I believe.
You'd need three of the readers at once and then glue the couples to where you want.
Then drive.

A full IR scan would be very interesting to see. Too much money for me!


Quote:
Originally Posted by pmax View Post
Looks like the "red dot" is just a laser pointer.

An IR thermal scanner gives a more complete picture.
__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-05-2023, 03:58 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #13 (permalink)
Registered
 
Join Date: Dec 2020
Location: The Swamp and NC
Posts: 450
Your doing great.
__________________
I'm not picking my nose..I'm porting my upper intake manifold.
Old 06-05-2023, 04:03 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #14 (permalink)
Still here
 
pmax's Avatar
 
Join Date: May 2014
Location: SF Bay Area
Posts: 18,077
Garage
Quote:
Originally Posted by 83_Silberpfeil View Post
Great points. But, first things first --- get it sorted out @ idle. It is amazing what equipment is available out there now for consumers, and DIY'ers. For the time being, will just have to live w the IR gun w laser pointer and take temps @ idle.

A full IR scan would be very interesting to see. Too much money for me!
She deserves the best you can afford !
Old 06-05-2023, 04:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #15 (permalink)
PCA Member since 1988
 
Join Date: Feb 2018
Location: SW Washington State
Posts: 4,255
Garage
You have several threads going, so I'm not sure if you have run a "delivery test" yet. That will tell you if your fuel flow is the same to each cylinder. With those variations in exhaust temps, I think you're running too rich in some cylinders, and too lean in others.
__________________
1973.5 911T with RoW 1980 SC CIS stroked to 3.2, 10:1 Mahle Sport p/c's, TBC exhaust ports, M1 cams, SSI's. RSR bushings & adj spring plates, Koni Sports, 21/26mm T-bars, stock swaybars, 16x7 Fuchs w Michelin Pilot Sport A/S 3+, 205/55-16 at all 4 corners.

Cars are for driving. If you want art, get something you can hang on the wall!
Old 06-05-2023, 11:59 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #16 (permalink)
Now in Florida !
 
Join Date: Aug 2012
Location: York Beach, Maine and Anastasia Island, Florida
Posts: 406
@ 83_Silberpfeil - cylinders 3&6 usually run a bit warmer than the others. However, I think you had mentioned that the car recently sat for a period. After my SC sat for a year, in a pristine garage, mice had packed the area under the cooling shroud at cylinders 3&6.........They ran very hot!
__________________
1983 911SC Coupe Hot Rod - Platinum - Twin plugged 3.4, DC-60 cams, PMO 50's, 1 3/4 headers, Bill Rader 915 w/LSD
1976 914 2.0 Lime Green Metallic - Completely stock
Old 06-06-2023, 05:04 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #17 (permalink)
Registered
 
Join Date: Nov 2021
Location: The Far Side - Chicago
Posts: 1,241
Garage
“ A full IR scan would be very interesting to see. Too much money for me!”…

When you get all others stuff sorted, you might be able find or contact a neighborhood hvac or home inspector tech nearby that has a FLIR.
Some carry one that’s portable for use a cellphone attachment for iphone/android ($450) to locate cold/hot spots ranging -4° to +700°F.
Might even be able to locate an active rodent infestation !
Old 06-06-2023, 05:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #18 (permalink)
Registered
 
Join Date: Oct 2010
Location: SoCal
Posts: 860
Garage
Appreciate you following my progress and thanks for the compliment here!

Quote:
Originally Posted by Old H2S View Post
Your doing great.
Yes, for sure --- >>> 'can afford' <<<

Quote:
Originally Posted by pmax View Post
She deserves the best you can afford !
No fuel flow test yet. I'm sure I'll need to do that sooner or later. I would not be surprised if there are issues w proper, even fuel delivery at the moment. Recall that the car sat for 3+ years inside a garage. Once I get it on the road and drive under load, add more fuel and Techron, may be the system will "flush itself out" and get a bit better.

Quote:
Originally Posted by PeteKz View Post
You have several threads going, so I'm not sure if you have run a "delivery test" yet. That will tell you if your fuel flow is the same to each cylinder. With those variations in exhaust temps, I think you're running too rich in some cylinders, and too lean in others.
Anything is possible. There are rodents that live/hide in the ivy slope @ front of house. Do rodents have a preference for cylinders 3 & 6? Or may be there's more room in that area?

Quote:
Originally Posted by Tom_in_NH View Post
@ 83_Silberpfeil - cylinders 3&6 usually run a bit warmer than the others. However, I think you had mentioned that the car recently sat for a period. After my SC sat for a year, in a pristine garage, mice had packed the area under the cooling shroud at cylinders 3&6.........They ran very hot!
Nice instrument, thanks for sharing.

Quote:
Originally Posted by EC900 View Post
“ A full IR scan would be very interesting to see. Too much money for me!”…

When you get all others stuff sorted, you might be able find or contact a neighborhood hvac or home inspector tech nearby that has a FLIR.
Some carry one that’s portable for use a cellphone attachment for iphone/android ($450) to locate cold/hot spots ranging -4° to +700°F.
Might even be able to locate an active rodent infestation !
__________________
1983 911 SC Coupe w Sunroof, Metallic Silver --- AKA 83 Silberpfeil
Old 06-06-2023, 08:31 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #19 (permalink)
Now in Florida !
 
Join Date: Aug 2012
Location: York Beach, Maine and Anastasia Island, Florida
Posts: 406
I doubt the mice have any preference for a particular cylinder . It's the cooling fan that's blowing their bedding all the way back to 3 & 6.

__________________
1983 911SC Coupe Hot Rod - Platinum - Twin plugged 3.4, DC-60 cams, PMO 50's, 1 3/4 headers, Bill Rader 915 w/LSD
1976 914 2.0 Lime Green Metallic - Completely stock
Old 06-06-2023, 10:10 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #20 (permalink)
Reply


 


All times are GMT -8. The time now is 12:42 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.