Club Cobra GasN Exhaust  

Go Back   Club Cobra > Engine Building, Tuning, and Induction > Small Block Talk

MMG Superformance
Nevada Classics
MMG Superformance
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
MMG Superformance
Advertise at CC
Banner Ad Rates
MMG Superformance
Keith Craft Racing
April 2024
S M T W T F S
  1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30        

Kirkham Motorsports

Like Tree8Likes

Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #1 (permalink)  
Old 02-09-2024, 08:43 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2022
Cobra Make, Engine:
Posts: 89
Not Ranked     
Default Help With my crate 427 Engine Won't Start

Frustrated
I built a test stand so I could test and run my Ford 427 crate engine before the install in my SF. I recently had to replace both head gaskets because I noticed some oil seepage form the rear of both heads. Then to my dismay my oil was a bright beige in color, WOWE is me. I got the usual from the Ford performance deptÖ ďnever seen that problem in 20 yearsĒ I at least got a set of gaskets from them because itís still under warranty.

At first, I thought the engine oil dye I used may have caused the oil color change but after letting some oil test samples set on my counter for a week, I can see some water separation at the top.

After taking my utmost time in changing out the gaskets and adjusting the rocker lash, and re assembling I cannot get this thing to start, it does the typical backfire and flame through the carburetor (timing was not off 180). I quadrupole checked TDC and alignment on #1 cylinder with the rotor cap, plugs are wet, and all valves are opening and closing, plus checked for spark, everything good.

I talked to an engine builder buddy from work and we both are now thinking it might be the Progression electronic distributor/ignition as a possible cause. I talked to them, but they donít feel its their problem, but I can send it back for them to check.

This just doesnít make sense. I dressed the engine up from the crate long block and it started right up, and I ran it many times for about 2 months. I was so impressed it would start with 2 pumps within 1 crank, better than fuel injection, so I thought.

Wires were installed as a unit with the cap when assembling so itís not a wire mix up problem. Iím thinking of sending the ignition/dist. back to see if they can check it, and possibly installing a mechanical type for trouble shooting or eliminating this variable.
Not sure what else to try.

David
Reply With Quote
  #2 (permalink)  
Old 02-09-2024, 09:01 AM
eschaider's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2006
Location: Gilroy, CA
Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
Posts: 2,645
Not Ranked     
Default

If it started when you first got it, and it does not now, it is something you did to it.

Spark plugs should not be wet. Wet spark plugs will typically not fire. Put the engine back the way it was when it started and try again. Change one item at a time, and you will quickly find the whoops you inflicted upon your engine and yourself.
Davidless likes this.
__________________


Help them do what they would have done if they had known what they could do.

Last edited by eschaider; 02-09-2024 at 09:03 AM.. Reason: Spelling & Grammar
Reply With Quote
  #3 (permalink)  
Old 02-09-2024, 09:28 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,438
Not Ranked     
Default

I always start with the basics: compression, fuel and air in the right mix, and ignition spark at the right time. As you had the heads off, all possible causes are on the table. If it were mine, I'd pull the plugs and do a compression test to confirm the valves are set correctly. Next, I'd confirm the position of the distributor/rotor when the engine is at #1 TDC. Then run the plug wires starting from #1. As the fuel mix is less likely to cause the backfire, I'd button it up and try again. If the problems persisted, I'd look to test, replace or borrow a different distributor to see if that is the problem. Good luck.
Davidless likes this.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #4 (permalink)  
Old 02-09-2024, 09:30 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2022
Cobra Make, Engine:
Posts: 89
Not Ranked     
Default

Quote:
Originally Posted by eschaider View Post
If it started when you first got it, and it does not now, it is something you did to it.

Spark plugs should not be wet. Wet spark plugs will typically not fire. Put the engine back the way it was when it started and try again. Change one item at a time, and you will quickly find the whoops you inflicted upon your engine and yourself.
Thats my problem, the engine is back exactly the way I originally built it.
Reply With Quote
  #5 (permalink)  
Old 02-09-2024, 09:45 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2022
Cobra Make, Engine:
Posts: 89
Not Ranked     
Default

Quote:
Originally Posted by Tommy View Post
I always start with the basics: compression, fuel and air in the right mix, and ignition spark at the right time. As you had the heads off, all possible causes are on the table. If it were mine, I'd pull the plugs and do a compression test to confirm the valves are set correctly. Next, I'd confirm the position of the distributor/rotor when the engine is at #1 TDC. Then run the plug wires starting from #1. As the fuel mix is less likely to cause the backfire, I'd button it up and try again. If the problems persisted, I'd look to test, replace or borrow a different distributor to see if that is the problem. Good luck.
I've done what you mentioned for 3 days, lol. The only thing I didn't do was a formal compression check, but my trusty finger in the spark plug holes while rotating the crank tells me it's about the same as when I first looked for TDC. I definitely feel it's enough for it to start, but I can always get one and check.

Last edited by Davidless; 02-09-2024 at 09:51 AM..
Reply With Quote
  #6 (permalink)  
Old 02-09-2024, 09:50 AM
eschaider's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2006
Location: Gilroy, CA
Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
Posts: 2,645
Not Ranked     
Default

It can not be, or it would start just like it did the first time.

You have either changed something, or something has broken. Your job, "..." as the narrator in the Mission Impossible series says to the fictitious Ethan Hunt, is to ...

Replace the ... with, find what has changed or is broken.
__________________


Help them do what they would have done if they had known what they could do.
Reply With Quote
  #7 (permalink)  
Old 02-09-2024, 11:47 AM
Grubby's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2007
Location: Clayton, IN
Cobra Make, Engine: ERA 838
Posts: 1,066
Not Ranked     
Default

As others mention: check fuel, spark and compression. Take an old spark plug and plug it into one of the ignition wires and ground the body, then crank. There should be spark.

If that doesn’t fix it, I would borrow a compression gage.

John
Reply With Quote
  #8 (permalink)  
Old 02-09-2024, 11:50 AM
Grubby's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2007
Location: Clayton, IN
Cobra Make, Engine: ERA 838
Posts: 1,066
Not Ranked     
Default

One more thing - MSD boxes require 11v. If you are running one, charge your batter.

John
Reply With Quote
  #9 (permalink)  
Old 02-09-2024, 12:08 PM
bobcowan's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Colorado Springs, CO
Cobra Make, Engine: Backdraft, supercharged Coyote
Posts: 2,433
Not Ranked     
Default

If it is backfiring through the intake, then it is firing while the intake valve is open.

Most likely, you need to re-adjust the valve lash.

Before the engine is run, it's really difficult to find zero lash, because the lifters are not really full of oil yet. It's really common to get them too tight at first, which holds them open when it builds oil pressure.

Go around all the valves and loosen them about 1/3 turn. Then see if it starts.

When you get it running, you'll need to go around and do it again, so it's perfect. To find zero lash, tighten the nuts to just finger tight. You'll feel it when you hit zero.
Tommy and eschaider like this.
__________________
.boB "Iron Man"
NASA Rocky Mountain TTU #42
www.RacingtheExocet.com
BDR #1642 - Supercharged Coyote, 6 speed Auto
Reply With Quote
  #10 (permalink)  
Old 02-09-2024, 03:04 PM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,438
Not Ranked     
Default

Bob,
Would turning the engine over (without running) for long enough to hold oil pressure for say ten second be enough to pump up all the lifters? If so it might reveal any lifters that are out of adjustment.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #11 (permalink)  
Old 02-09-2024, 03:12 PM
Grubby's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2007
Location: Clayton, IN
Cobra Make, Engine: ERA 838
Posts: 1,066
Not Ranked     
Default

I would suspect that the cranking to get it running has pumped up the lifters.

John
Reply With Quote
  #12 (permalink)  
Old 02-09-2024, 03:28 PM
bobcowan's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Colorado Springs, CO
Cobra Make, Engine: Backdraft, supercharged Coyote
Posts: 2,433
Not Ranked     
Default

Quote:
Originally Posted by Tommy View Post
Bob,
Would turning the engine over (without running) for long enough to hold oil pressure for say ten second be enough to pump up all the lifters? If so it might reveal any lifters that are out of adjustment.
It should. I usually pre-oil with a drill motor for at least 1 minute before a new start. Probably more than is needed, but it makes me happy.

Quote:
Originally Posted by Grubby View Post
I would suspect that the cranking to get it running has pumped up the lifters.

John
But he's had it apart since then.
__________________
.boB "Iron Man"
NASA Rocky Mountain TTU #42
www.RacingtheExocet.com
BDR #1642 - Supercharged Coyote, 6 speed Auto
Reply With Quote
  #13 (permalink)  
Old 02-12-2024, 03:09 AM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

Quote:
Originally Posted by Davidless View Post
Frustrated
I built a test stand so I could test and run my Ford 427 crate engine before the install in my SF. I recently had to replace both head gaskets because I noticed some oil seepage form the rear of both heads. Then to my dismay my oil was a bright beige in color, WOWE is me. I got the usual from the Ford performance dept… “never seen that problem in 20 years” I at least got a set of gaskets from them because it’s still under warranty.

At first, I thought the engine oil dye I used may have caused the oil color change but after letting some oil test samples set on my counter for a week, I can see some water separation at the top.

After taking my utmost time in changing out the gaskets and adjusting the rocker lash, and re assembling I cannot get this thing to start, it does the typical backfire and flame through the carburetor (timing was not off 180). I quadrupole checked TDC and alignment on #1 cylinder with the rotor cap, plugs are wet, and all valves are opening and closing, plus checked for spark, everything good.

I talked to an engine builder buddy from work and we both are now thinking it might be the Progression electronic distributor/ignition as a possible cause. I talked to them, but they don’t feel its their problem, but I can send it back for them to check.

This just doesn’t make sense. I dressed the engine up from the crate long block and it started right up, and I ran it many times for about 2 months. I was so impressed it would start with 2 pumps within 1 crank, better than fuel injection, so I thought.

Wires were installed as a unit with the cap when assembling so it’s not a wire mix up problem. I’m thinking of sending the ignition/dist. back to see if they can check it, and possibly installing a mechanical type for trouble shooting or eliminating this variable.
Not sure what else to try.

David
This is the first clue. Electronic curves are calculated after a reference angle. Each spark event is a "retard", because of the module calculation, but it appears as an advance curve.
The reference angle is typically 50-70 degrees BTDC.
Are you sure you are following your distributor alignment procedure correctly?
Davidless likes this.
__________________
Gary

Gold Certified Holden Technician

Last edited by Gaz64; 02-12-2024 at 02:33 PM..
Reply With Quote
  #14 (permalink)  
Old 02-12-2024, 07:52 AM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2007
Location: Carlsbad, Ca
Cobra Make, Engine: SPF 2932 with 438 Lykins Motorsports engine. Previous owner of FFR 5452.
Posts: 2,613
Not Ranked     
Default

Itís a timing issue. Youíve got fuel, air and spark. The spark isnít being delivered at the right time.
hauss likes this.
__________________
Jim
Reply With Quote
  #15 (permalink)  
Old 02-12-2024, 08:34 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2022
Cobra Make, Engine:
Posts: 89
Not Ranked     
Default

Quote:
Originally Posted by jhv48 View Post
Itís a timing issue. Youíve got fuel, air and spark. The spark isnít being delivered at the right time.
Yes, I agree because everything checks out. I'm going to try a mechanical dist to rule out my electronic progression dist.
Reply With Quote
  #16 (permalink)  
Old 02-12-2024, 01:28 PM
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2020
Location: New Haven, ct
Cobra Make, Engine: Factory Five
Posts: 14
Not Ranked     
Default firing order

Are you using the 351 or 302 firing order? their different.
most cam manufactures use the 5.0 HO firing order
Reply With Quote
  #17 (permalink)  
Old 02-12-2024, 02:07 PM
twobjshelbys's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2009
Location: Las Vegas, NV
Cobra Make, Engine: Shelby CSX4005LA, Roush 427IR
Posts: 5,456
Not Ranked     
Default

Quote:
Originally Posted by bobcowan View Post
If it is backfiring through the intake, then it is firing while the intake valve is open.
Quote:
Originally Posted by rustyrims View Post
Are you using the 351 or 302 firing order? their different.
most cam manufactures use the 5.0 HO firing order
I wonder if the two are related... Worth checking.
__________________
Cheers,
Tony
CSX4005LA
Reply With Quote
  #18 (permalink)  
Old 02-12-2024, 02:43 PM
fordsrule@msn.com's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2000
Location: Napavine, WA.
Cobra Make, Engine: 427 Classic Roadster-347, AOD
Posts: 52
Not Ranked     
Question crate engine

I know you are talking about a 427 sb , I have a ford racing 347 the firing order is 1-3-7-2-6-5-4-8
__________________
Life is short enjoy it as soon as you can or it may be to late !!!
Reply With Quote
  #19 (permalink)  
Old 02-12-2024, 04:55 PM
hauss's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2018
Location: Lodi, CA
Cobra Make, Engine: 427 manowar forged crank roller rockers . BIG CAM.
Posts: 784
Not Ranked     
Default

something not right with timing .
Reply With Quote
  #20 (permalink)  
Old 02-14-2024, 04:31 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2022
Cobra Make, Engine:
Posts: 89
Not Ranked     
Default

Firing order has not changed, when I removed the electrical to change gaskets I removed the wires, dist as a complete unit so the wires have not be mixed. plus, I triple checked.
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 02:31 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy
Links monetized by VigLink