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Author
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Topic: Engine Problem
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 10-28-2004 12:03 AM
   
I am buliding a 302 for my brothers Fastback and Im having some problems. I put up a post a while back... https://mustangsandmore.com/ubb/Forum1/HTML/013230.html Well I pulled the motor and tore it down. Piston number 5 had heavy scrapes on the skirts and cylinder walls. Also number 4 had started to do the same thing. I took the block back to the machine shop, that had done the machine work on it for me about 40 miles ago. They didnt really know what had caused it and blamed the carb. I had a guy at the local carb shop go through it for me, and he said that I had put it together correctly and didnt see anything wrong with it. The motor did have a miss under a load but idling was fine. The shop bored those 2 cylinders 30 over for me, which they said they didnt like to do (the rest are 20). I put the motor back together, this time with new water pump, pulgs, wires, car, rotor. I checked to make sure the timing mark on my new balancer lined up with TDC and it did. I fired it up and the motor ran good for a few days but had a ticking that worried me. I thought that it was a lifter but it continually got worse. I let the guys at the shop listen to it and they said to pull it out and let them go through it. They went through it and the same two cylinders are screwed up again, 4 and 5. The shop has bored all 8 40 over and I am going to pick the block up on friday. I do not want to have this problem again. What am I missing?? Anybody know?
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fred
Journeyman Posts: 24
From: berea ky
Registered: Oct 2004
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posted 10-28-2004 07:40 AM
Hi,Dumb question, has anyone checked the connecting rods, maybe bent or twisted, there is no other reason for the skirts to score the walls other than dirt or metal in the oil and since the same two cylinders are involved I really dont think thats the problems if nothing else replace the two connecting rods for insurance.
Hope this helps,
Fred
quote:
Originally posted by FSTBK65:
I am buliding a 302 for my brothers Fastback and Im having some problems. I put up a post a while back... https://mustangsandmore.com/ubb/Forum1/HTML/013230.html Well I pulled the motor and tore it down. Piston number 5 had heavy scrapes on the skirts and cylinder walls. Also number 4 had started to do the same thing. I took the block back to the machine shop, that had done the machine work on it for me about 40 miles ago. They didnt really know what had caused it and blamed the carb. I had a guy at the local carb shop go through it for me, and he said that I had put it together correctly and didnt see anything wrong with it. The motor did have a miss under a load but idling was fine. The shop bored those 2 cylinders 30 over for me, which they said they didnt like to do (the rest are 20). I put the motor back together, this time with new water pump, pulgs, wires, car, rotor. I checked to make sure the timing mark on my new balancer lined up with TDC and it did. I fired it up and the motor ran good for a few days but had a ticking that worried me. I thought that it was a lifter but it continually got worse. I let the guys at the shop listen to it and they said to pull it out and let them go through it. They went through it and the same two cylinders are screwed up again, 4 and 5. The shop has bored all 8 40 over and I am going to pick the block up on friday. I do not want to have this problem again. What am I missing?? Anybody know?
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indyphil
Gearhead Posts: 2014
From: Senoia, G.A. USA
Registered: Jul 2002
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posted 10-28-2004 10:00 AM
With all the effort I agree with fred. Something else is wrong. New piston - new bore it cant be much else. Id want new rods and a new crank and make darn sure I didnt go through this again. Someones been getting a lot of work/money out of you, its time to stop the bleeding.------------------
'68 coupe, '66 289 C code
engine, edel 600cfm carb, performer intake, dual exhaust http://www.geocities.com/ottouk_77/68mustang.htm
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 10-28-2004 10:24 AM
Yeah thats one thing I hadnt thought of. But when I tore the motor down the very first time it looked fine. Could the rods have gotten bent somewhere along the line?
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indyphil
Gearhead Posts: 2014
From: Senoia, G.A. USA
Registered: Jul 2002
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posted 10-28-2004 12:23 PM
You cant always see damage. You would need to completley dismantle everything and have EVERYTHING checked. They can sometimes straighten a rod. Often it gets a little bent from a water/oil/fuel leak which makes that cylinder hydraulic lock (rather than lock it might bend the rod and keep running) And like I said you dont always see the damage with your eyes.It might cost more to go over it with gauges than to just go ahead and get some new or rebuilt parts. Stock rods and cranks are very cheap compared to all the labour involved in blueprinting the engine (and eventually replacing the damaged parts) ------------------
'68 coupe, '66 289 C code
engine, edel 600cfm carb, performer intake, dual exhaust http://www.geocities.com/ottouk_77/68mustang.htm
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SteveLaRiviere
Administrator Posts: 40504
From: Saco, Maine
Registered: May 99
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posted 10-28-2004 06:41 PM
Is he using the proper clearances for the pistons being used?------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 10-28-2004 09:43 PM
I talked to the machine shop owner and he assured me that the rods are straight and that the clearances are correct. The machine shop is saying that the carb is leaking gas and washing the oil off of the cylinder walls, which is causing the problem, but why would it just hit number 5 and 4. Could it be a timing issue?? With the firing order 1-5-4-2-6-3-7-8 having 5 and 4 in a row could it be something involving timing? But another thing, the motor did not miss when it ran the second time. What is the best way to test the carb to see if I have a leak? I am going to use a dial indicator to check the lift on the cam and make sure all cylinders are the same. I ran a compression test the first go around and all cylinders were fine. Are there any other tests that you guys can think of? Any other ideas on what I can do...other than junk the motor, which has crossed my mind, and trust me if I didnt have as much money in it I definately would. I have another block crank and rods sitting in the garage, so I believe I will take a couple of those rods and have my pistons pressed on them. Thanks for your help guys.
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fred
Journeyman Posts: 24
From: berea ky
Registered: Oct 2004
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posted 10-29-2004 08:35 AM
Hi,
There is an expression, " mechanics live with thier mistakes, doctors bury thiers".
Do not take a chance with the RODS OR CRANK if you have a known good set use them,I can not see any way that two cylinders at oposite sides of the engine could be damaged by the carb, if it is flodding you would have a start problem , sooty spark plugs and carbon on the valves at those cyl's and even if it was flodding again I do not see any way it could only affect these two particular cyl's, I would ask the machine shop to prove their theory. Let us all know what they say.
bet they can't give you a definete answer and prove it
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 10-29-2004 02:32 PM
Well I'm going to pick it up here in a few minutes so i'll let you guys know what they say. Thanks again.
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SteveLaRiviere
Administrator Posts: 40504
From: Saco, Maine
Registered: May 99
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posted 10-29-2004 08:10 PM
quote:
Originally posted by FSTBK65:
The machine shop is saying that the carb is leaking gas and washing the oil off of the cylinder walls, which is causing the problem, but why would it just hit number 5 and 4.
In 40 miles? No way. I would find out what the skirt clearances should be and measure them yourself or have another machinist measure them yourself. If the carb was washing out the cylinders the rings would show lots of wear also, how do they look? If the rings are ok and just the skirts are wiped, then skirt clearance or rod alignment are the only possible causes as far as I can see. Are the rods in the right positions? If these guys are Chevy guys they sometimes forget that Ford numbers it's cylinders differently than GM. The passenger side on a Ford engine is 1234, while it's 2468 on a GM. ------------------
'70 Mustang Mach 1 351C 4V/FMX/3.25 Open
'70 Mustang Convertible 250 I6/3 speed/2.79 Open
'72 Mustang Sprint Hardtop 351C 4V/FMX/4.30 Trac Loc
'94 F-150 XL 5.8L/E4OD/3.55 Limited Slip
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V8 Thumper
Gearhead Posts: 4346
From: Arizona
Registered: Dec 2001
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posted 10-30-2004 09:40 AM
quote:
Originally posted by SteveLaRiviere:
Are the rods in the right positions? If these guys are Chevy guys they sometimes forget that Ford numbers it's cylinders differently than GM. The passenger side on a Ford engine is 1234, while it's 2468 on a GM.
Exactally. Not only that, but I'd want to verify the seam hole pattern between the heads, gaskets, and block decks. A mismatch will cause a steam pocket to form on the rear of both banks (cylinders 4 and 5) and cause those two cylinders to run very hot.
Excessive expansion/contraction issues could definetely cause piston skirt/bore clearance issues. Early blocks & heads have this steam hole oriented at 12 o'clock direclty over the bore, whereas later motors have them at about 2 o'clock. Very critical that the heads/block/gaskets are all properly matched.
Not to piss gasoline on the fire, but something worth looking into  ------------------
1965 GT coupe, 333ci aluminum headed/solid cammed stroker, four speed, 3.70:1 9" All Blue Oval, no blue bottle
http://mustangsandmore.50megs.com/V8Thumper.html [This message has been edited by V8 Thumper (edited 10-30-2004).]
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 10-31-2004 12:19 AM
Thanks guys. Very good points, and both were things that I hadnt thought of. The block is a 68 model for sure, and I think that the heads are late model. I know that they came off of an 80 model engine, so that definately could be my problem. I am going to do some more checking tomorrow, but I will keep you posted. Thanks
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-03-2004 11:17 PM
Well I checked the head gaskets and water passages on the block and heads. Sure enough they do NOT line up. V8 Thumper you were exactly right. I never would have thought that a head gasket could cause so much trouble. I had the heads rebuilt and they have all new valves in them, so I hate to just set them aside. Can I drill the passages in the heads so that they will line up? I have a drill press and a valve spring compressor, so I could dissassemble the heads if you guys think its necessary. I am planning on assembling the motor on Saturday, and hope to have it running soon. Keep your fingers crossed. Thanks again guys.
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-09-2004 10:22 AM
Well I drilled 1/4 inch holes in the heads using the gasket to mark my holes. I put the motor together and painted it on saturday. Got back out in the garage and lowered her in on sunday. I had it ready to fire up on sunday but I wanted to go over it in my mind and make sure that I hadnt forgoten anything, which meant laying in bed worring myself to death. Last night I fired her up. Motor sounds good. No ticking like before. I let it heat up and got an approximate temp of a couple cylinders, number 5 wasnt twice as hot as the others like before. I AM NOT going to say that its fixed yet! but i'll put some more miles on it and see how she does. Thanks guys!! Without your help i'd still be standing in the garage scratching my head!
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V8 Thumper
Gearhead Posts: 4346
From: Arizona
Registered: Dec 2001
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posted 11-11-2004 07:21 AM
Great news! Glad to hear that it took care of the problem  Next time you run it, leave the radiator cap loose while it warms up (parked, not driving). This helps to evacuate any air that can still pocket up while filling an empty water jacket especially if being run with a thermostat... top-off the radiator once warmed, and enjoy  ------------------
1965 GT coupe, 333ci aluminum headed/solid cammed stroker, four speed, 3.70:1 9" All Blue Oval, no blue bottle
http://mustangsandmore.50megs.com/V8Thumper.html
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-11-2004 09:59 AM
Well I think that fixed it , but its still too early to say it for sure, dont want to jinx it you know. But now im having an alternator problem. I had another alternator sitting on a shelf in the garage and last time i took it to advance it tested out alright, so i swapped them, still isnt charging. Im thinking voltage regulator, Im going to take the alt to advance and test it sometime today. If it isnt one thing its another.
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68mustang351w
Journeyman Posts: 29
From: San Diego
Registered: Sep 2004
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posted 11-11-2004 04:01 PM
if it is the voltage regulator make sure to get a solid state regulator, they are a lot more reliable. David F.
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-11-2004 11:55 PM
Well it looks like the wiring. The alternator is charging, but the current isnt making it to the voltage regulator. Shouldnt be too hard to pinpoint.
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-15-2004 11:45 PM
Well I got the charging system fixed...and I think that I have the motor problem solved. Time to get back at mine. Next project: Power brakes. Thanks for all of your help guys!!!
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Ryan Wilke
Gearhead Posts: 1947
From: Stanton, Michigan 49707
Registered: Oct 2000
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posted 11-16-2004 08:45 AM
quote:
Originally posted by FSTBK65:
Well I got the charging system fixed...
....so was the charging problem just a bad wire, connection, or what?  Ryan
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FSTBK65
Journeyman Posts: 94
From: Salem, Virginia
Registered: May 2004
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posted 11-16-2004 11:16 AM
Well I cleaned and tightened all of the terminals at the voltage regulator and went down to Advance and picked up a voltage regulator for 8 bucks (employee discount wohoo!). I dont know if it was the regulator or the connections or both but its charging now.
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Ryan Wilke
Gearhead Posts: 1947
From: Stanton, Michigan 49707
Registered: Oct 2000
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posted 11-16-2004 12:47 PM
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