1968 GT500 428 PI overheating / burning oil

[Hoffi]

Hi,
my name is Michael and I just got a 1968 GT500 428 PI. The previous owner sold me the car with a ,,just rebuilt engine". From what I can see from the outside all gaskets and stuff is really new but the car burns oil (I can smell it and from time to time theres a blue cloud passing by when I stop at a red light. The valve stem seals just have been redone, no change.
Also the car does overheat, I changed thermostat, put an Edelbrock HiPo water pump, put a new 3 row radiator, a new fan clutch - still the car does overheat.
Maybe anyone of you has an idea? I really love the Shelby but since I got it it drives me crazy insted of bringing me joy and fun...

Thanks
Michael

[Bob Gaines]

Hi,
my name is Michael and I just got a 1968 GT500 428 PI. The previous owner sold me the car with a ,,just rebuilt engine". From what I can see from the outside all gaskets and stuff is really new but the car burns oil (I can smell it and from time to time theres a blue cloud passing by when I stop at a red light. The valve stem seals just have been redone, no change.
Also the car does overheat, I changed thermostat, put an Edelbrock HiPo water pump, put a new 3 row radiator, a new fan clutch - still the car does overheat.
Maybe anyone of you has an idea? I really love the Shelby but since I got it it drives me crazy insted of bringing me joy and fun...

Thanks
Michael

Michael ,wow the possibilities are many. They could be related or independent of each other.  The oil blow is a very bad sign. It could mean the rings didn't seat, were installed wrong etc. it could also mean the intake was installed wrong and oil seeping by intake gaskets(given the new valve stem seals).  The over heating could be radiator or because the new rebuild engine was built too tight of clearances . The other typical overheating culprit can be because the engine was bored too much at rebuild. Unfortunately given the symptoms and the tried fix's leads me to lean towards a poorly done rebuild. Others may suggest a few things to try be fore pulling the engine and doing a inspection.  A inspection by a knowledgeable engine builder and re do is most likely the ultimate answer. Don't shoot the messenger . Just giving my opinion. I hope that I am wrong. 

[shelbydoug]

The oil issue could very simply be a problem with the pcv valve. Either the valve itself or the installation.

You need to define what you mean by overheating. What is the engine temperature it is operating at or overheating to?

[Greg]

Michael,

First, take a deep breath and relax.  It is frustrating and that frustration will only get worse if you start throwing money and time at it without a methodical plan.  As Bob indicated, the possibilities are vast but I would do the following to narrow it down.

1) Pull the plugs and look at them, if some are oily that will localize the area to look at.
2) Do a compression check on all cylinders and compare the results, this will also localize the issue.
3) Pull the valve covers to see how much oil is getter to the valve train as it may be too much.  Everyone wants to use a HV oil pump regardless whether its a street car or race car and frankly, that causes more issues in a normal street car engine that isn't turning 7-9K RPM (Ford knew what they were doing :-) ) .  I have see the valve train flooded with oil and it will cause an engine to smoke like a cigarette.
4) You didn't mention the engine running rough so I don't expect you have a vacuum leak.
5) You say it over heats but what is the temperature?  Don't make the mistake of putting a 160 deg thermostat in it thinking that will make it run cooler, it won't.  A 180 deg is better because it allows the radiator to do its job by keeping the coolant in the tanks longer so the air and fan can cool it through the fins.  Running 200 to 210 is not uncommon for a BB FE engine and make sure the radiator isn't filled to the top as it needs some expansion room.

This is a good start, let us know what you find....  Remember take it slow and do it one step at a time.

BTW...Congratulations on your new Shelby, it will work out and you will be happy.

[Bill]

Something not mentioned, and an issue when I had my motor rebuilt, was timing, and the vacuum advance and vacuum source. Fixed those minor items (recurved the distributor too boot), and the car runs at 180-195 degrees all hot, humid summer long in stop and go traffic.


Bill

PS: Besides radiator, look at your lower radiator hose and make sure there is a spring installed to prevent the hose from collapsing under suction pressure from the water pump. Also look at your fan, or if equipped, your fan clutch assembly.

[The Troll Free Zone]

Something not mentioned, and an issue when I had my motor rebuilt, was timing, and the vacuum advance and vacuum source. Fixed those minor items (recurved the distributor too boot), and the car runs at 180-195 degrees all hot, humid summer long in stop and go traffic.


Bill

PS: Besides radiator, look at your lower radiator hose and make sure there is a spring installed to prevent the hose from collapsing under suction pressure from the water pump. Also look at your fan, or if equipped, your fan clutch assembly.

Come on. Lets not tug on that thread again. Pumps pump, they don't suck or they would be called sucks!

If you lower rad hose collapses you have a restriction in your radiator. Since the OP installed a new three row rad I doubt his lower hose is collapsing. Enough with the urban legends.

JMHO(if I type those 4 letters I cam say anything) 

Chris

[1968shelbygt350h]

first thing is to try to get in touch with the seller and let him give you the rebuilders information and try to find out how qualified the shop is in rebuiding engines or maybe the person who sold you the car attempted it ,by seeing what poor engine shops have done this is the first thing to find out also you need engine specs to know whats in the engine bore ,valves ,cam if water jackets are clean rings incorrectly installed if not best thing is to do a tear down 

[6s1802]

Find a G.T.350 save yourself the headaches

[1967 eight barrel]

Well, being you mentioned the rebuild was "new"  How many miles have been put on post rebuild?. Some rings may take several hundred miles to seat.  I had a similar issue piston to cylinder wall clearance issues. Cast and Forged pistons require different clearances, so if the builder didn't allow for material expansion you may have an issue.  Does the engine seem to struggle a bit to start/turn over after it comes up to operating temperature?  If so, it's likely piston clearance issues.
I used oil restrictors in the heads to reduce over-oiling for the rocker shafts. Because the drain back can be sluggish, often the excessive oil can leave up to a quart in each head, which also causes oil starvation for the rest of the engine.
I had my block sonic tested and it turned out to be quite thick. I was fortunate. Many are scalely which also causes heating issues.  My fan clutch was worn, so I sent the original out and had it rebuilt ( 10 months) and in the interim replaced it with an over the counter thermostatic unit. The other possibilities are the radiator, thermostat.  You have plenty of possibilities.  If you have a .060 over 428, you're likely in trouble.  The issue mentioned with the lower radiator collapsing is a simple fix. It's caused by the absence of the hose support spring. It's a whole six dollars from NPD. The lower hoses used to be supplied with them. However, even the Kevin Marty hoses are no longer supplied with them.
Anyway, we can hope it's something simple like timing and mixture.
Let us know what you find.
                                                                                                  -Keith

[1967 eight barrel]

Find a G.T.350 save yourself the headaches

If I wanted a small block I would have bought a falcon...  Besides, I love smoking the punks. 
                                                                                                  -Keith

[shelbydoug]

Well, being you mentioned the rebuild was "new"  How many miles have been put on post rebuild?. Some rings may take several hundred miles to seat.  I had a similar issue piston to cylinder wall clearance issues. Cast and Forged pistons require different clearances, so if the builder didn't allow for material expansion you may have an issue.  Does the engine seem to struggle a bit to start/turn over after it comes up to operating temperature?  If so, it's likely piston clearance issues.
I used oil restrictors in the heads to reduce over-oiling for the rocker shafts. Because the drain back can be sluggish, often the excessive oil can leave up to a quart in each head, which also causes oil starvation for the rest of the engine.
I had my block sonic tested and it turned out to be quite thick. I was fortunate. Many are scalely which also causes heating issues.  My fan clutch was worn, so I sent the original out and had it rebuilt ( 10 months) and in the interim replaced it with an over the counter thermostatic unit. The other possibilities are the radiator, thermostat.  You have plenty of possibilities.  If you have a .060 over 428, you're likely in trouble.  The issue mentioned with the lower radiator collapsing is a simple fix. It's caused by the absence of the hose support spring. It's a whole six dollars from NPD. The lower hoses used to be supplied with them. However, even the Kevin Marty hoses are no longer supplied with them.
Anyway, we can hope it's something simple like timing and mixture.
Let us know what you find.
                                                                                                  -Keith

Absolutely. The reaction of an FE block to over boring it is documented. Even just going .030 over allows some really nasty changes to the operating characteristics of an FE.

Current thinking is IF POSSIBLE, just hone out the bores trying to keep it to just a few thousands over stock.

All said though, 210 to 220 F is not overheating. These things just run hot and did when they were new also.

You are running on a pressurized system similar to current emissions engines that go as high as the 240's.

A 428 in a "Mustang" chassis is not for a novice. They are strange ducks and require more patience that many people will ever have. Are they worth the trouble? Kind of like being married to "the Playmate of the year". It has it's advantages and it's pitfalls?

Fortunately there are no lawyers involved. 

[67gt500]

I just finished my 428 and we started with a standard bore block that had just under 15 thou wear. We got some 15 thou custom CP pistons from Blair Patrick and Honed the bores.. It cost more to do it this way, but the results are better. Also spend time on getting the intake manifold Square. Again takes time and depending on what has been milled off the block or heads, will require it to be sent to the machine shop to have it milled.. But it is worth the $$.. no sucking oil from a poor fitting intake manifold.

[KR Convertible]

I had trouble with running hot too.  I added a mechanical temperature gauge, that I tested in boiling water.  It is a Bosch 2" gauge that I keep in the glove box.  I installed the probe in the thermostat housing where the vacuum switch goes.  Now I know the actual running temperature.

I had my radiator tested and found out it was only flowing about half of what it should.  Ended up having it recored.

Installed a Mr Gasket high flow 160 degree thermostat.

I also replaced my fan clutch with a $50 piece from the parts store.  It actually made my car run a little hotter.  If you are not concerned with originality, you might want to try a direct driven fan. If originality is a concern, spend the $400 and get one of Chris Brown's repros.  The clutch fan was my biggest problem.

[Hoffi]

Hi, first thank you all for helping!
The engine supposenly just has been driven for about 200 miles after the rebuild, maybe even less. I recently put new sparks the old one still looked good none of them was greasy. I put a new Hayden thermatic fan clutch. Also the radiator is a brand new 3 row, the thermostat is a new 180 degrees like the assic Ford parts list told me. I ordered the lower radiator hose spring, cant hurt to put it there. The temperature gauge was defect, I got a Scott Drake replacement part that I dont really trust... It goes up to like 4/5 of the gauge, its at 1/2 of the gauge after like 2 miles. Now I got a rebuild original Ford one that I will install this weekend... Last time I used the temp laser gun after I replaced the fan clutch (got a little better), heads (front part towards me standing in front of the car) and intake (where the temp sensor (also new) sits) had 220 in idling condition and went up to like 230 after shut off. I took out the PCV valve today, the grommet is kind of dry (original one) is goes easyly in and out, but the valve itself clicks every time I shake it, anyways got a new valve and grommet that I am also going to install. One thing I didnt check yet since I got the Shelby was the timing, maybe Ill habe to check on that too.

thanks
Michael

Thanks
Michael

[shelbydoug]

You need a gauge that will give you numbers, not just high or low.