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Severe engine overheat = now overheating oil???

General engine tech -- Drag Racing to Circle Track

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jasonn
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Posts: 56
Joined: Tue Mar 18, 2008 11:28 am
Location: By Rochester MN

Re: Severe engine overheat = now overheating oil???

Post by jasonn » Tue Jun 30, 2020 7:29 am

Dan Timberlake wrote:
Mon Jun 29, 2020 7:04 pm
The couple of engines I've known that had low oil pressure only after warming up each had excessive bearing clearances.
Like, down to the copper.
The rod bearings often suffer first, so the inspection of a few main bearings might have missed that.

I don't understand the cam bearings "squishing", but my bud's dad had a low oil pressure problem when he most uncharacteristically neglected to check the Sunbeam's cam bearings during a freshen up overhaul.
I didn't understand the squishing either but sounded like that babbit material in cam bearings is different than rod and mains?? Idk. So with the excessive heat, that material gets soft it will "squish" out causing the excessive clearance? I have never heard of this either, just what these guys said they have seen. (and like i said coming from a friend who actually talked with them)
1970 mach with mild 351w
11.60's@117
1970 prostreet fastback with pump gas 427
8.81@154

jasonn
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Posts: 56
Joined: Tue Mar 18, 2008 11:28 am
Location: By Rochester MN

Re: Severe engine overheat = now overheating oil???

Post by jasonn » Tue Jun 30, 2020 7:33 am

ProPower engines wrote:
Mon Jun 29, 2020 7:42 pm
Does the cam bearing have a groove on the back side of the bearing??? That and 3 feed holes so they can be clocked correctly??
Been using the Dart supplied bearings lately up here and that is how they are made. Have not tried any others so I am guessing the ford uses the same style as the GM block does.

I would cut the oil filter apart and check for bearing material. If the clearances were correct not any extra then really needed it may well be the mains have been abused enough as well as the rods to open up the clearance to drop the oil pressure.
Or as mentioned the oil pump may have shit the bed and the relief is screwed thus reducing oil pressure.

Time to pull the pan and check the lower end for issues.
Good ? on cam bearings. But I do know that before the overheat, temp was perfect and once it got to normal operating temp, (160-170) , it wouldn not move at all under a short burst of throttle. And oil pressure was perfect also, never going below 40, even hot. So something has definately changed. I think u r correct. Think it will have to come apart one more time for a good inspection. Probably for sure just replace cam bearings and and oil pump just cause these are the last 2 items that have not been replaced after the over heat.
1970 mach with mild 351w
11.60's@117
1970 prostreet fastback with pump gas 427
8.81@154

jasonn
Member
Member
Posts: 56
Joined: Tue Mar 18, 2008 11:28 am
Location: By Rochester MN

Re: Severe engine overheat = now overheating oil???

Post by jasonn » Tue Jun 30, 2020 7:35 am

af2 wrote:
Mon Jun 29, 2020 7:48 pm
Tapping out!! WTH?
Every flippin engine I have ever run will gain temperature. You must have had a special one?
Cam Bearing's? No could be the muffler bearings.
[/quote]

I was asking for some ideas from people who had some kind of intelligence. Go back under your rock and stay out of this thread.
Last edited by jasonn on Tue Jun 30, 2020 7:42 am, edited 2 times in total.
1970 mach with mild 351w
11.60's@117
1970 prostreet fastback with pump gas 427
8.81@154

jasonn
Member
Member
Posts: 56
Joined: Tue Mar 18, 2008 11:28 am
Location: By Rochester MN

Re: Severe engine overheat = now overheating oil???

Post by jasonn » Tue Jun 30, 2020 7:39 am

mt-engines wrote:
Mon Jun 29, 2020 7:51 pm
Same lifters? What's the bore clearance?
Honestly do not know lifter clearance, but yes, the same lifters, so I can rule that out. Almost has to be either the oil pump or a bearing. And since cam bearings have not been checked at all, I think that is where I am at. I will pull the engine out and apart and do a thorough inspection. Replace cam bearings and oil pump. Maybe even rods and mains if there is ANY' sign of wear or damage.

Sure appreciate all the help.
1970 mach with mild 351w
11.60's@117
1970 prostreet fastback with pump gas 427
8.81@154

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