59 L 276 Stroker Problem during start up

[Flathead Ron]

Hi Guys,

I need to pick someones brain. Im looking for some thoughts and input if you agree or might it be something else ???????? So here is the story.

i Had a problem during start up a couple days ago. I was trying to start up and after canking and a few pumps of the throttle I realized the coil wire on the distributor was off. I connected it and tried to start it (most likely flooded). My finger slipped off the key and I grabbed it again and hit the starter. In the brief moment my engine stopped cranking it popped in reverse rotation while iI was engaging the starter again. It sounded bad but I ran it over again and it sounded ok so I started it. I'm so lucky I had mufflers on it or i would not have heard the rattle. The reason I had mufflers on it is I changed the valve timing10 deg advanced which is where it was when I initally disassembled I always make sure I have mufflers on after any major changes in case something happens. Not even loud as a tappet, but i heard it. Dropped the pan pulled the rod caps and #4 had just started to delaminate because of being partially crushed. I cchecked the others and they all had a strange wear pattern on the outside edges but no detectable difference more then 0.0005 except #4 and a chipped starter gear with a bent shaft

So, Im figuring this is what the tap tap was but the wear on the outer edges was this something coming on.

Additional Info

I did have a throttle spring break sending my flattie in to RPM overload for a split second. This is when the oil pump failed. I didnt see the zero on the oil pressure until I restarted it and it was idiling for a minute getting ready to leave. Shut it down. Only had about 1K miles on the clock. Have a Frantz Oil Cleaner and I tear it apart every time I change the oil and I run Zinc.

Thanks For Reading


If You have any Ideas on what would wear just the outer edge of the bearing. Is it possible the revs north of 5K with almost no oil started the outer edge wear. Nothing detectable ever in the oil.

I've been driving two years and about 600 miles since the over rev and pump failure.

Ron...

[Bored&Stroked]

You need to tell us what year engine, what crankshaft, what rods and what bearings in order for any opinion to be rendered.

The typical reason for wear on the sides of rod bearings is that they are rubbing on the crankshaft fillets (though only on the outsides) - usually on full-race crankshafts where a big fillet is used and the bearings have not been correctly clearanced to stay clear of the fillets. I've not seen this issue on a flathead before. Another issue could be if you have aftermarket rods (like H-beams) and do not have the outside clearance bevels against the crankshaft fillets (have them in backwards). This is easy to do and can cause issues as well.

Also, I wonder whether or not you advanced the initial timing too much and that is what caused the engine to go into reverse rotation? I've started plenty of angry flatheads in my time, and I've never had one go into reverse rotation - not ever. This includes race flatheads where we have "locked down" timing at 26 degrees BTDC.

If you had no or little oil and the over-rev situation, then this could have caused the issue at the start. Without a pressurized oil film, the bearings can have metal-to-metal contact and this can damage a bearing in a very short while. Do you happen to know what your original bearing clearances were on the rods?

You might want to post some pictures of the bearings you mentioned . . .

[Ggmac]

I agree with Bored & Stroked , ive only seen it on sbc when using either the wrong bearing for the crank or the crank not ground correctly.
Ive had a similar runaway on a build early in my career .. I have since used dual throttle return springs on everything. One one the top side going foward , one on the bottom shaft going to the rear . I do it this way to equalize the wear on the shaft with dual springs . If they were both on the same side of the shaft the wear is increased in one spot .

[Flathead Ron]

I was trying to reply to your post but I hit the button to post my reply and it booted me out I had to login all over again and then my message was gone it took me 20 minutes to write that darn thing. I’ve updated my personal information and you can send me an email if you’d like. I’ll try to post a response but I can’t guarantee it. I’m so computer illiterate.

[Flathead Ron]

I like your post. You’re exactly right. I tried replying to the other gentleman and I guess I took too long writing my reply in a boot in the out but I’m with you guys I have a YouTube channel called flat it runs garage and I’m on Instagram and there are pictures on there and on my YouTube channel I show you the bearings. When I figure out how to navigate through the site a little faster and I could do things without getting booted out I’ll post a picture. Have a wonderful day, Ron.

[Mart]

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Gents of the barn: Can you please have a look at Ron's video. I looked at it and you can see my response. I suggested he ask for opinions on here.
Here's the link to Ron's video.

https://youtu.be/KFVb5s4wlR0

Please have a look and chip in if you have any idea what could have caused the unusual wear problem.

Thanks very much.

Mart.

[Mart]

Ron, if you advanced the cam 10 degrees, did you also advance the cam by 20 crank degrees in doing so? Or did you "retard" the distributor to keep it in time with the crank? I don't tend to mess with cam timing, what would be the reasoning behind advancing the cam by 10 degrees?
The cam gear has 44 teeth, so one tooth "out" would move the cam timing by 8.2 degrees, or 16.4 crank degrees. Was that what you did? 1 tooth?
Hopefully some of the experienced builders will be able to shed some light on your bearing issue. Personally I think the startup overrev and oil pump failure will have caused the damage and the mis start was the straw that broke the camels back and caused enough extra stress to cause the noise.
Is it still a case of new shells and button it back up or are you going to tear it down further?
Mart.

[Bored&Stroked]

As Mart noted, did you advance the cam (which my guess is that you didn't), or just change the ignition timing? To me, the rod bearings look like they either didn't have enough oil or the clearances are too tight - or the crank was not ground correctly.

What rod journal clearance do you have? Also, now this is going to sound like a dumb question, but how many oil holes are in the rod journals - 1 or 2? I can't tell which crank is in the engine and I've seen situations where folks put 49-53 rods on a 39-48 crankshaft - starving the rod bearings of oil.

I seriously doubt that the pop-back against the starter was the issue - as all it did was kick-back . . . and I've done that before and bent a starter shaft as a result. If you kept that starter in the car afterwards, then you may just have a bent starter shaft and it was dragging on the flywheel ring gear.

I'd replace the rod bearings, but not before I did some real accurate measurements of the crankshaft rod journals and used a precision bearing mic or dial-bore caliper to determine the rod bearing clearance. There has to be a reason why the bearings are polished like that - and my guess is that it is a clearance issue from the get-go.

[Flathead Ron]

Hi Mart,

This is the configuration the motor was in when I purchased it, the valve timing was 5° advanced at the crank marked on the gear and the advanced hole on the timing gear. I believe that’s a total of 10°. Also I think I had the distributor timing too far advanced. This motor used to be a blown motor. Maybe this has something to do with it. I wanted to put it back in the configuration just to see what difference it would make I’ve never had a flat head motor with the valve timing advanced 10°. Guess I shouldn’t have messed with that huh. Anyway the Motor is out, the heads are off and I’m going to sit down and put together another video tonight and publish it.

[Bored&Stroked]

Hey Ron: You have it backwards . . . if the valve timing is 5 degrees advanced at the crank, then it is 2.5 degrees on the cam (cam turns 1/2 the speed). There are plenty of folks that install camshafts advanced - especially on more modern OHV engines (where it is easy to do). As a matter of fact, many cam grinders started deliberately advancing their cams (as they were ground) for many of the street grinds they were cranking out.

One needs to know the cam timing details to know where it should be, where the intake centerline is, etc.. With a degree wheel and a lot of cam timing knowledge, one can figure it out - but most folks don't have the tools or knowledge . . . so the cam grinders just stuffed in the advance into their grinds from the get go.

BUT - we really know nothing about your situation - in that without having specific cam timing information (from the CAM manufacturer and your specific engine), we don't really know where the cam is . . . and how it was installed and for what purpose.

What do you know about your cam?

[Mart]

Ron's having computer problems but has posted a video showing some of the details of the rest of the motor. Check it out..

https://youtu.be/QdeZPHLlgNs

Mart.

[Flathead Ron]

I’d like to thank everyone for taking the time on my problem. Motor is out and I’m disassembling. I’ll try to remember to keep you posted. Still nothing shiny in the oil.

You guys are great. Thanks. I’ll figure this computer stuff out.

Ron

[Ross F-1]

This shows what my first thoughts were, that the rod journals aren't correctly ground. From a Mahle brochure

[Flathead Ron]

I’ll try and find some information the cam. It’s a Harmon & Collins 3/4 grind. Thanks again for your time.

[Flathead Ron]

Well once it’s a part I’ll find out. I’ve got all the tools I need to measure everything in there. If it needs a crank what would you go with one of the Scat, Eagle, or ? crank. Big difference in price.

[Fordestes]

Unless your crank is beyond servicing , I would find a Ford crank and proceed before going to an offshore crank, also make sure the rods are within spec. have the rods checked , if the crank is distorted the rods no doubt will be , you said it was a blown engine prior to you owning it , there could be a lot of distortion ,not knowing how it may have been abused .