348 Piston valve interference question

Looking at this WSM diagram, I assume if the valves do interfere with the pistons, the interference would be on those areas marked on the piston. Probably a crescent moon from mild to wild depending on the speed on the piston.

Does anyone have a 348 piston that has been interfered with they can post?

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In my mind it seems if I pull plugs, put the car in 6th gear, lift the rear wheels off the ground and spin the wheels in fwd direction the motor should turn. Perhaps only one wheel needs to be up due to the diff. Is that correct?

 

Ha ha, yes I have seen his yes, it's the piston I'm looking for though.

I assume if the piston has light marks but no holes they are still good to go.

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Well I'm joining your exclusive club but with no broken belt.

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I tried it both wheels up no dice no engine turn. I lowered the car, jacked up just one side rear turned one wheel engine turns. Go figure.. I would have thought both wheels too.

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Fantastic, I googled "ferrari 348 piston interference" and found nothing in images. Thanks.

This image looks like Intake interference not exhaust. Its odd how sometimes its just intake that interferes and sometime its all 32 valves like Daniels case. Maybe speed/RPM dependent?

 

I'll start a thread but I pulled plugs and bore scoped it. I took pics of each piston. Basically all of them some very slight. My worst is not as bad as those pics. I was doing 15 mph leaving a light chatting with the wife basically just putting and tragedy struck in between 1st and 2nd shift. I was out of gear actually when it happened. I pulled the belt inspection cap and belt is is still there and has teeth, so belt did not break and it has tension still.

So the cams rolled though and bent them all, lost compression, engine died. eft the light and bang 50 feet later, finished crossing street and rolled into the exon which was rights past the light and called a tow.

I was like, please let it have run out of gas with the swollen rubbers pushing the fuel pump up!
But nope the scope confirmed my horrible sound ears head. Like large ball bearings rolling across diamond plate.

 

Yep I'll start a thread once I get going. I suspect the idler bracket broke and the belt went slack during slow shift allowing slack in the cam gears. I discovered the billet replacement was available from Hill AFTER my major was done. Its been in the back of my mind every time I drive knowing the can break if overtightened. Anyhow we'll see. Will have plenty of question about procedure when I get there, so I'll make a thread.

 

Hi Daniel, I had the fences tacked alright, because you told me about them on the phone when I was ordering.[emoji6]

The timing belt is not broken so the fence did not come loose and shear the belt. Teeth seem to be there too. Picture below. I'm betting on idler bracket. I did not discover that was an issue until after the service. Every time I drive it's in the back of my head. Sigh. But as you say need to get in there. Just did new drilled rotors, and ferodo pads and CV joints and new boots all around, sigh. So horrid OEM pads were.

The belt marks are from the shoes touching the belt, I adjusted them they no longer rub btw. They were not loose so they did their job. Belt went slack is my bet.

Fortunately Olsen machine is near by they do the local Ferrari dealers head work. Problem is, he's retiring so I have some urgency I did not plan budget for.

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10-4 much appreciated! I may take you up on that. especially getting it back in!

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I have a few noticable, few less noticable, and 2 or so that look fine. The camera is rotated in the bore so that last one is the intake side. The camera light highlites them being fresh silver.

Does this mean the intakes hit and exhaust does not? Do folks just replace everything anyhow? Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login

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