Sometimes, things have a way of getting "bumped" when they are being moved around....accidents happen...
Well here are some pix of the damage..........Valve pix are not the best, but you can see that the valves just don't seat all that well after making contact with the pistons!! Also some pix here of the "dings" in the pistons.......other than that, the only other damage I can see is to my........................wallet!!! Bent, dinged & penniless ME Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Kerry, I have been following this thread since the beginning and I am sorry this happened in the first place. I hope you the best on the repairs! Trying to always learn more about these cars, I was wandering if you could, or someone else, entertain some questions about what I see in these pictures. My questions: if you just repair the valve related damage and leave the pistons alone, what would be the estimated longevity of the pistons, in the general sense, with the damage sustained?, and how would the car behave with this unfixed? I see some pistons that look really dirty (black deposits. oil residue perhaps?), while at least one showing really clean. Is this a consequence of the damage? or was something else taking place that may be considered normal (perhaps the right words would be "not serious")? Obviously you don't have to answer these questions, but if you or some else does, I'll appreciate the teaching very much, thanks!
Kerry, How do the camshafts look like? Do they show sign of abrasion, like if one of them seized for a moment? I ask because that's what happened to me last fall. 4 valves needed to be changed, camshaft and both heads tooled. Pistons marked but nothing to do on that side. Everything doable. But what a hole in my wallet. Anyway all this sounds and looks familiar to me. Courage, money and beer will do it.
Bottom two pics are the same...he just wiped the piston clean to inspect for obvious cracks....compare the gasket markings and you will notice they are the same.....
So Kerry.....are you looking at only two valves that are bend or did your inspection revealed more? If just two then taking the totality of the BANG, it would be a little easier on the bank, huh?
I believe I counted all six pistons on the one side been scored. wouldn't all 24 valves need to be replaced?
You are right! I missed your post before I posted my previous with the 24 valve count. Hopefully for Kerry, it is less than that number.
Ah, Cracks, I had not consider that! Now it makes sense to inspect/replace the pistons as well. Perhaps there are other factors why to do it that I will become aware as Kerry progresses with this job.
I gotta tell you...to my totally untrained eye that doesn't look too bad... What do you figure it will be in materials cost? 12 valves or so... Gaskets... Belts... Bearings... Valve guides? Do you have to have the head/valve seats machined? Or is it reasonable to just replace the valves, and lap them? Its a slippery slope... Do you just do the one bank if you are doing machine work and valves? Both? Remove the psitons? etc... Would it be lunacy and complete mechanical disregard to just do a "limited scope repair?"
I have seen lots of TR motors with belt failures. This one looks just like all the rest. Too bad the cams turned long enough to ding all the valves. Many shops take the opportunity to sell the moon but no need and no benefit to the owner. Pistons are fine. He could replace the 24 valves and lap them, put it back together and the motor will be every bit as good as it was before the belt failure. Any more work than that is otional. TR valve guides have never been problematic. I am sure if they were measured someone could make a case for replacement. It will not make the car run any better and the ones in the motor now will last well into six figure mileage.
I'm sure Kerry will be relieved by your assessment, Brian --- sounds not so bad. Any advantage to smoothing out the gouges in the pistons, or just let them go as they are?
Brian, whats a ballpark $$$ figure to do that? If you assume a major is $6000 or so (ballpark, I know), how much additional is it to fix the valves on one head? $2000? $4000? More? I was really expecting the cylinder dome and pistons to be more thrashed. Oh, and as an aside, kudos to folks who have taken out their own motors. I just finished doing this on my 930, and its a huge PIA. A 3 week project quickly morphs into 6 months. Typically this involves lots of free "buddy" labor too... After about 2 months of looking at the car in pieces in my garage...what proffesional mechanics like Brian charge for ferraris seems really resonable...
I hope that your assessment is correct as well for Kerry's sake. And thanks for your comments, your assessment largely answers my questions above as well. I was also wandering about valve guides and any stress they might had suffered as a consequence of the valve deformation. I hope that you assessment in this is right on as well.
Judging by the 4 crescent impressions on each piston it would appear that both the intake AND exhaust valves hit. Two at the beginning of the cycle and the other two at the end of the cycle. (Being a 4-cycle engine)
No. The same belt drives both the exhaust and the intake camshafts on each bank. One belt per bank of cylinders --- not one belt per intakes / exhausts.
Ya, I'm somehow thinking wrong. I'm thinking if the belt skips the piston comes up early and hits the exhaust before they close....but then it should be long past TDC on the way down before the intakes start to open. I'll have to re-think it. I had an exhaust cam chain break on Jag V8, but it only affected one hole. I was thinking (without thinking too hard) that a Ferrari might get away similarly. But of course the engines are very different.
Been watching this thread for the good stuff that I can now ask questions about: 1) Is it worthwhile to polish or machine out the dings in the Pistons? 2) Is there a good way to check the valve guides in this case (other than visually), because if even one is bad, couldn't that be catastrophic? Brain, Thanks for all the info and answers! Kerry, Didn't wanna log on just to say how bummed I am to hear about the trouble, but now that I am, I am very sorry to hear about the engine trouble, and I am a little envious that you are brave enough to take on the task of fixing it yourself! Go Kerry!
1) Apparently most feel that removing the gouges is not necessary. But, if it were my engine, I would at least make sure there are no burrs or pieces that could shed off later. 2) Using a dial gauge, lateral play of the valve stems can be measured (springs must be removed). This is a good indicator of valve guide wear / damage. But, since the valves are going to be replaced anyway --- best method is to measure the guide ID with a bore gauge.
I just use a bearing scraper and take off the sharp high spots. Any more than that isn't really needed. Valve gides would naturally get some scruitiny when the valves are removed but unless I found something pretty bad it would take some convincing to get me to start replacing them in a motor that ran well and didn't smoke or use oil.
1) Standard procedure in the aircraft world is to remove all sharp features from the damage, blend the bottom of the gouge so it is smooth and tapers gradually back up to the original surface, usually a 20 to 1 ratio. The reason for this is to try to eliminate the possibilities of stress risers that could later form into cracks. Ideally, after the blend and polish is done, an eddy current inspection is done on each damage area to check for unseen cracks. Ultrasonic inspection can also be used. Depending on the depth of the damage this might be overkill. Just sayin' After this process was complete I would feel pretty good about the pistons.
Update...............36 valves and all 48 guides will be replaced............no reason to give the other head a blind eye as long as I am this far! By the way anyone know of best pricing for a complete gasket and seal set for an '87 TR? I think I may sell the 24 bent valves & 12 straight valves off as "unsuitable" paper weights to help offset the cost of this "rebuild'...If interested..............$12 shipped within the US of A. Supply is limited to just 36...so don't wait too long to order your F car momento today! I'm serious, really I am. Entrepreneur Me