Hi all :)
I am not very new in this forum, but I think I was not there for a way too long and my previous account was probably deleted...
Anyway, couple of months ago, I plan to make a complete restauration of SFM 6S779, including bodywork (in order to put the original Ivy green metallic paint back) and the powertrain.
The disassembly of the engine and gearbox attested that they were in a pretty good state actually, but we still need to replace several parts.
I request your knowledge here to help me finding the best parts for this Shelby GT350
Gearbox:
The gearbox is the full aluminum Borg Warner T10M (prod date 1965/07/25). I need to change the different bearing (especially the front ones) + the gaskets.
Which one should I choose?
I have seen the Scott Drake rebuild kit (150$) : https://www.cjponyparts.com/scott-drake-manual-transmission-master-rebuild-kit-4-speed-borg-warner-t-10-289-1965/p/TRK9/
The USA Standard ZMBK166 (55$) : https://www.diffsonly.com/ZMBK166--USA-Standard-Manual-Transmission-T10-Bearing-Kit-1960-1967-4-SPD_p_16939.html
There is other references, like the BK177, what are the differences ?
Engine:
The engine is matching number and has never been opened before (ca. 71K miles). The pistons are still in standard cast.
I need the following parts:
- Complete gaskets kit
- Rod bearing shell (3100 AP Fm inscription)
- Piston rings
- Timing chain
- Alternator belt
- Oil filters
- Core plugs
I think it should be better finding original FoMoCo parts for that? Are they still available and are they robust enough?
Do you have an idea where can I find them? I was used to MustangUnlimited in the past, but their catalog seems to have been on a diet...
Thank you very much for your help
Cheers
Anthony
My recommendation in this new year for your restoration parts AND knowledgeable assistance is Virginia Classic Mustang.
Also, Shelby Parts and Restoration for assistance with your transmission not to mention all the other fine parts and services Jim Cowles offers.
Cheers,
Steve
Anthony,
I would recommend that you change the pistons as well. Some will disagree with me but do it anyway. Think about it, what is the most value part of the engine, THE VIN stamped block and the last thing you want to happen is a piston crack/blow apart and put a hole in the block. Cast pistons do develop micro cracks over time and the pistons are of better material quality now.
Greg
Quote from: kingchief on January 01, 2020, 10:44:41 AM
My recommendation in this new year for your restoration parts AND knowledgeable assistance is Virginia Classic Mustang.
Also, Shelby Parts and Restoration for assistance with your transmission not to mention all the other fine parts and services Jim Cowles offers.
Cheers,
Steve
+1, Brant and his staff are excellent
Quote from: Greg on January 01, 2020, 10:49:24 AM
Anthony,
I would recommend that you change the pistons as well. Some will disagree with me but do it anyway. Think about it, what is the most value part of the engine, THE VIN stamped block and the last thing you want to happen is a piston crack/blow apart and put a hole in the block. Cast pistons do develop micro cracks over time and the pistons are of better material quality now.
Greg
+1 on Greg's suggestions.To add - a custom set of a slightly oversize piston if needed is the better alternative to the standard 30 over sizes . Our resident piston expert gt350hr can be of help if needed. You don't want to bore anymore then you have to. I hope it will stay standard.
Quote from: Bob Gaines on January 01, 2020, 11:40:12 AM
+1 on Greg's suggestions.To add - a custom set of a slightly oversize piston if needed is the better alternative to the standard 30 over sizes . Our resident piston expert gt350hr can be of help if needed. You don't want to bore anymore then you have to. I hope it will stay standard.
+2 :) One of the biggest IMHO mistakes is letting a shop punch a block out to 30 when it doesn't need it. Ford many shops its just automatic using the excuse that its cheaper that way.
Recommendations so far are great. The shops will need to know how you plan to use the car so have a long range goal and plan and they will fill in accordingly - and with recommendations to help out
Good luck
Quote from: J_Speegle on January 01, 2020, 02:29:07 PM
Quote from: Bob Gaines on January 01, 2020, 11:40:12 AM
+1 on Greg's suggestions.To add - a custom set of a slightly oversize piston if needed is the better alternative to the standard 30 over sizes . Our resident piston expert gt350hr can be of help if needed. You don't want to bore anymore then you have to. I hope it will stay standard.
+2 :) One of the biggest IMHO mistakes is letting a shop punch a block out to 30 when it doesn't need it. Ford many shops its just automatic using the excuse that its cheaper that way.
Recommendations so far are great. The shops will need to know how you plan to use the car so have a long range goal and plan and they will fill in accordingly - and with recommendations to help out
Good luck
the reason the shops always did 30 over was that most of the piston companies sold that size cheap . in this day and age you can bore it to virtually any size and get Randy to make pistons that size. you might have to file rings but he can come close
Thank you very much for your help :)
I didn't know that the cast pistons may develop micro cracks over time, so yes it can be more reasonnable to change it (especially since the engine is disassembled)
The cylinders are in a very good shape, oversized pistons are not necessary :).
Which brand / model should I prefer to put in this engine ?
I have checked on Virginia Classic Mustang (+ Shelby Parts and Restoration), but it seems that they do not have the engine parts I need on their catalog.
May they be able to have theses parts upon request ?
Thank you again for your help ;)
Quote from: traxman on January 01, 2020, 04:52:07 PM
Thank you very much for your help :)
I didn't know that the cast pistons may develop micro cracks over time, so yes it can be more reasonnable to change it (especially since the engine is disassembled)
The cylinders are in a very good shape, oversized pistons are not necessary :).
Which brand / model should I prefer to put in this engine ?
I have checked on Virginia Classic Mustang (+ Shelby Parts and Restoration), but it seems that they do not have the engine parts I need on their catalog.
May they be able to have theses parts upon request ?
Thank you again for your help ;)
RaceTec is what I recommend, a great product at a fair price. http://racetecpistons.com
Give Jim a call in the number on the website, very helpful guy :)
"Back in the day" Shelby's 289 Cobra and GT350 race engines used cast pistons and as we all know, they were very reliable under extreme conditions. Replace the originals if their condition is bad or the fit in the bore is unacceptable, but if not, why tamper with the block to refit a forged slug?
Original cast pistons are well known for cracking skirts over time. They start in the radiused area at the bottom of the skirt and migrate upward and inward until a large section breaks off and falls into the pan. As Greg and others mentioned , Racetec Pistons can make forged replacements in "any" size as long as there is a compatible ring available. We do a bore size change for FREE! For "normal" use we use a 4032 alloy high silicon forging for low expansion and quiet running that is FAR more durable than any cast piston. I am not here to "sell" pistons but can help members if they need something.
Randy
Randy, you are spot on. I was putting together an "original to the car", standard bore 427 and took it to the machine shop for a .10 over clean up. I had every intention of reusing the pistons and the machine shop owner, who was well versed in FE's, took one look at the pistons and said did you know they are cracked? I said no because I had looked them over, he proceeded to show me where to look and sure enough 6 of the 8 were cracked or starting to crack to some degree. I was extremely grateful that he saw it.
Use the best that is available for the application you are putting it in.
Anthony, you should contact Randy and let him help you, he is awesome to work with and really cares about the cars and the people that love them.
Thanks for the kind words Greg. There are many here with the same "spirit" . SO many give very helpful information freely to help others and keep this THE best internet source for correct information. I am thankful for the many things I have learned from this group since I have been here. We ARE the best!
Randy
If left unchecked they become very evident, this is from a 100,000+ mile TX 289!
I seem to recall all 8 had some amount of cracks.
I highlighted the cracks with a marker pen.
jim p
Thanks Jim for the pics! That tab ( or tooth as we in the industry call it) it the exact reason the pistons crack! that tooth comes way out of the block a BDC as the piston is "rocking" in the bore from the change in direction. That causes the skirt to flex ( the only way to cause a crack in aluminum) and work harden until it forms a crack. The "angularity" of the cracks indicate that the flex is very low on the piston which it would be at BDC. Removing stress risers from the skirts and keeping the piston in the bore stop the cracking.
Thank you again all of you for your help :)
These microcracks are impressive, I will try to check that in mine next time I have the opportinuty to see my mechanics.
I contacted Randy for the pistons and Jim and Brant for the remaining parts.
Since we need to resurface the cylinder heads + make the appropriate modification for unleaded petrol, we can bring the blocks and the crank shaft to the engine specialist to check the wear and dimension of the shaft and the current bore of the cylinders. As far as we have seen, standard bore will be okay for both crankshaft rod baering shells and pistons
Anthony,
You may not need to modify the exhaust seats for unleaded operation. Usually older heads with "miles" on them do not suffer seat recession like they did in the early 70's Gas formulations have changed a bit to reduce the problem ( in my opinion anyway). Plus the seats have "work hardened" ( read been pounded) for thousands of miles making the OK to use as is.
Randy
So you assume that I can safely use unleaded petrol without any modification of exhaust seat?
I was running this GT350 with unleaded petrol without any leaded additive, and we were wondering if it is safe/reasonnable for the engine over time
I remember a 289 67 Mustang that a friend asked for help with. When I went to remove the pistons, they stated to crumble.
That was the first time that I saw that. I had to take the pistons out in pieces.
As I recall, the car had about 100,000 miles on it and was burning a little oil. ;)
Others may disagree but in my opinion, if you are going to have the heads off why not install hardened valve seats? My original engine was rebuilt in 2011. Machine shop installed new hardened exhaust valve seats after cutting and honing new seats [see picture]. Magnafluxed rods and caps. One piece rear seal and double roller timing chain. Dyno yielded 310 hp in 2011. Still runs super strong with NO leaks anywhere or issues. I would recommend if you can, do everything while the engine is apart. Yee shall be rewarded in the future!!!
Cheers,
Steve
Steve,
The reason not to do it is there is no reason to do it in the first place. IF the heads suffer from seat recession , then by all means have exhaust seats installed. If they do not , you don't have a problem to fix in the first place. Replacement seats have been known to "fall out" if installed with "too little" press fit , and crack the head under the seat if installed with "too much" press fit. Much paranoia was created in '72 when Ford cast a bunch of "junk" 351C 2V heads that had seat recession and horrible guide wear. As I mentioned gas formulations have been improved to reduce seat recession and it rarely happens now days.
Randy
We bring the block to our local shop to check the cynlinders.
Unfortunately, they have taken a conical shape through time... so we have to bore at 0.020"
use a torque plate if available