Website undergoing maintenance, connection may be intermittent
TRExp

TR6 Tech Forum

Dilemma on what course to take on engine rebuild

Moss Motors
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor
AutoShrine Sponsor

Damson1971 Mike L
Orlando, FL, USA   USA
Ok, need some opinions from you all. Not sure what course to take on my 1971 TR6. When I bought the car a number of years ago, it had had the engine replaced with a 1972 engine prior to me purchasing it. Ran well for a number of years, but after about 800 to 1,000 miles the #1 cylinder plug would foul and it would not run right. Had to pull the plug, clean it and then replace it and I was good for another 1,000 miles. Also I developed an oil leak in the pan, and when I pulled it found those dreaded thrust washers in the bottom of the pan. At first I thought it had thrown a ring of some sort but then read up on the problem with the thrust washers wearing and doing just that. Had no idea how long the thrust washers were out. Upon pulling the engine, I found some wear in the crank shaft where the washers were that will require the machine shop to build the crank back up and refinish it if I use the same crank. Haven't really examined the rods or anything else to see if there was any wear from the missing thrust washers. Now i'm faced with the restoration on my 1971, frame off and trying to bring it back to close to 1971 specs. I have found, on the internet a re-conditioned crank from a 1971 and a head unit from a 1971 engine. The seller says it has been pulled from the same engine, a 1971, and reconditioned by their machine shop ready for rebuild. They say they also have the block for the 71 engine that has also been gone through also, so if I wanted I could buy all three units for that engine, the block, head and crank all reconditioned. I guess my question is, should I just go with the rebuild of my current engine, although it will have to be completely cleaned and rebuilt, or attempt to purchase the complete 71 engine parts from the seller. If I purchase them they will be ready for the machine shop to finish and assemble the motor with my other parts, but I do have to consider the cost of shipping added for these heavy parts. What would you do?

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Triumphgt6er Avatar
Triumphgt6er Jim Snell
Cave Creek, AZ, USA   USA
1974 Triumph TR6 "Bubbles"
In reply to # 1505044 by Damson1971 Ok, need some opinions from you all. Not sure what course to take on my 1971 TR6. When I bought the car a number of years ago, it had had the engine replaced with a 1972 engine prior to me purchasing it. Ran well for a number of years, but after about 800 to 1,000 miles the #1 cylinder plug would foul and it would not run right. Had to pull the plug, clean it and then replace it and I was good for another 1,000 miles. Also I developed an oil leak in the pan, and when I pulled it found those dreaded thrust washers in the bottom of the pan. At first I thought it had thrown a ring of some sort but then read up on the problem with the thrust washers wearing and doing just that. Had no idea how long the thrust washers were out. Upon pulling the engine, I found some wear in the crank shaft where the washers were that will require the machine shop to build the crank back up and refinish it if I use the same crank. Haven't really examined the rods or anything else to see if there was any wear from the missing thrust washers. Now i'm faced with the restoration on my 1971, frame off and trying to bring it back to close to 1971 specs. I have found, on the internet a re-conditioned crank from a 1971 and a head unit from a 1971 engine. The seller says it has been pulled from the same engine, a 1971, and reconditioned by their machine shop ready for rebuild. They say they also have the block for the 71 engine that has also been gone through also, so if I wanted I could buy all three units for that engine, the block, head and crank all reconditioned. I guess my question is, should I just go with the rebuild of my current engine, although it will have to be completely cleaned and rebuilt, or attempt to purchase the complete 71 engine parts from the seller. If I purchase them they will be ready for the machine shop to finish and assemble the motor with my other parts, but I do have to consider the cost of shipping added for these heavy parts. What would you do?

Not sure I'd build the crank back up...seems less than optimal to me. I would source one that is in good condition and can be cleaned up and used with standard or over-size bearings (but not so bad as to require building journals back up). If the rest of your engine is good, I'd stick with that and have it rebuilt...you know what you have. I'm sure the seller of the 71 has good intentions but I wouldn't assume anything is really ready to go and assemble unless it's someone you really know/trust. TR6's aren't so rare as to warrant numbers/years matching parts for resale value in my opinion. However, I know how it is when something bothers you about a car...if it bothers you to have a 72 motor in a 71 car and it's worth the additional cost then replace it.

gozto11 Avatar
gozto11 Todd Bermudez
Cincinnati, OH, USA   USA
yeah, unless you have receipts for everything that guy is selling, i don't know that i'd put that much stock in it. i guess the question is HOW MUCH are these parts that you're thinking of buying. there are lots of engines out there on the interwebs where you get the entire thing for not very much. you still don't know what you're getting of course.

i have a '71 long engine and a 75 or 76, but i'm in cincinnati. i pulled the head off the 71 as i'd intended upon sticking it in my triumph 2000 with a different head...long story. before that, i did a compression test. all but one cylinder had really nice compression. don't know why the last cylinder didn't, but the bore isn't scored or anything like that. the 75/76 engine compression was all 50lbs each....i did not pull that one apart.

i'll be in atlanta around 2/10. i could bring one with me, but naturally, you'd need to pay up front smiling smiley

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
Talk to these guys re: the thrust washer problem http://www.customthrustwashers.com

Other than that, if you still feel you need another engine to work with, post a WTB ad in the Buy and Sell section.

rjc157 Avatar
rjc157 ralph c
pearl river, NY, USA   USA
Just fix what you have if you need a new crank you could find one this way you know what was done to the motor a total rebuild is probably going to run you around 25 to 3 grand providing you don't get crazy if your that anal about it try to find a documented 71 motor if you can OMHO

TR3driver Randall Y
Confusion, Los Angeles, USA   USA
I would check the surface in the block, where the crankshaft has been grinding against the missing thrust washer. If it's damaged enough to need repair, a replacement block becomes more attractive. Repairing cast iron is kind of tricky, I've seen several repairs that failed again fairly quickly (even when done by someone that swears it always works for him).

I would also consider having the cap machined to accept another thrust washer half. Twice the thrust area instead of just a harder surface.



Randall
56 TR3 TS13571L daily driver
71 Stag LE1473L awaiting engine rebuild
7? Stag awaiting gearbox rebuild

Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
Pictures would be nice.

As Randall says, I would think the BLOCK would take the brunt of the wear.

I don't think I would spend money building up a damaged crank of block if it cannot be repaired with a custom TW or the addition of a TW pinned to the main bearing cap.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
glcaines Avatar
glcaines Silver Member Gary Caines
Hiawassee, GA, USA   USA
The key is whether you really desire a 1971 vintage engine. If so, seek a good 1971 engine and possibly rebuild it if needed. To be correct, the 71 engine S/N should be lower than the car S/N. I personally would keep the 72 engine, dismantle it, determine damage, and rebuild it if needed. It's possible that there is minimal damage. The 3rd possibility is to obtain a 71 engine, rebuild the 72 engine and sell it. If you do the work yourself, it doesn't cost a significant amount of money. Rebuilding a TR engine isn't difficult and I personally find it enjoyable. A good rebuilt 72 engine will bring you some revenue.



Current: 1973 TR6 W/Overdrive

Previous:
1963 TR3B W/Overdrive
1962 TR3A
1961 TR3A
1960 TR3A
1960 TR3A

barry s Avatar
barry s Silver Member Barry Stoll
Alexandria, VA, USA   USA
1972 MG MGB GT
1974 MG MGB
1976 Triumph TR6
1980 MG MGB
To begin, my TR6 knowledge is limited. I've had my '76 for only a bit over a year. It seems to me that the 'root issue' of this thread is the significance, if any, of having a '72 engine in a '71 TR6.

According to Moss production data, engines from '69 thru '72 were just sequentially numbered engines. At least in this Summary, there are no mention-worthy differences in engines among these years.
while my Heritage certificate lists the engine number, I'm unsure that a differently numbered engine of the same vintage would have any effect on its resale value. To me, appearance and drivability are what make a difference, unless in a "concourse" setting.

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Tonyfixit Avatar
Tonyfixit Tony M
Duncan, BC, Canada   CAN
Yes, (if that is the case) it took me a while to realise it could be a 'matching #'s' issue.

I never understood this, especially with regard British cars that never had 'matching #'s' in the first place.

Some people just seem to make a rod for their own back. C'est la vie

Midgnuts Avatar
Midgnuts Silver Member Dean Webb
Medford,, OR, USA   USA
Having just been thru a major eng. overhaul early in 2017 I would recommend that you take your engine to a reputable eng. shop and let them guide you thru what you need for a reliable engine.
Their reputation relies on their end result.
As far as a 72 eng. in a 71 car - I doubt anyone could look at it in the car and say Oh - that's a 72 eng.
Now I know exactly what I have in my car and feel very comfortable that I have a reliable engine.
Also had the trans rebuilt in the process and installed a Magic clutch kit.

DW


Attachments:
Eng.jpg    44.1 KB
Eng.jpg

getPart.jpg    51.3 KB
Sign In or Register to view this photo
TR 6 oct 17.JPG    80.5 KB
Sign In or Register to view this photo
. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions




Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster