Welcome to our resource for MG Car Information.
Triumph TR6 - Enigne rebuild - time and costs
|I am getting myself excited about the prospect of rebuilding an engine - apparently I am easily excited... I suspect that my engine would soldier on for a few years to be fair, especially if I sort out the head. I am thinking of changing to a different cam and increasing compression (might as well, while the head is off, right?), and I suspect that while the bottom end might be okay with the current compression (7.5:1 when new, falling to 1:1 in number 1 cylinder!), the extra stress with higher compression will lead to the early demise of bearings and such. I am still on the fence about doing a full rebuild or just changing the bearings and hoping for the best. I suppose what I am asking is how much time and money do I add to my winter by pulling the engine and doing the job properly? I guess that I add oil seals, a few extra gaskets and piston rings as a minimum. Anything else I will need? Was anyone ever brave enough to keep a record of what a home rebuild cost?|
Thanks in advance for any help or advice.
If the engine is very tired and you plan on keeping the car I think a full rebuild is worth it. If the top half is good but has low oil pressure then do the mains and crank bearings / thrust washers and oil pump while your in there. That will make a noticable difference, it's a job that can be done with the engine in the car though you'll be on your back so have the car as high as you can. I did that to mine 4 years ago and it's still fine, I recall it was all done for around $300-400 in parts and took a few hours.
|Do the full thing Alistair.|
It will add about 10-20 hours of more work to pull and replace the engine as well as strip it down and replace bearings, gaskets and seals. As Charlie says, I think 300-400 is about right for parts. Bearings, rings, seals and gaskets.
You don't say how many miles are on the engine or if it has been done in the past. That may influence your decision as well.
Take a look at the clutch as well. Now's the time to do it if the engine is out.
|I just completed a major overhaul - block magnafluxed and bores checked, crank grind .010, regrind cam by TSI to S2 profile, new pistons, rings, bearings, solid alloy TW, oil pump, timing chain, rebuild head, rebuild rocker arm assy, etc. Also, while the engine and tranny was out we replaced the tranny seals and all the wearing items in the clutch fork assy, and replaced clutch complete. Total with labor probably $4500. Parts and machine shop work about $2700. I used the best trimetal bearings I could find and had the lifters checked for hardness with the new cam - a little more expense. Fortunately, I found a NOS Laycock pressure plate. We could have spent more for line bore block and install cam bearings. Time to complete with machine shop delays was about 3 months.|
We are now 600+ miles into the break-in and she is getting stronger and stronger. No, we did not shave the head. But, you are right in that the increased compression will wreck havok on the old, worn lower end. Do a complete overhaul if you can.
As Charlie B. mentioned, the cost may be truly a function of what you want to spend and how long you plan to keep the car. Out 73 TR6 - "Magymae" has been in our family for 30 years and is not going anywhere else.
From my experience, I would only attempt a home complete overhaul if I had specific TR6 engine rebuild experience. Otherwise, I would find a reliable LBC speciality shop who will guarantee his work for at least 12,000 miles, and pay for that skill and peace of mind. I only wanted to do this one time.
|Alister, I did my head 2 years ago, bumped compression, etc. After that my engine wouldn't run for more than about 20 miles without fouling plugs, even though I had compression numbers in the 130 to 140 range I was still getting massive blow by past the rings. Ended up doing a total rebuild. I would say do it all, especially if you are going to up your compression.|
|Thanks for the fedback guys. I am still not sure which way I will go - part of me says to keep the compression stock and forget the cam change, after all I don't find the car all that sluggish firing on only 5 (sometimes 4, I think) cylinders. On the other hand I had the pleasure of driving a TR6 PI in England a few years ago and I would like to get a bit closer to that performance. |
I really don't want to pay someone to do anything I can realistically do myself - long suffering members of this board will know that I took a welding class last winter to allow me to do the diff mount reinforcement myself. I have feeler gauges and a torque wrench and I can follow directions (or ask here how to follow directions!), so unless I get hopelessly lost, all but machine shop work will be done in my garage. I suspect that I will regret all of this confidence at some stage, but there it is for now!
My current thinking is to take the head off as soon as the weather turns cold, and have a look at the cylinder bores. If they look okay (anyone like to define okay?) then I will leave well enough alone and do the bearings from underneath. I guess that while doing the bearings it would not be too much extra work to replace the rings? If the bores look scored or anything else looks dodgy I suppose the block comes out to go to the machine shop. Other than installing cam bearings, what other reason is there to take the engine out? Aside from the fact that changing the bearings doesn't mean lying on my back for a few hours while oil drips in my eyes, of course...
Thanks again. I am off to England for a few days now - anyone need anything from Rimmer Bros!?
|Nothing like skill and confidence to get the job done.|
Obviously, the engine comes out if there is any damage to the crank journals. Have a great trip to UK.
Keep the head stock and add a supercharger. You'll get all the horsepower of the PI motor without all the head mods.
Can't afford Rimmer Bros, but I could sure a couple of bottles of Moss Towie (that's a single malt scotch out of production since 1983) if you happen to run across any:-)
This thread was discussed between 31/08/2007 and 02/09/2007
Triumph TR6 index