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1500 engine rebuild, suggestions for improvements?

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recordsj

Jedi Warrior
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I have a 1500 engine that I am considering rebuilding because of issues with the piston and/or cylinder in the engine that doesn't hold pressure.

If I do the rebuild, any suggestions?
Suggestions to on improvements of the engine and etc (without adding $100 of extra cost?)?
For improvements I cam not looking to add HP or performance, I am more looking to add durability and strength to the engine.
 
The folks in the Triumph part of the board will certainly have some suggestions for you.

For reliability, pin the thrust washers. There are also some oil galleys that can be drilled out to improve oil flow to the main bearings. When putting the engine back together, use a new oil pump. Before installing it, lap the end of the body down so there is less than 0.004" clearance between the gear/rotor and pump end plate. Also fit a new oil pressure relief spring as they can relax a bit over time. In the end you should have higher oil pressure all around with more flow to the bearings. The folks on the Triumph section should be able to talk a bit about drilling out the galleys.

If you don't get the information on this board, Google for "Deborah Evans, Priestess Race Engines". She is an engine builder in the U.K. who has extended her A-series work to the 1500. One of her articles on the 1500 can be read in the link below:
https://www.visn2.com/Flash%20Website/1500_Replacing_Main_and_Rod_Bearings.html
 
I already have a weber dgv carb on it and don't want to have the added cost since I am content with the weber.

I am more looking to see what can be done to add life/durability to the engine since I will be doing a rebuild, not necessarily looking to add hoursepower or performance out of it. Don't want to add $100's of extra cost to the rebuild since I just use the car as a fun car to drive.
 
what kind of cost would you thing that would be to blance the crankshaft? Do you have real experience in what the cost would be?

What improvement would I be getting to have the crankshaft balanced?
 
Don't stop at the crankshaft. Balance all the parts that move with the crank... pistons/rods, flywheel with clutch, and pulleys. The price varies from shop to shop but when I last had this done it cost about your limit of $100

The crank and bottom end of the 1500 are its weak spot. Please do read the article(s) at the link I posted above.
 
One thing I always do on my 1500 builds is when I replace the camshaft, I use a 1300 camshaft and that allows me to to use the 1300 cam bearings as well. What the factory did with 1500 to save money was increase the camshaft journal size to be run in the block without cam bearing, the only difference between the 1500 and 1300 camshaft is the 1300 camshaft is a smaller diameter journals and the 1300 block use cam bearings, the cam journal bores in the 1500 is the same as the 1300, and the 1300 cam bearing fit right into the 1500 block.

I'm not a fon of screwing or pinnng the thrust bearings, it's a bandaid fix, here's the deal, there's not alot of room to work with and and as the thrust bearing wears on the screwed or pinned thrust bearing the eventuially you reaxh the hardened fastnet (pins or screws) and then you have damage as great as when the forward thrust bearing falls out. I also seen where people modifiy the main cap to use two bearing, but because the Triumph cam bearing have no locking tabs, like the MG thrust bearing, that means for sure they have to be pinned with his mod. Most all racer never, ever pin the thrust bearings, they just change them when tey refresh the motors. Here's my advice FWIW, keep your foot off the clutch pedal as much as you can at stop lights and red lights, holding the clutch in while the motor is running is what wear thrust bearing out, secondly, just be prepared to repalce them about every 30-50K miles, which isn't too hard, no more than we use these cars today, and I know folks with 1500 midgets that do this by dropping the oil pan.

I don't do the oil galley mods on the street engine, it does increase oil flow but for a street engne this only lower oil pressure at normal rpms, racers do this but they mantain high rpms on the track which keeps the pressure up. If you ever been to a SCCA or vintage race, ever notice that we racers tend to rev our engines as we come off track, it's not because we just can't get enough of reving our motors, it's because the oil is really hot, and most of us and done things to oiling system and clearences in the motor that makes our hot low rpm oil pressure wit hot oil go to nearly nothing, so we rev the engine until we can get them to a point to shut them off to mantain some sort of oil pressure.
 
mightymidget said:
what about shaving the head, can you raise compression on the 1500 ?
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Sure you can use a flat top psiton. If you shave the block on the 1500, you can only do a skim cut as the 1500 uses a recessed area in the block for the 1500 head gasket. Most 1500 racer use a custom piston with speced compression height that allows them to deck he recessed area of the block deck, then use a 1300 head gasket (same bore as 1500, the 1500 in creased it dispalcement thru stroke, not bore)

We used TR6 piston to achieve the same thing in SCCA limited prep engine, as for deck the recessed area out fothe block deck, the TR6 std. psiton is exaclty .040" over for a 1500, but the compression hieght of the TR6 piston is much less than the 1500, so alot of bock decking has to be done, this has been doen many times, and using the TR6 piston in the 1500 was actually thought by Triumph racing great Rick Cline, I built a couple of 1500 engine like this by using Cline recipe. The receesed area inthe block and 1500 head gasket was supposed to be a improvement and it should have been, but it has long been a trouble sopt fo these motors, so thats why people get rid of the recessed ara in the block deck.
 
recordsj said:
thanks for the info. not modifing the engine for racing, it is just for a fun car to drive.
Click to expand...

Then my advice is to use really good quailty parts, Payen gaskets, King/Vandervell tri metal bearings, good cams and quialty lifter (I like APT's cams and lifters) Hardened exhaust seats for unleaded gas. Do all the proper machine work that the engine needs, remember your eyes are not precision measuring tools, have it measured to see what needs to be done. When you get ready to build the engine, I offer engine rebuilding kits, I get most of may parts from known quailty sources, and sell them to you for the same price you can get them for, but I never found a single source for everything, so what I offer is an experiecned professional engine builder assemblying a engine rebuild kit for you using the same parts I use in my own customer engine rebuilds. The kit are not standardized, they are customized to your needs. Normally the begining point is when you have disassembled your engine and deemed what machine work needs to be done, thats the point when you are ready for parts, and I can be of assistence.
 
Hap, I think it's time for a 1500 sticky so you don't have to keep repeating yourself.


What about lock-tighting the thrust bearins in?
 
kellysguy said:
What about lock-tighting the thrust bearins in?
Click to expand...

I don't see it could hurt anything, worth a try I use in less than traditional places now like around the outer edges of seals. I still think the #1 mod you can do to a 1500 to extend thrust waher life is train one's foot to stay off the clutch at extended stop lights and stop signs.
grin.gif
 
I've been doin' that. I find myself doin' it with other cars too now. I no long push the clutch in when I start it either.

Is the 1500 really a tractor engine like I've heard, or is that just an old wive's tale?
 
Yes, that is a wive's tale. The opposite is true--a variant of the engines used in many Standard Triumph cars was supplied to the Ferguson tractor companies.

In the US the Ferguson tractors of this era were supplied with 145 ci gasoline Continental engines. I imagine the Fergusons manufactured in the UK would be of a similar size. Even geared down the 1500 would not have enough power to plow.
 
Here's a funny tractor/LBC story, years ago racing MGBs long before the introduction of gear reduction starters, with the MGB SCCA race engine getting pretty high in compression ratio, 14-15 to 1, it was not uncommon for to blow the starter drive to pieces, a wise older man came up to me after seeing one of my starter drive blow up and ask me if I had a Ford tractor place near me, which I did, he gave me a part number for a super HD starter drive to get at the Ford tractor palce, turns out some older Ford tractors used the same Lucas starter as the MGB and had the same issues and they had came out with his HD starter drive, I still have one of those things lying around in the shop. :smile:
 
What kind of specification and where do you find it to give to a shop to balance components?

I understand and wanting balanced components, but how much is this giving you in longivitiy of the engine as opposed to the components as stock?
 
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