Whats happened to me..................

[Carsreunited]

Just thought I'd let you know what's going on with my engine.<br>
<br>
As you will remember, I have had two crankshaft bearing failures in as many races which has annoyed me immensely. The first time it was number two bearing, the second time it was number one.<br>
<br>
The conclusion that has been reached, and it is something I've heard the other dolly racers talk about, is that feeding the bearings equally with oil is very difficult but is obviously something that is desirable. <br>
<br>
The 'R&D' department of Jigsaw are now looking at designing a gallery to feed the bearings. A similar thing has been done with Kev Hadfields Herald racer as he was having similar problems.<br>
<br>
Anyway, over to the forum for your thoughts on this.<br>
<br>
Scott

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[Mark Larmour]

Scott, This is not a problem we have experienced in 20 years of racing Sprints. I suggest there is some other problem which is allowing oil to bleed off before it is reaching the bearings. Has anyone checked the oil pick up tube to make sure there is no leak between the sump and the oil pump, the jackshaft front bearing for excessive clearance, the cam bearings (ditto). Is the oil pump perfect? Oil filter not starving the system? etc. Any bearing failure we have ever had has been the result of some other mechanical issue. As the failure is a different journal to last time it is obviously not a feed problem to the actual bearing journal. <br>
I would look further into the existing parts before I introduced an auxilary oil feed line- it is just one more thing to go wrong. Our bearings usually last the life of the engine - 3 seasions of racing equivalent to approx 2500 miles.<br>
<br>
Philip

<p><!--EZCODE LINK START--><a href="http://www.sprintparts.triumphowners.com">SPRINTPARTS</a><!--EZCODE LINK END--></p><i></i>

[bodgerben]

Scott,<br>
<br>
(ezboard lost this the first time I hit Add Post Grrrrrrrr)<br>
<br>
A case of starting with the easy bits first - <br>
I think I would check the block and crank before attempting to add a new oil gallery.<br>
The reason I say this, is that these lumps have done many a 24hour race, and there has been a good few racing Sprints without this sort of bearing failure (granted - there probably has been a number of race sprints with bearing damage, and this could be due to any number of things).<br>
<br>
I think the bottom end, provided it's built properly, is nice and strong, and with the bearing brace should be able to rev happily for a season with no problems.<br>
<br>
What oil pressure are you running, is the pump still spotless?<br>
Oil pick up - is it loose?<br>
What crankshaft damper are you using - the damper is only there to prevent bearing failures.<br>
Whats the history of this block? - even dipped blocks can hide grot if they have not been treated to regular oil changes.<br>
Main and big end bearing clearances - don't trust the grinder, check with plastigauge.<br>
The bearings themselves - Definately VP stamped on the back? <br>
Main bearings line bore - the crank should spin freely with all caps torqued down.<br>
Oil ways - is there a minor blockage, remove all plugs and re-clean, even if Mark did this before, do it again, both block and crank.<br>
Front jackshaft bearing, if you have any play - get it line bored and have a bearing inserted, if you have excess play here you will loose main bearing pressure, and the top end will suffer.<br>
How much heat was transfered to the crank - what damage did it suffer?<br>
<br>
<br>
A changed oil gallery is a new one on me, the main oil gallery sits directly above the mains, and the bearings receive oil before the jackshaft and cam. If the front jackshaft bearing is worn you will loose pressure to the head and the mains, if the crankshaft damper is worn - rubber perished, or out of balance you will knock out the bearings from No.1 back (not likely in one race).<br>
<br>
Taking an oil feed from the transfer housing to a spray bar above the cam is good for those using the Group 1 cams, that's the only 'additional' oil feed I have seen, also bear in mind you can easily adjust the pressure, and a race car should run with up to 100psi.<br>
<br>
Ben<br>
<br>
<!--EZCODE LINK START--><a href="http://www.dollysprint.com" target="top">www.dollysprint.com</a><!--EZCODE LINK END-->

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[SprintV8]

It's great having high oil pressure but if the quantity (Flow) isn't enought suely that's more important.<br>
<br>
I raced two years with the trusty Escort XR3 (Rookie Rod's) and only changed the Oil pump to a high flow type and didn't once suffer any Engine Failure's.(Sorry Scott didnt mean to rub it in).<br>


<p>1980 Dolomite Sprint V8.(To be MegaSquirted watch this space)<br>
1996 Rover 115 (Diesel and with a leaking displacer)<br>
2003 Suzuki GSX1300R (90mph in 1st gear Someone should of said it was 6 Speed)</p><i>Edited by: <A HREF=http://p206.ezboard.com/bthetriumphdolo ... printV8</A> at: 1/8/05 7:58 pm<br></i>

[John Skinner]

It sounds like Jigsaw are trying to blame the problems on engine design rather than your particular engine.<br>
<br>
I'd go with what other racers with the same engine type are doing - if they are not having bearing problems and you are, then the problem is with your engine, don't let them convince you otherwise.<br>
<br>
Why not get it rebuilt somewhere else? Then you get the benefit of more people's input. You can always go back to Jigsaw.<br>
<br>
<br>
John

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[dollysteve]

I agree with John, in no way would I try to discredit Jigsaw, they do some excellent work and your car (Scott) looks beautifully prepared but after 2 failures I would start to question why they haven`t got it right. Brian Kitley seems to be very highly thought of in the racing Dolly game, perhaps he`s worth a try.

<p>1976 Dolomite 1850 HL<br>
1979 Dolomite 1500<br>
1989 Mini 1340 Race Car<br>
1998 Fiat Bravo TD100</p><i></i>

[Fingers Burnt]

"Brian Kitley seems to be very highly thought of in the racing Dolly game, perhaps he`s worth a try."<br>
<br>
Out of the frying pan and into the fire.......................

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[bodgerben]

Dunno about changing the engine builder - Mark has got a very good reputation, and he's in this business to pay the mortgage - not to do people favours - remember - you don't go racing to save money, you go racing to spend money.<br>
That's not to say you cannot go racing on a budget, look at Mart and Smifter - they get their hands dirty, have fun and have had good and bad times.<br>
Scott has spent a fair few quid with Mark, but I would say even the best engine builder cannot forsee problems with a second hand block and head, unless you know the full history.<br>
Stick at it Scott, but I reckon Mark is barking up the wrong tree about the oil gallery - there can be any number of problems with the block, crank and head. Throw them away and start with a new block (I sold a new one a few months ago for £70, Robsport had a few as well) and a new head (they are about for a few hundred quid, but I ended up spending too much - just coz I could not trust all the heads I currently have).<br>
It's one thing building a Sprint lump to have a bit of fun going to Tesco's, it's a bit different making a reliable lump for racing - you need a lot of luck (I know you've had loads of luck, just not the right sort).<br>
All those who think you can bolt a few 20-30 year old bits together, a set of second hand carbs, a knackered dizzy and make and engine that makes more power than the guys in the 70's are sadly mistaken, they used new, we use old and knackered, all that says to me is the rolling road operator knows how to massage his clients egos.<br>
<br>
Get Mark to give you his TR7's engine for a while, as he builds up a new one for you - is he using it?<br>
<br>
(Its not just historic guys who make mistakes - I was at the LMES at Spa a few months ago, with a brand new Porsche 911 RSR - Porsche box broke - pidgin shit welds in it, £10K's worth of box destroyed - ok we got a new box - but the race was donald).<br>
<br>
Ben<br>
<br>
<!--EZCODE LINK START--><a href="http://www.dollysprint.com" target="top">www.dollysprint.com</a><!--EZCODE LINK END-->

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[Stephen Grellet]

This does not appear to be a common fault in the Sprint engine. I think you need to go back to square one and carefully check all dimensions, ie make sure the bearing journal diameters are correct, fit the shells to the rods and measure the diameters and compare to the crankpin size and make sure you have sufficient clearance (.002"). Make sure the oil gallerys are clear, A rifle cleaning brush is excellent for this. Check the front jackshaft housing clearance, although if you are not having valve gear problems then this could be ok, but check. Is the sump baffled correctly so that the pickup is not starved of oil. What grade oil are you running. I have used Castrol RS 10/60 with good results. Do you warm the engine oil prior to the race. What oil pressure are you running hot. Just because the Dolomite engines are 30 years old does not necessarily mean that this will cause failure, unless they have been damaged by some other event. There will be a reason that this is happening, and it will probably be simple once you have found it, finding it can be the expensive part.

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[Carsreunited]

Thanks for all the replies. Alot more questions to answer than I thought.<br>
<br>
In no particular order.<br>
<br>
1) Oil pressure was 40 psi at idle, 60-70psi at revs. Very consistent and no indication of surge, at least from the guage, and I have a big red light that comes on if the pressure goes below 30psi.<br>
<br>
2) I have to assume that all bearing clearances etc are correct at the point of being assembled. All parts were tested prior to assembly. My original block was ditched and I sourced another block from Martin which came up to scratch.<br>
<br>
3) The one race old oil pump was replaced with a brand new one just in case it had any debris in it from the first failure. Same with the oil coller.<br>
<br>
4) The sump is baffled and has wings to help retain oil at the pick up under acceleration and left hand bends. <br>
<br>
5) Crankshaft damper?? I don't have a freudenberg fitted but then I don't rev beyond 7000rpm.<br>
<br>
6) After the first failure, the crank was thrown away having suffered journal damage. Replaced with a fresh crank and re-balanced again. I have another crank to replace that one as in my wisdom I bought 2 from the same guy after the first failure.<br>
<br>
7) Having spoke to Ken Clarke, Tony Crudgington, Nigel Garrett, Ken Osborne and Paul (can't remember his surname but he raced very competitively and built his own engines), bearing failures are common on Sprints. They can be reduced. According to Paul who rigged an engine up once to mains water as he couldn't understand why his bearings were failing, he clearly saw that the front oil feeds to the mains were substantially less than what was fed to the rear. I think this is an engineering issue and I'll see what Mark comes up with.<br>
<br>
<!--EZCODE EMOTICON START 8) --><img src=http://www.ezboard.com/intl/aenglish/im ... lasses.gif ALT="8)"><!--EZCODE EMOTICON END--> I have heard stories from other racers about prominent engine builders who have had problems with Sprint race engines. Some walk away from their customers when there are problems with a shrug of the shoulders. There are no guarentees with race engines. If someone is willing to give me a 1 year 'no-failure' warranty on a race engine then please point me in the right direction!<br>
<br>
9) I'm using Penrite 20/60 oil.<br>
<br>
10) Always warm the engine and just as importantly help it cool down after a session by pushing the water around the block/rad by starting the engine every minute or so for 5 minutes. until the temps are down to 70ish.<br>
<br>
I appreciate the replies. I'll ask Mark about the TR7 engine Ben. After all if that breaks then its probably down to me. It did around 90 hard laps of Mallory with no problems whatsoever.<br>
<br>
Scott<br>
<br>


<p></p><i>Edited by: <A HREF=http://p206.ezboard.com/bthetriumphdolo ... eunited</A> at: 2/8/05 10:37 pm<br></i>

[MaddMart]

I don't think I would like to hazard a guess at what the problem is. Mine has got a std. bottom end and, although not as powerful as yours Scott, it has lasted a half a dozen or so trackdays (touch wood) plus the hundreds of miles I travelled to & from the circuits. (bet I blow my engine at the next track day <!--EZCODE EMOTICON START :rolleyes --><img src=http://www.ezboard.com/intl/aenglish/im ... s/eyes.gif ALT=":rolleyes"><!--EZCODE EMOTICON END--> )<br>
<br>
Although we realise Mark has done a lot of work on your car and looks after it for you, why not give Ken Clarke a ring. I mean he's been racing & developing Sprints for years & doesn't live far from you. Surely you can get your heads together & sort it out.<br>
<br>
best of luck<br>
<br>
Martin

<p><!--EZCODE LINK START--><a href="http://www.dolomitesprint.com/" target="top">www.dolomitesprint.com</a><!--EZCODE LINK END--></p><i></i>

[Carsreunited]

I don't doubt that Ken is a good engine builder but he has his own engine failures just as much as anyone else. It's only fair that I give Mark the opportunity to sort it out. Besides, I've paid him for the engine and don't have the money to pay someone else to say, "Oh, that's no good, I'll have to start from scratch. That's 5 grand please."<br>
<br>
I'm just glad someone is having luck with their engine Martin. I don't begrudge you the reliability!<br>
<br>
Scott<br>


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[SprintV8]

<!--EZCODE BOLD START--><strong>10) Always warm the engine and just as importantly help it cool down after a session by pushing the water around the block/rad by starting the engine every minute or so for 5 minutes. until the temps are down to 70ish.</strong><!--EZCODE BOLD END--><br>
<br>
<br>
Why not left it run for say a couple of minute's at idle after the Race ETC then just switch off.

<p>1980 Dolomite Sprint V8.(To be MegaSquirted watch this space)<br>
1996 Rover 115 (Diesel and with a leaking displacer)<br>
2003 Suzuki GSX1300R (90mph in 1st gear Someone should of said it was 6 Speed)</p><i></i>

[Mark Larmour]

Another thought on the bearing life issue. We only use Nitrided crankshafts. Early on in our Sprint racing we did have some bearing problems, but since we went to Nitrided crankshafts, all our bearing problems have disappeared. <br>
<br>
If you don't run Nitrided cranks, we would strongly recommend doing so.

<p><!--EZCODE LINK START--><a href="http://www.sprintparts.triumphowners.com">SPRINTPARTS</a><!--EZCODE LINK END--></p><i></i>

[John Skinner]

Why are you using such a thick oil? <br>
What temperature is your oil getting to during a run? <br>
<br>
Stick with it and it'll get there in the end. You'll have to hurry up though or there will be no season left!

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