The Triumph Dolomite Club - Discussion Forum

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PostPosted: Tue Dec 07, 2010 9:43 am 
Hi fellow track day Sprint users

Silver car was back at the racetrack on the weekend for one of my favourite events of the year - an event the Vintage Sports Car Club club calls the Vintage Stampede. Numbers on the car and racing!! Had a great day - knocked a second off my previous best time (amazing the difference it makes having the rear bumper of an Escort to chase rather than running by yourself!!). Ran about 25 laps, including a 10 laps as part of a relay.

About half way home, noticed that horrible tell-tale sign of steam coming from the exhaust – blown head gasket. I hadn't run any silly numbers on the temp gauge all day - probably highest 105°. This was to be this current engine's last hurrah as I have a new engine ready - much more competition orientated than this one with a girdle bottom end, fully balanced, new Neuman cam, 45 Webbers, etc so I'm slightly annoyed the old one blew the gasket, but it was coming out anyway.

I've no doubt this has come up many times, but I want to know what you guys think are the best preventative measures, given we all know the Dolomite has a considerable reputation for head gasket failures. On the new engine, I will be torquing the head down before all competition events. I didn't do that with this engine for this event or the previous track day - a mistake? Is it considered a worthwhile mod to run cooling to the back of the head? I believe this is a hot spot. Where do you pick up the cooling? The car will not be running the heater, so I am assuming this outlet direct to back of the head? Any thoughts and experiences welcome as I want (and need) the new engine to stay in one piece for a long as possible.

Thanks

Paul Roberts
Perth, Western Australia


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PostPosted: Tue Dec 07, 2010 9:44 am 
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Joined: Tue Oct 03, 2006 10:57 pm
Posts: 5154
Location: South Coast
trackerjack did a post on this.....i'll have a look

There are two. One is here viewtopic.php?f=4&t=11284&st=0&sk=t&sd= ... ad+failure

The other is entitled overheating the cure.

Neither contain all the info I was looking for but it is possible Jon told me the info rather than wrote it down....

It would be interesting to see what type of gasket is on yours Paul

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Previous owner of 42 Dolomite shaped vehicles, 14 Sprints, 12 1850s, 8 1500s, 3 V8s, 3 Toledos and 2 SEs


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PostPosted: Tue Dec 07, 2010 11:34 am 
The sprintparts headstuds with the fine thread and dowel the engine and head.

Jeroen


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PostPosted: Tue Dec 07, 2010 6:42 pm 
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Joined: Fri Nov 23, 2007 11:33 pm
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Location: hampshire
Over a a time of 19 years using sprint engines I have blown head gaskets about 6 times (remember I do many track miles)
they always have blown between no 4 cylinder and the top large waterway, so for the last engine I have used a centre pot and peppered the alloy head (outside the steel fire ring on gasket) to give the gasket more grip.
Payen gaskets are stronger in the steel fire ring than some and I have yet to blow a Payen (I never knew the difference till recently).
Never ever give it stick until the engine is hot as the alloy has to expand to increase the clamping pressure.
When I owned a V8 MGB the exhaust manifold would be noisy and blow until the engine expanded and shut it up :shock:

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The lunatic is out................heres Jonny!


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PostPosted: Tue Dec 07, 2010 11:12 pm 
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Joined: Fri Oct 06, 2006 9:57 am
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Location: Auckland, New Zealand
In over 10 years of racing and well over 60 events I have only ever blown a couple, even when usung a double thickness gasket. I always use Hylomar -the blue jointing compound and torque down before every meeting.

Biggest improvement I made was fitting a s/h Porsche 944 alloy radiator - just fits the gap, hose connections in the right place, easy to fit, inbuilt thermoswitch to run the electric fan. I have never managed to get the temperature above 95 degrees since, even on scorching hot days.

I always warm the engine up well before racing - get some temperature in to the oil as well as water - and then let the engine idle with the electric fan on at the end of each race to ensure there is no localised overheating - bigger alloy radiator really helps here.

I use rain water with a water wetter containing corrosion inhibitor - never antifreeze.

Geoff


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PostPosted: Wed Dec 08, 2010 4:48 am 
As my friend Jeroen alredy mentioned, good fasteners and doweling, but how to do that?
Look at some of the pictures in my foto site . Go to Smugmug. http://sprint.smugmug.com/Cars/Fast-roa ... 4456_cczN4.
Told this before, during all the time i'm building Sprint engines never ever I had a blown head gasket using this doweling technic. An other importand part is to use the original Elring gasket, very dificult tu get now.
The corect torque sequence, and top quality cooling flued, like original Toyota not the cheap stuf, I prefer to use Demeneralised water treated with so caled waterweter by Redline from the USA.

Greets from a warm Florida right now, we are here to visit the PRI show in Orlando, no Disney or whatever, but PRI mean Profesional Racing Industry, it will benefit the Sprint engine, this time we are after new valves technik.

If you feel like it contact me when we are back home in a week.
Hans


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PostPosted: Mon Jan 17, 2011 9:29 pm 
My sprint has never blown a head gasket in 22 years racing. I have opened up the water ways into the head, I have competition studs torqued to 65ft/lbs on the angled ones & 60ft/lbs on the straight ones. I slacken & retorque them individually before each event. My head is not dowelled to the block as this is only necessary when using over 8,500 revs/min regularly. It is very important to allow the car too cool slowly so I always cool it down on track so as to not get any heatsink through the engine as this can cause more damage to the head gasket than continued running.


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PostPosted: Tue Jan 18, 2011 12:45 am 
How do I have to reed this, regularly over 8500 rpm??
I mean what kind of cam for a sprint engine want 8500rpm, the engine is already for a long time running on the down slope of the power curve.

Roughly in a well setup car the RPM difference between the gears is about 1500 RPM or even less
Now going to the next gear you go to about 7000RPM and pick up in the down slope of the power curve, instead of picking up power.
You will need a heavily modified bottom end also, the flex of the main bearing casting will not stand up for long, this is just nonsense.

Next to keep the head in the right position to the block, it also ensure that the gasket is in the exact position.
This all give the possibility to line out the waterways including in the gasket, that these 3 parts (block gasket head) indeed after assembling exact in line.

For the people who doubt this, just put a head on a block and find out how far the head can move over the block without any form of making a fix location.
The same for a gasket, put it on the block with the fasteners in and look how far the fire rings can be off the centre of the bores before the fasteners prevent for further moving of this gasket.

Hans


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PostPosted: Tue Jan 18, 2011 8:29 am 
So you are saying I have been doing it wrong for 22 years! Well I have one many races in that time, I have only ever blown 1 engine, this was due to the ball bearing on the blanked gallery of a X drilled crank coming loose. I have built many other race engines which all rev to 8,000 rev/min +, my engines produce around 200 BHP @ the wheels, I think I will keep doing what I am, it works well. Incidentally Nigel Garrett who is probably the most successful Dolomite racer in the UK if not further afield also uses in excess of 8,500 rev/min. Will you tell him he is wrong or shall I?


Last edited by Dolly racer 33 on Tue Jan 18, 2011 8:53 pm, edited 1 time in total.

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PostPosted: Tue Jan 18, 2011 5:14 pm 
Dear Sprint racer 33

Wauw, it seem the new rules for this year are offencive language, actually don't think that this new rule is very constructive at all, liked it more as it was before.

Coming back to your first post your telling; My head is not dowelled to the block as this is only necessary when using over 8,500 revs/min regularly.

So I could have seen it that in your words we where wrong by doweling a head in a professional way.

I came with the question what Sprint cam will need 8500 RPM you even name it regularly.
Now you come up with "up to 8000 RPM" in my view a big difference.
I suspect that you also have seen on the (your) dyno that at 8000 RPM the power is into a down slope for a while, at least with the sprint cams I know, and measured on my dyno.

To be honest I absolutely don't like the remarks about Mr Garrett that I have to tell him he is wrong.
For a start we have always respected that driver, even that much that we have been over to the UK several times in the early 90' to see him race. (there is still a video of 2 different races of him in my foto site, just have a look http://sprint.smugmug.com/Cars/Forum/11 ... 7799_XbRL6
Feel free to contact Mr Garrett, and tell him that we have enjoyed the races we have seen him driving his green Sprint.

BTW Even with my now over 30years of experience with this engine, (and still learning, see our new projects) you puzzled me a bit by telling that a blanking ball was coming out of your racing cranks??? in combination with this obvious high RPM

Very silent now, (I don't dare to advise) we always have replaced them by scrub screws.

Regards

Hans

--
Hans ten Broeke
De Hoge Esch 49
7783 CB Gramsbergen NL


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PostPosted: Tue Jan 18, 2011 8:25 pm 
Hans, I think it is you that is offensive by saying that my previous post was nonsense.. I did not say you were wasting your time professionally dowelling your head I was replying to a post about a blown head gasket. The car is used for track days & with a standard bottom end probably only uses around 7,000 rev/min. In my opinion based on over 20 years experience building road and race engines for the Sprint for this use it is an unnecessary expense to dowel the cylinder head.

I did not say up to 8,000 rev/min I said 8,000+, not everyone i have built engines for wishes to take them to 8,500 rev/min.

You said I was talking nonsense reving my engine to 8,500 rev/min. I merely pointed out that Nigel Garrett also uses in excess of 8,500rev/min therefore according to your logic he must also be wrong.

I am not 'very silent now' the ball bearing in question came out in 1990, probably because I was needlessly using 8,500 rev/min, I replaced the ball bearing with grub screws then & have done ever since.

I am not questioning your ability or saying that what you do is wrong. I would ask that you afford me the same courtesy.

Ken Clarke.


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PostPosted: Tue Jan 18, 2011 9:08 pm 
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As some of you will know we work with both slant 4 engines - the Sprint & Vauxhall - I have been involved with Sprints for over 30 years too. With a block ladder/Don Moore type block, well over 8,000 is achievable on the Sprint. I too have never needed dowels on Sprints and have never had a head gasket go on any Sprint I have owned (..and I lost count at 50 cars!). We do use dowels on the Vauxhall block and strapped mains, but there we achieve 8,500 or more with steel crank, 11:1 compression, etc. I am usually interested in Rallying, so out-and-out BHP at the top end is not always what we want, more a fast high torque curve which lasts, which invariably means playing with cam durations, timing, etc. The Vauxhall engine is 300cc bigger of course. The main problem with both these engines when compared, to say a BDA, is the rotational dynamics caused by the slant mounting, often upsetting induction. My works Sprint is producing about upper 190's bhp, but with oudles of torque lower down. Of course there is also the interchangeability of parts to consider - the more modifications, then the more specialist, etc. I have one of the Cosworth pistoned dry sumped engines to rebuild and no doubt will spend a small fortune bespoking to do so, but that's the game! Personally, I think both approaches are valid and neither are right nor wrong, but I can attest that Ken's ways do work. ANyway - that's my two penneth - so light blue touch paper and retreat! :smooch:


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PostPosted: Thu Jan 20, 2011 2:59 am 
Hi guys

Firstly, thanks for all your replies and thoughts re my blown head gasket. As always, I very much appreciate the shared information from the users of this forum. I think the major thing I have taken from this post is that a) blown head gaskets are avoidable (several racers said they had never had the problem) and b) retorquing the head before all events is probably my best solution to avoid the problem. I also have to say that I have found the passion expressed by Ken and Hans to be great. There's obviously more than one way to approach a problem and both of you have obviously been very successful in producing fast, reliable and strong engines. Keep up the good work and never lose the passion.

Cheers

Paul Roberts
Perth, Western Australia


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