Sprint motor detonation

[Marsu]

I'll report what I find when I've got it out and taken the head and sump off.

My guess is I'll find a top end issues; broken pistons or valve gear.

I'm hoping there's not bottom end failure.

[Troy ODoherty]

Hi Marsu what did you find inside the Sprint engine?

Cheers Troy

[Marsu]

Hi Troy,

Sadly, the engine is still in the car due to space, time and financial constraints.

Due to the space restrictions I need a replacement ready to fit before I can pull the broken one out.

I found that both spare blocks I have for rebuilding need re-bores and oversize pistons. The cost of new pistons is outrageous so I've been looking for alternatives.

Because my pockets are a bit empty to pay for parts I've been selling things I don't need on ebay. This has involved sorting through boxes and boxes of parts I've accumulated over the years - a good thing, but takes more time than I thought it would.

Hopefully in the next few weeks I'll have accumulated the funds needed to get the Wedge going again.

I'm strongly leaning towards doing a V8 conversion as I already have the subframe, bellhousing, shortened remote shifter and some other RV8 bits.

I'll update the forum once I start the next steps.


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[Marko]

you can pull the head off while the engine is still in the car, try to find out what exactly has gone wrong before you start to buy parts.

[Marsu]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Marko</i>

you can pull the head off while the engine is still in the car, try to find out what exactly has gone wrong before you start to buy parts.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
True, I could pull the head now, but from experience, it is much easier to do when the engine is out and you can squat around it or put it on a stand or bench and not have to bend over at all.

The other reason for leaving it in place now is that the car is parked outside, rather than under cover, and I prefer not to expose the bores further until it is so.

It isn't important to me to know what broke at this stage as a replacement engine will be fitted. My options are 8V, 16V or V8.

I have a good spare 8V I could put in now and would only need to make exhaust mods - but I know I won't be happy with performance. It would be going back to where I was with a Wedge 15 years ago.

I have a good spare 16V head ready to fit but I'm only considering fitting this to a rebuilt short engine. I want that sort of security - hence the arsing around regarding over-sized pistons for the spare sprint blocks. Further, if I'm fitting a Sprint again I want to replace the ignition with EDIS and MS so that I can perhaps do EFI at a later date.

But to be honest, given I have the RV8 subframe, bellhousing, etc., the sums are adding up in favour of leaving the Sprint engines under bench and getting the V8 experience - something I've never had.

[Marko]

i thought that was your only engine.

[Marsu]

In many ways it would be simpler if it was. [:I]

I do appreciate the advice from all on this forum. [:)]

[Hasbeen]

Hi Marsu, my favourite Triumph specialist in Brisbane told me a while back that he was modifying a Mitsubishi piston for both Sprint & 8V engines.

He reckoned they were not only stronger, so possibly a performance model, but much cheaper.

I didn't get any more info than that, but I know he was looking for higher compression in some engines he was building, so the gudgeon to crown height must have allowed this to be achieved.

Hasbeen