FOR EV­ERY owner there comes a time when the ‘hobby car’ de­vel­ops a se­ri­ous, cash-ab­sorb­ing con­di­tion and a de­ci­sion has to be made. Do you step away or step up? Cliff the Im­pov­er­ished was re­cently faced with just such a choice and elected to fund a heart trans­plant for his Tri­umph. Here is the tale. Have your hanky ready.

Reg­u­lar read­ers might re­call an OurCars comment a few months back which sug­gested that trans­form­ing the Tri­umph into any kind of a dirt-track per­former was go­ing to take some ex­treme mea­sures. Well, the task turned out to be tougher and more costly than an­tic­i­pated.

Push­ing hard to im­prove my times on the tight IWMCC dirt lay­out along­side Queensland Race­way re­quired low gears, full

throt­tle and lots of revs. Im­prove­ment did come but at the price of el­e­vated en­gine tem­per­a­tures, a mis­fire and some symp­toms of fuel star va­tion.

Dif­fi­cult start­ing and mis­fir­ing a few days af­ter the car’s last com­pet­i­tive out­ing led to a com­pres­sion test and the ugly rev­e­la­tion that two cylin­ders were lag­ging well be­hind the other four.

They weren’t even ad­ja­cent to each other ei­ther, rul­ing out head gas­ket fail­ure. Other pos­si­bil­i­ties in­cluded ran­domly bent or burned valves, but a more se­ri­ous sce­nario was also pos­si­ble.

Michael Collins at Scor­pion Of­froad in the Bris­bane sub­urb of Ca­pal­aba sug­gested a cylin­der leak­age test and quickly con­firmed the di­ag­no­sis. Cylin­ders num­ber two and four were just not par­tic­i­pat­ing, with com­pres­sion at less than half the ac­cept­able range. This was also a likely cause of ab­nor­mal crank­case pres­suri­sa­tion and oil leaks that had de­fied ev­ery rem­edy.

Off came the cylin­der head. It had been re­con­di­tioned shortly be­fore the car was pur­chased in 2016 and was still in fine con­di­tion. Mi­nor re­lief only, be­cause lower down the news was more dire. When re­moved, the crank­shaft dis­played wear on all of its jour­nals, re­quir­ing a grind and new bear­ing shells.

“With an older en­gine it’s hard to pin-point one cause for fail­ures like these,” Michael said. “High revs, over­heat­ing and ex­ist­ing wear all do their part but we don’t dis­count some­thing like fuel star va­tion ei­ther. Lean mix­ture at high en­gine speeds can very quickly cause dam­age.”

Given that sev­eral of the pis­ton rings had cracked as well, the cylin­der bores were in re­mark­able con­di­tion. When mea­sured prior to or­der­ing new pis­tons they were found to be stan­dard di­am­e­ter as well – ex­tra­or­di­nary in an en­gine that had been in ex­is­tence for over 40 years and done at least 125,000 kilo­me­tres.

In ad­di­tion to a $600 spend on new en­gine in­ter­nals there were new hoses from my stock of spares to be in­stalled and a set of shiny brass Welch plugs. These are a snack to fit with the en­gine on the work­shop f loor, a bug­ger when all of the an­cil­lar­ies get in the way.

One out­lay that wasn’t planned was a brand new starter mo­tor for an ad­di­tional

cost of al­most $500. How­ever the dif­fer­ence be­tween it and the very tired Tri­umph orig­i­nal is dra­matic.

With ev­ery­thing bolted to­gether and wheels back on the ground, all was still not rosy. A vibration that man­i­fested an­noy­ingly at around 2200rpm and was present in ev­ery direct gear (but not over­drive) needed to be tracked and elim­i­nated.

Michael was con­cerned that the shud­der was due to f ly wheel im­bal­ance but con­sult­ing the in­ter­na­tional ‘Big Six’ Tri­umph brains trust saw fin­gers be­ing pointed at the trans­mis­sion mount. Al­though brand new and from a well-known UK sup­plier, these mounts were ap­par­ently renowned for poor qual­ity and be­ing a source of vibration.

Spend­ing $106 had a lo­cally-made Mackay mount quickly headed Michael’s way. Once the old one was f lung in the scrap bin and re­placed the vibration mirac­u­lously dis­ap­peared. Sadly a few months later and af­ter a cou­ple of thou­sand kilo­me­tres, one front mount split en­tirely and the other was show­ing signs. Both were re­placed by lo­cally-made mounts.

The process of run­ning in a re­built en­gine may pro­voke ar­gu­ment and con­tro­versy, how­ever Michael and I had no conf lict as to our pre­ferred tech­niques. Easy ac­cel­er­a­tion with up­shifts at around 4000rpm, not al­low­ing the en­gine to labour and keep­ing a close eye on tem­per­a­ture and oil warn­ing de­vices are es­sen­tial.

“Don’t be afraid to use the over-run ei­ther,” Michael ad­vised. “Down­shift­ing so the en­gine slows the car on com­pres­sion is a use­ful and low-stress way of bed­ding in new com­po­nents.”

Three weeks of run­ning in


saw the car side­lined again by a to­tally un­re­lated fail­ure. The clutch re­lease fork – which I had fail years ago in an ear­lier­model Tri­umph – de­cided to fall to bits overnight while the car was parked in my drive­way. Gear­box out, fork re­paired, pigg y bank look­ing anorexic again and we were on the road.

Once the en­gine is run in and op­er­at­ing as it should un­der nor­mal road con­di­tions, a date with the chas­sis dy­namome­ter will be booked. A few hun­dred dol­lars worth of dyno time will look at fuel de­liver y rates and mix­ture and show at which point in the rev range the power falls away.

That will help with the next steps to­wards track-ready prepa­ra­tion; a car­bu­ret­tor re­build and re-jet to en­sure the new en­gine is well sup­plied with fuel at high revs and some taller tyres to help com­bat over­rev ving.

Hav­ing the carbs are off be­ing re­con­di­tioned will be a good op­por­tu­nity to wrap the ex­haust man­i­fold in high-tem­per­a­ture tape. This mea­sure has be­come pop­u­lar with own­ers in the UK who run their 2500s in his­toric rally events. Some were suf­fer­ing fuel va­por­i­sa­tion when the cars sat idling for ex­tended pe­ri­ods and the tape pro­vided a no­tice­able im­prove­ment. Might not work, but it can­not hurt.

02 Knock, knock knock, it’s time for a tow. 02

03 The head was checked and given the thumbs up. 03

05 New Pommy parts. 05

01 01 Ban­ished to the el­e­ments and wait­ing for a new heart.

04 Prepped and ready for the sur­geons to be­gin the trans­plant. 04

01 01 Ready to fire and the tim­ing is spot on.

0303 The Tri­umph’s all­new heart is ready for in­stal­la­tion.

0202 Loads of shiny new parts for the new heart.

0404 Twin SU carbs wait pa­tiently for re­unit­ing with the en­gine.

0707 The hole has been filled and its not far from start­ing.

05 05 Dizzy was blamed for start­ing woes but wasn’t the cul­prit af­ter all.

08 Sign says Subaru but they are kind to other needy breeds. 08

0606 Life sup­port sys­tem for halo­gen lights.

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