Austin Seven Failures and How To Avoid Them
PART 1 - THE SEVEN ENGINE
Click here for part 2 - flywheel, gearbox & clutch
Click here for Part 3 - Propshaft & Real axle
BROKEN CRANK
* Crack Test
* Line Bore 3 Bearing
* Fit Phoenix
LOOSE FLYWHEEL
* Riding On Key
* Fit Out Of Engine To Ensure Oil Thrower Clearances etc.
* Lap Onto Taper
* Really Tight – Use Impact Driver with a 3/4" socket/bar on flywheel. Think about Loctite
OIL PUMP
* Vanes: Flats go on bottom
* Check pressure release is clean & not rooved
* Check springs
* Make sure gear on very small key
* Loctite gear nut
Front bearing lip broken
* careless bearing removal
* trying to fit wrong bearings
* inspect carefully for cracks
* replace ring – Vince does them.
Split cam followerS
* difficult fault – misfires at high speed –sticks in guide
* check before fitting
* avoid over tightening (& under tightening!)
Sheared studs
* what made of ? – EN36? Dave Cochrane uses EN16t
* beware cheap
* leave good original alone
* use Studlock
* avoid over tightening
* helicoil if slack
Front camshaft bearing
* replace peg with 5/16 bolt with washer (tap bearing in situ)
* can use socket headed screw
Head gasket
* flat surfaces
* no corrosion
* assemble with grease smeared on
* ensure correct gasket (HE or LC)
* can be either way up (usually seam up)
* torque to 20 ft lbs in correct sequence
Oil leak rear main
* modern lip seal on smooth surface or use speedy sleeve repair
* worn out Quickthread
* loose rear main
* oil thrower missing/ wrong way round /not crimped
* oil return hole not lined up in carrier
* three different flywheel boss sizes (so use lip seal!)
* make sure seal casting is drilled correctly
Split crankcase due TO little end bolt
* use new HT bolt with spring lockwasher & Loctite
* use internal stainless shakeproof
* loose bolts split 1 in 12 conrods
blocked oil jets
* change oil regularly
* beware multigrade detergent oil unless oilways scoured out
* use monograde oil
* use oil filter if doing high miles
Broken top water manifold bolt
* use stainless stud
* inspect carefully – make sure not cracked strap (use nut under?)
* tighten carefully
Broken side manifold bolts
* same as top
* when repairing do not drill/tap into bore
* use hacksaw blade as drill stop
Cracked block
* watch out for sludge around bottom of bores
* watch out base of no. 4 bore can be thin when sleeved
* change block if cracked from centre stud
I hope you find this useful, Phil Whitter