Sustained cruising speed.

[Philip]

Hi, in a 1.3 MK1 Marina, what is an acceptable cruising speed? 50mph is 4000rpm which is rather high. I feel happier doing 45mph but on the motorway, that is rediculous! What do others do in their 1.3's speedwise? My other classic, a Rover which is twelve years older will more than happily cruise at 70mph and you cannot even hear the engine! I read on another thread that you can get an alloy rocker cover for a B series and that quietens things down considerably. Can you get such a thing for an A series? Also, I have that section of soundproofing on the bulkhead missing.

[jiversteve]

I was once asked how to make a B series quiet. I'm afraid my answer was to turn it off.

Seriously though the B and to a slightly lesser extent the A suffer from cam/rocker noise.
Any wear in the system will result in clattering tappets. The only real solution is to fit a tufrided rocker shaft and new rockers but even then when cold it will clatter a bit and then quieten down as the engine heats up and the tappet clearance closes up.

Alloy rocker covers simply deaden the sound and can be got for an A.
Refitting your sound deadening material on the bulkhead will help but you might consider some new deadening material on the underside of the bonnet.

But whatever you do its still worn and badly adjusted rockers that are making the noise and anyting you do to mask the noise is not sorting the basic problem.

[Philip]

Hi Steve, what is a tuffrided rockershaft?

[jiversteve]

In simple terms (and thats difficult) a standard rocker shaft is chemical/heat treated using ammonia and hydrocarbons to give it better resistance to the wear of the rockers. It is similar to a process called case hardening where only the surface of the steel is hardened but the core stays unaffected.
The rockers do not rotate around the shaft but only move through a few degrees back and forth. As a result the shaft usually wears on its underside where the maximum load is.
If you take your rocker shaft off it is quite probable that you will see/feel ridges where the rockers have worn into the shaft.

[locost_bryan]

Hi, in a 1.3 MK1 Marina, what is an acceptable cruising speed? 50mph is 4000rpm which is rather high.

A 1.3 with the standard 4.11 diff and 145/80x13 tyres should do 64mph at 4000rpm. 50mph is about 3200rpm. 60mph is about 3700rpm - should be fast enought for the "slow" lane on the motorway.

[snowy]

Unless you pull a heavy trailer or have lots of steep hills you could change the rear axle ratio to something a little more suitable to todays roads.

[Gee tc]

HI
On our old LE (RWM 660T) we would regularly take it over to Yorkshire from Liverpool via the M62 in all weathers
where my younger brother went to school. Six to eight times a year for 4 years.
It involved a 240 return journey and a trip up and back down the 1 in 4 Sutton bank fully laden.
Cruising at 65 mph ish wasnt a problem but yes a little noisy. The only problem I recall seemed to be the gear lever buzzing!!
Loud stereo fitted and problem gone.........
The car stayed in the family for 10 years and was seviced by the book and lasted on the original engine and box 100k with no major problems or oil consumption. Seem to recall that its only appetite was for exhausts until a Kwikfit Stainless jobby was fitted.
A couple of sills were put on professionally as the sill strips had caused rotting where they were secured and this at the TOP of the sills!
It did wander a bit on the very high gusty winds going over the top of the M62. An Ital front spoiler was fitted which helped immensely.

T

[Philip]

Thanks for that. Was that a 1.3? I think I need to get that bulkhead insulation fitted mine is very loud at anything over 50.

[JubileeNut]

Yep, a 1800cc is just as bad at speed but I did 65 to 70 back from Yorkshire 315 miles, just meant I could not hear my son or wife Oh and the stereo

[locost_bryan]

Yep, a 1800cc is just as bad at speed but I did 65 to 70 back from Yorkshire 315 miles, just meant I could not hear my son or wife Oh and the stereo

The 3.6 diff in the 1.8 drops revs by about 500rpm at 60mph - should be a wee bit quieter, and sip a bit less fuel.