Dilemma

plastic orange · Post by **plastic orange** » Mon Aug 22, 2011 6:31 pm

I've posted a few times regarding an ongoing tappit rattle from my 3.9 engine in my minor. I'd thought that fitting a new cam and lifters would have cured it, but after a 250 mile run yesterday I'm pissed off. It drove perfectly fine with no noise when held to about 3000 revs, but when I upped the pace it started rattling. It did go away after a short while, but intermittently came back on my journey. At one point it was sounding like the turbo diesel in my mate's minor van.
The engine has had this rattle since I fitted it, but I think it's worse with the Hurricane cam fitted. So far I've done the following:
New composite head gaskets with 25thou off heads to compensate, new valves, springs, oil pump gears, new relief valve, rockers and shafts, cam, lifters, timing gear and chain. In fact everything apart from crank grind and new rings. Engine is clean as a whistle inside, doesn't smoke or use oil, and ticks over smoothly until rattle starts. It's definately not exhaust leak before any one asks

I really think that it's just not getting enough oil to the top end, but I've poured oil down both rocker feeds, and when heads were off poked thin wire down the oilways. When I was priming the pump after cam fit, there was a steady flow of oil out the oilways, but not as strong as i would have liked. I feel I could almost run with the rocker covers off and not see much oil spray.

SO, do i look for another engine as I don't feel confident that a full rebuild would solve my problem?

Cheers

Pete

ChrisJC · Post by **ChrisJC** » Mon Aug 22, 2011 7:34 pm

I have run with the rocker covers off, and you don't get any oil spray, not at idle anyway. You just get a trickle out from beside each rocker.

Could it be a dodgy little end?

Chris.

Darkspeed · Post by **Darkspeed** » Mon Aug 22, 2011 7:52 pm

Whats the spec on the heads?

Andrew

plastic orange · Post by **plastic orange** » Mon Aug 22, 2011 9:50 pm

Darkspeed wrote:Whats the spec on the heads?

Andrew

Heads are standard 3.9 with 25 thou skimmed to use composite gaskets.

Pete

minorv8 · Post by **minorv8** » Tue Aug 23, 2011 5:01 am

I have occasionally the same issue. I have had problems with lifters, especially when cold. 20W50 oil in cold mornings do not exactly help. Mine is more, like tapping noise, not rattling. When it was rattling more, I shut down the engine, took the valve covers off, rotated each piston at TDC and checked whether there was any valve clearance in the lifters. It´s easy to check, just twist the rocker arm against the pushrod to see if it gives in. I had some suspect lifters so I replaced them last winter. I still have occational tapping but have chosen to ignore it...

ChrisJC · Post by **ChrisJC** » Tue Aug 23, 2011 7:06 am

Also did you measure piston-bore clearance on all bores?

Chris.

plastic orange · Post by **plastic orange** » Tue Aug 23, 2011 7:44 am

I've never measured piston/bore clearance, but all bores looked pretty fresh. Compression check was up to spec as well. I suppose the rattle could be described as tapping - sounds like very loose tappits when it happens. However, it is quiet when I fire it up first thing, and does go quiet again after the noise has been evident for a bit. I'll post up videos of the noise.

Pete

plastic orange · Post by **plastic orange** » Tue Aug 23, 2011 7:57 am

Here's some vids of my engine from a few weeks ago in reply to another thread. It sounds quiet until it's revved hard, then ticking starts. It will disappear, but comes and goes randomly, but since new cam fitted it will always do it when revved hard.

Just back from a short run

Been ticking over for a short while

Revved to 5.5k

kiwicar · Post by **kiwicar** » Tue Aug 23, 2011 7:59 am

Hi
Collapsed piston skirt? whip the sump off and look from below?
Best regards
Mike

plastic orange · Post by **plastic orange** » Tue Aug 23, 2011 8:14 am

Sump off is engine out - looks like this will be happening one way or another.

Pete

DEVONMAN · Post by **DEVONMAN** » Tue Aug 23, 2011 8:51 am

Pete,
Have you fitted shims under the rocker posts?
Some shim kits have oil feed holes in only 2 of the shims and these need to be fitted at the front posts.
Cheers Denis

plastic orange · Post by **plastic orange** » Tue Aug 23, 2011 9:11 am

The shims had 3 holes in them.
The thing is, this engine had this ticking noise when I fitted it (I didn't discover this until I had my first long journey). I don't know the history of the engine apart from it came out of a smashed Range Rover. Apparently it ran well, but the engine was removed from the vehicle as it was too badly damaged to be repaired. It lay outside under a cover for a good few years before i got it (was only £100).
The 3 video clips are from before I fitted the shims. I'll post up some more videos later today.

cheers

Pete

JSF55 · Post by **JSF55** » Tue Aug 23, 2011 9:39 am

You could try the trick my dad used too do with rattley crossflows and remove one cover at a time and and slip a feeler gauge under each rocker arm and see if it goes quieter ? won't do the feeler gauge any good

DEVONMAN · Post by **DEVONMAN** » Tue Aug 23, 2011 11:07 am

It does sound like top end to me but as you have no history regarding the bottom end the following reason for the noise is possible.

The RV8 engine has 2 oil galleries which feed the followers. On one side of the engine the gallery also feeds all the main bearings which in turn feed all the big end bearings. When the mains and bigends are well worn, the oil pressure feeding the followers falls off at the rear of the gallery due to losses into the bearings. Fitting the Hurrican cam would have increased the pushrod load slightly and low oil pressure at the rear of the gallery may be allowing the followers to bleed down slightly when they are working hard. The noise actually sounds like you have Rhodes lifters, hence my thinking.

Just a possibility.

Cheers Denis

plastic orange · Post by **plastic orange** » Tue Aug 23, 2011 5:25 pm

Large Shims:

small shims