Top end rebuild

Did you use Loctite on bolts 11 to 14 ?

I must read about checking prelaod as I have never understood why the tappets don't just automatically reset. I can see the pushrod needs to reach the cam follower when the valve is closed otherwise you'd get the effect of too wide a gap
 
The combination of skimming the head and using composite gaskets should leave the preload within acceptable limits, problems arise when things are taken out of normal limits when skimming, or cam lobe profile changes.
 
I understand the theory behind preload being too high, resulting in the valves not closing properly, but what if the preload is too low and the valves don't open enough? Can that happen? I doubt there would have been shims added at the factory that you could remove would there?
 
testrider said:
I understand the theory behind preload being too high, resulting in the valves not closing properly, but what if the preload is too low and the valves don't open enough? Can that happen? I doubt there would have been shims added at the factory that you could remove would there?
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I'd say its possible - if, say, you replaced the tin head gasket with a comp one under an unskimmed head. Also, variations from standard in the camshaft base circle, the followers, and/or the pushrods could cause it. If so, I'd say the valve train would be rattling as the tappet came off the nose of the cam. If there's no preload at all i.e. clearance between the pushrod end and its seat, the seat will be loading against the tappet circlip which could fail.

To get round this you'd have to machine either the bases of the rocker shaft pedestals, or their seating pads. Or use adjustable pushrods.

Fingers crossed for me! :)
 
DaveHerns said:
Did you use Loctite on bolts 11 to 14 ?
Click to expand...

Hi Dave,

No, I used a smear of copper-loaded Never-Seez from work. I'll keep an eye on them once the engine's up and running but, interestingly, quite a few of the guys on the V8 Owners Forum even leave these four bolts out completely. And of course Rover themselves designed them out on the later 4.0 & 4.6 heads.
 
Stan

I bought a shim and push rod kit from RPI.

I had the original heads skimmed and used composite gaskets. I checked the pre-load which was quite a bit out. When I fitted the shims it brought the pre-load to the correct figures quoted. people often say "for all it cost" and they are right, why spend a fortune on a new cam and rocker and leave the pre-load out of spec for £20. Also very easy job to do just remember to fill the followers with oil first.

I refitted the outer bolts but left not fully torqued up. Did you ever read the history of the V8? one of the yank models had an extra row of bolts on the push rod side of the cylinder head which gave 6 bolts around each cylinder, with this bolt deleted from the casting it left the 5 bolts, It makes sense that 4 evenly space bolts per cylinder is better . Though you've got to wonder how much of a problem it really was though, for all the V8 models built how many actually blew a head?

last week I started the engine for the first time since I did the top end rebuild, sounds awesome but I only ran it for a few seconds whilst setting up the distributor.

Here is a question maybe Harvey can help with. A guy I work with has rebuilt many V8s mostly for boats. When I told him that I had did some top end work he thought I had to run the engine at 2,500rpm for "x" period. Is this the case or was it just to get to oil pumping round?

Colin

4715645439ba496492a058d4123f1842d82ccbacacbfb5bf29f8e33b76d64dc2e9562942.jpg

shim under the pedestal
 
Hello Colin,

Once a new camshaft and lifters have been fitted to an engine, it is normal practice to run the engine at 2000 to 2500rpm for 20 mins or so, varying the revs during this time so as to bed in the new camshaft and lifters. The engine during this time must not be allowed to idle.

You would circulate the oil throughout the engine prior to starting by removing the distributor and using a special tool on the end of an electric drill, engage the oil pump with the tool and circulate the oil.

Ron.
 
arthuy said:
Stan

I bought a shim and push rod kit from RPI.

I had the original heads skimmed and used composite gaskets. I checked the pre-load which was quite a bit out. When I fitted the shims it brought the pre-load to the correct figures quoted. people often say "for all it cost" and they are right, why spend a fortune on a new cam and rocker and leave the pre-load out of spec for £20. Also very easy job to do just remember to fill the followers with oil first.

I refitted the outer bolts but left not fully torqued up. Did you ever read the history of the V8? one of the yank models had an extra row of bolts on the push rod side of the cylinder head which gave 6 bolts around each cylinder, with this bolt deleted from the casting it left the 5 bolts, It makes sense that 4 evenly space bolts per cylinder is better . Though you've got to wonder how much of a problem it really was though, for all the V8 models built how many actually blew a head?

last week I started the engine for the first time since I did the top end rebuild, sounds awesome but I only ran it for a few seconds whilst setting up the distributor.

Here is a question maybe Harvey can help with. A guy I work with has rebuilt many V8s mostly for boats. When I told him that I had did some top end work he thought I had to run the engine at 2,500rpm for "x" period. Is this the case or was it just to get to oil pumping round?

Colin
Click to expand...

Hi Colin,

I'm hoping I won't need to get into shimming, but if so I've got plenty of steel shim at work in varying thicknesses that can be put to good use! And you're right..if it needs doing, it needs doing.

I didn't know some yank V8's had 6 bolts per cylinder, but I did find a web page some time ago describing the Buick 215 that makes an interesting read.

1961 New Buick Aluminum Engine

Ron & your guy that works with boat engines are both quite right. The engine mustn't be allowed to idle for the first 20 minutes or so with a new camshaft. 2500 rpm or a bit more gives good lubrication to the cam and tappets and reduces the load between them, thus allowing them to bed in. I'm going to make a priming tool that engages the slot in the oil pump gear to make sure I've got pressure before fitting the dizzy.

Glad your engine sounded great!

Cheers,
 
Buick-Aluminum-Engine-19.jpg


You can see the 6 bolt holes in this photo from that web page. I couldn't tell you where I read it though as there is sooo much out there but something about the skylark had 5 and other cars had 6 or whatever the variation was.

I did the oil priming thing, I had a two part bottle jack handle that was just the right length. The photos were just to show others how I did it, I removed the paint before it went in the engine, a rubber one might have been better though. I put the drill on it until oil ran out of the end of the rocker shaft.

I have just broke my you tube cherry and posted the video clip, it is not the best but you get the idea. The carbs haven't been set up so was impressed that it ran.http://www.youtube.com/watch?v=_nxFDrZ4iqo

Colin

116364842b3175c3dccbf8bcbc3a8a1e96781b507be5219d3caf00a82f408db4c75aa2f4.jpg


318396517d9ab7650492f7ce713478334680706b6ee27a35cb0f5841eb47cf0400158e85.jpg


511284854bb25cead781d8f82314dda40a560a57e730ffc1a098add47f98d1c8533a8870.jpg
 
I read somewhere that Rover decided to move the rockers inwards to give more clearance on the inner wings but that then put them right where that inner row of head bolts would have been so they just deleted them and left the outer ones in place.

Colin, thanks for clarifying the tappet preload on your rebuild still needed adjusting as I was worried that the extra thickness of the composite gasket would complicate things with a stock head.

Apologies to long term members who must have gone over this many times.
 
No apologies required from my point of view! I've been following this thread with huge interest. And I've learnt quite a few things from it - not least the oil pump pre running trick and the running in the cam discussion. Both relevant for when I eventually get to fire up my new 4.6! (still apparently as far off as ever, sigh :roll: ).

Chris
 
arthuy said:
...just remember to fill the followers with oil first.
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Hi Colin,

I was just wondering...I know you've already set your preload (sounded good on youtube btw!) but while you were checking it, did the followers compress OK if they were full of oil? I asked the question on the V8 Owners Forum and the advice at the moment seems to be to make sure the followers are emptied of oil. :?
 
Hello Stan,

I'll quote from the Land Rover Engine Overhaul Manual, 1997,...covering all Rover V8 engines from 3.5 to 4.6 litres.

"Immerse tappets in engine oil. Before fitting, pump the inner sleeve of teppet several times using a pushrod to prime tappet. This will reduce tappet noise when engine is first started. Lubricate tappet bores with engine oil and fit tappets"

Ron.
 
Hi Ron,

That's assuming the preload is OK in the first place. If it is, anything you can do to reduce the time it takes to build oil pressure from start up (such as soaking the lifters) is a "good thing". Lifter preload seems to be seems to be skipped over or missed out completely in quite a few manuals, particularly the Haynes Book Of Lies. Reassembly being a reversal of dismantling...etc!

Cheers,
 
Hello Stan,

Yes there is no mention at all in any of the manauls that I have regarding lifter preload. The genuine two part Rover Repair Operation manuals, Haynes and Autobooks along with the Land Rover Engine Overhaul Manuals all make no mention of it.

I assume that provided all OEM parts are used, and nothing has changed from original specifications, then the lifter preoload will fall within the specified limits.

Of course once things are changed, as in your case, skimmed 36cc combustion chamber heads being used with composite gaskests, lifter preolad can no longer be assumed correct.

From my understanding, lifter preolad in excess of 60 thou gives rise to a particularly noisy top end operation, while at the other end of the scale less than 20 thou can produce a high speed misfire when in use, and ultimately premature engine failure.

Ron.
 
Spot on Ron,

20 to 40 thou is where I'll be aiming...and I've got my bits of bent wire at the ready! But resisting going out in the evening to do it...waiting until I've got a good couple of hours at the weekend. I think after 36 years (and my fiddling :) ) it's best to assume nothing is standard and work from there.

Anyway, more anon and piccies at the weekend! Re-mating the new inlet manifold and SU's/linkage at the mo. And a pair of Stromberg CD150s to list on ebay! :)
 
Early finish from work today...(POETS day! :) )...so had a go at the oil pump...

New, taller gears...



Spacer plate...



Cover re-faced (not for the purists maybe! :) )...



And the new timing cover seal to replace the rope one...



Right...time for a bit of scran....soon be time for a pint or three! :D :D :D
 
Be sure to check the spacer plate and gaskets have gaps where you do. A friend blew a few filters off by fitting gaskets that didn't match and I found the spacer I had was missing a hole.

Colin
 
arthuy said:
Be sure to check the spacer plate and gaskets have gaps where you do. A friend blew a few filters off by fitting gaskets that didn't match and I found the spacer I had was missing a hole.

Colin
Click to expand...

Yes...I caught a previous post of yours Colin where you mentioned this. All checked out OK thankfully.

Cheers,
 
just notice you asked about the followers.

I had the followers soaking in oil for weeks til I needed them. did the heads then read about having them empty so what I did was turned the engine over so the oil would have been pushed out. Then did the pre-load. I did the priming after that so hopefully it will be ok

I think there is as many ways to do this as there is people rebuilding engines.

Colin
 
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