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Joined: Jan 15 2016
Posts: 412

So, this morning, I got my new work schedule and as of next year, I'm demobilised for two months a year, starting February.

Step one is probably a holiday (not had for three years) but my mind also turns to the V8, as it would.

Mileage is fairly low, 115,000ms, if memory serves, but with no history to go at and given the state of the first couple of oil changes, I have no idea how long it had been running with basically black water in it.

Now, don't get me wrong, the engine runs beautifully, idles evenly, revs happily, so I think the fundamentals are okay. I just feel there's something a bit lacking and, given the above, maybe the cam is due replacement. I'll also have time on my hands to do it.

Sooo, What to do? Whilst I'm in there, it would be a shame to just replace stock for stock, without going wild. Seems to me there's the choice between Piper and Kent and several suppliers offer kits-ish.

However, the kits don't seem to offer pushrods or cam bearings. Why wouldn't I change them whilst stuff is in bits? How easy are cam bearings with the engine in situ?

Any recommendations on cam and any, "do's and don'ts", any cam specific tools I'll need?

This is, obviously in the future but, having to get everything together can take time, so I'd just like to be ready to roll.

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Joined: Dec 30 2015
Posts: 4560

Can't give you a cam recommendation but cam bearings are supplied undersized, fitted and the block then line bored so not something that you can do with the engine in situ.

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Joined: Dec 30 2015
Posts: 1173

I went with a Piper Torquemax cam in my engine build. Definitely has a bit more pep off the line.

I wouldn't worry too much about the cam bearings, but the cam itself could be a reason it's feeling a little lethargic.

I did the pushrods in mine as I was building a complete new engine - but again, unless one is damaged, then you're probably OK to reuse - you will need new tappets obviously to run in with the new camshaft - but most of the cam 'kits' come with tappets aswell.

I believe I paid about £450 for the torquemax cam kit - which included tappets, timing chain and sprockets, and all the gaskets etc required. This was about 10 years ago that I bought the kit though... and it only got installed 3 odd years ago - but it's still running nicely it seems.

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Joined: Aug 07 2019
Posts: 138

it depends on how far you want to go , cam, lifters or tappets as some may say ? timing chain and sprocket , maybe the oil pump, its there , also check the top end rocker gear for wear usually the under sides of the shafts wears. check the cam bearings but doubt if they will need replacing
PS i thought they were just a press fit babbitt bearing not line bored, who would have guessed.

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Joined: Jan 15 2016
Posts: 412

Thanks all. Some food for thought.

I'd go with a kit, although they're a bit dearer now than when Marty got his, and several of them come with timing gear as well, so why not!

Hadn't realised about the cam bearings either, so they'll get left well alone, thanks Richard.

Mad-as, cheers for the heads up on the checks.

This is as much to do with filling in the new time off work I'll be getting as of next year, so if we can pep the old girl up with a slightly tastier cam whilst heading off wear issues, then it seems like a plan.

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Joined: Feb 25 2020
Posts: 142

Slightly offtopic but always cam-related -> how does the Piper Torquemax fare against the Kent H180 Sports Torque cam?

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Joined: Aug 07 2019
Posts: 138

just a little FYI for those thinking that a race cam or some other cam will be better than than one you have as standard, just remember that the ecu is not tuned to run a different cam and mapping is done with the replacement off the chips in these not a laptop (gems not sure about the bosch) . also that your heads may need some work to make the benefits of the cam work properly , then it's the exhaust and manifolds that may require replacing as well , there isn't much point putting in more fuel and air if you can't get it out .
when building a race motor it starts with the crank grinding , different surfaces for different purposes. just that in itself should say something, you can't just replace parts and expect them to work properly if you don't do the other bits to go with it . in most cases when people replace their cam only, do not admit that its not running right , it has a dead spot or it runs rough in a certain area of the rev range or uses more fuel for no real gain.
do your homework before going down that rabbit hole, think conservative .

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Joined: Jun 17 2018
Posts: 543

The Kent H180 cam is one i'm considering..

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Joined: Dec 30 2015
Posts: 1173

The Piper Torqumax and the Kent H180 are (i believe) pretty similar. the Torquemax is designed as a 'fast road' cam, which isn't very extreme and works fine on the standard engine tuning.

The biggest thing I've noticed is that the torque curve is brought down a bit lower. there is more pull off the line, and more response from the engine from about 2000 rpm up to 3500 rpm, whereas on standard profile cam, the max torque isn't produced until about 3400? rpm...

Most of my driving is fairly light footed, and the engine runs most of the time between the 1800 - 3000rpm range, and it feels a bit livlier with the Torquemax in comparison to the old standard cam. I recently measured the lobes of the old cam and it wasn't actually that worn.

If I were going with anything more 'performance' based, then as mas-as says - the real gains of it won't be seen without the engine being mapped and probably some porting/gas flowing of heads and the likes..

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Joined: Dec 30 2015
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Maximum torque, on a GEMS anyway, is around 2500-3000 (https://www.automobile-catalog.com/curve/1997/1398590/range_rover_4_6_hse.html) which is why you get better economy at 70-80 mph than at lower speeds as the engine is running at it's most efficient. There's naff all below 2,000 rpm though.

Tuning a P38 is different to tuning the same engine in something like a Morgan. We don't need more power at the top end and a high revving engine, we need the grunt low down.