4.6 rockers/push rods etc what do i have?

[jad]

Morning!

So i took apart some of my engine and what i can see is not what i was expecting. I was expecting adjustable rockers etc but there appears to be none in either the rocker or push rod. Can anyone tell me what system this is? And how i can identify what make/model of parts?

Thanks

Jad

[neil110]

That is the standard Land Rover Hydraulic system. The valve clearances adjust themselves and depend on good quality, clean oil and frequent oil changes. Frequent as in every 2,500 miles or so. These engines give their oil a hard life

[FridgeFreezer]

Yep, absolutely standard, as used on every Rover V8 ever.

[need4speed]

Yep. Standard. And the best.. Unless your looking to build a sustained high-revving race engine

 

[jad]

Thanks guys. You learn something new everyday! Do older engines have adjustable rockers or am i just thinking of the 200tdi that i used to have?

I am going to be building the engine for my tvr so would like it to rev more.... Anyone know any ways of accomplishing this? I can find much on internet...

 

Thanks

Thanks

[neil110]

With the American origins of this engine it was designed to be low maintenance, hence the lack of valve adjusters to tinker with at a weekend. Thus this engine has never had valve adjustment on it as standard.

When you go to what can be done with the engine it can be turned into something quite powerful. There are many things which can be done to it but, as with everything else in life, there are trade offs to be made in the search for more power. It might be worth your while talking to Turner engineering.

https://turner-engineering.co.uk/html/V8testimonials.html

 

Edited March 20, 2017 by neil110

[need4speed]

Unless you plan to rev regularly past 6-6500 there is no point touching valve gear. Just make sure everything is new and, just as imporatntly, GENUINE.

The valve train wears fast on these engines if not treated to regular quality oil services.

[jad]

Well the rev counter goes to 8000... Would be lovely to use it but i don't think that's going to happen for reasonable cost! I would be interested in getting to 7 to 7.5k at a reasonable cost but that will entirely depend on price. If not 6.5k limit on megasquirt will have to do.

Thanks

[need4speed]

Stop linking an RV8 with high revs. Not gonna happen.

Unless you spend £££££ on a wildcat setup. Which wouldn't make for a nice road engine anyway.

Look over on the V8 forum. There are a few engines over there making ~400hp within 6.5k.

 

Edit: those engines aren't 4.6's, they are 5.2's

[FridgeFreezer]

What he said, the RV8 is not a revvy engine, it does it best work low-down.

Even Nige's lairy JE 5.whatever lump uses std pushrods, rockers and arms.

[Bowie69]

7K with a RV8 will cost you 7K and probably more.

So... forget about it

5500 rpm is a very sensible limit... and lifters starts to pump up over 5800, so no power to be had there

[jad]

Maybe I won the lottery and am happy to spend 7k?  Then again maybe not... 

 

I think my rev limit is currently 5750 but cant be certain. I do hit it occasionally which is the annoying thing! An increase to 6.5 will probably satisfy what I want though.

 

Thanks

[Bowie69]

What do you want 6.5k?

Only reason I can think of is chasing horse power.... By the RV8 is a two valve per cylinder engine, with pretty rubbish inlets that to get any real benefits at 6.5K you probably need to spend 3K on cylinder heads...

Honestly, if you want more than 6K look elsewhere unless you like burning money.

[need4speed]

With double valve springs and genuine lifters you will get away with occasional 6.5 but like asked before, why?

[jad]

Because tvr not land rover. I think I'm talking to the wrong set of people. I always used to get lots of helpful answers on here. It would be nice if people said well you can do this and this but it will cost this and let the person asking make their own mind up. People do things because they want to. No it doesn't always make sense to everyone else but it makes them happy. Maybe I'm just getting cynical now I'm in the over 30 club....

Jad

[Bowie69]

I only asked why! Part of being an engineer is looking at what the end goal is.

I also said you can get to 7k but will cost a lot... And said cylinder heads would be a must really and explained why.

So.... I'm a bit confused why the grumpiness

For what it is worth, the (probably) hotwire system on a TVR has no electronic rev limit, the limit you are probably feeling is the lifters pumping up.

 

[need4speed]

I'm not quite as.........pc as Pete. So with that being said.. Fine. Go to a different v8 biased forum.

They will tell you exactly what you've been told here.

[neil110]

You could go here.

http://www.v8forum.co.uk/forum/index.php?sid=034f39dd2738fa1de462e98c2dd0270b

Or you could pick up the phone 01342 834713  and talk to Frida  at Turner Engineering where you will get the definitive answer within minutes.

I always remember the description somebody gave of a high revving engine. The standard engine would rev to 9,000 but the race engine revved to 10,500. at a cost of about £10 a rev.

 

You should remember that it was originally designed for the American market and having lived there for a couple of years I found that they drive in a very different way to Europeans. I took mine aged 110 with me and when accelerating away from the lights I found I was constantly tripping up over things like Camaros, Chargers, Mustangs and others that were setting off from the lights on tick over, gathering momentum by osmosis rather than acceleration. The speed limits are adhered to with an almost religious fervour, so you see any number of 6, 7 or 8 litre cars trickling along at 55MPH. The majority are not even remotely interested in exploring the performance of their cars, just being able to talk about it is enough and the majority of cars reflect this with lazy engines producing the bulk of the power at lower revs than would be typical for European cars, even those with similar sized engines

Edited March 21, 2017 by neil110

[Bowie69]

Hmm, seems a post of mine disappeared.... 

What I basically said was....

I asked why, because as an engineer part of the process is looking at the end goal.

I then gave you an indication of the likely cost to get to 7K, and also explained that cylinder heads would likely be 3K of that budget if you actually wanted to make it breathe to make it worth while revving it that much.

The point of showing you a RV8 will cost you 7K, is that you can get a crate 5.3 LS3 , all aluminium, 480HP, similar packaging to RV8 for £4800: https://roadcraftuk.co.uk/index.php?route=product/product&path=37&product_id=736

So why would any sane person spend 15K on an engine just to eek out 350HP? And for it then to be right on the ragged edge of reliability, when the LS3 will do it all day.

Now I am going to explain that the (probably) hotwire EFI on your TVR likely has no rev limit at all, and the brick wall you are hitting at 5800 rpm is the lifters pumping up (it really does feel like a rev limit). There's no spark cut if you are running the dizzy still, and the EFI... well it is pretty basic by all accounts. Also bear in mind your rev counter is probably not that accurate and /or lags!

So... I apologise for assuming that you hadn't won the lottery, or maybe I upset you by inferring you weren't a man of means to pay for a 15K engine, but either way there was nothing wrong with my post. 

[Bowie69]

Oh, my post has reappeared somehow! How weird, maybe I am on mod approval

[FridgeFreezer]

Case in point, an easy, reliable, and cheap 500hp in the space occupied by a Rover V8:

[Bowie69]

Oh, and parts availability for LS engines is almost second to none, and likely to be around for just about ever. Whereas RV8s, no matter how much we love them, are pretty old hat now.

[neil110]

Interesting to note that the LS3 is producing peak torque at 4500 rev/min and peak power at 5750 rev/min

[FridgeFreezer]

The LS is producing more torques than the RV8 right across the board. Also they're silky smooth and utterly effortless. Probably because they have 50 years more R&D behind them despite still being a basic pushrod V8.

[Chicken Drumstick]

22 hours ago, jad said:

Well the rev counter goes to 8000... Would be lovely to use it but i don't think that's going to happen for reasonable cost! I would be interested in getting to 7 to 7.5k at a reasonable cost but that will entirely depend on price. If not 6.5k limit on megasquirt will have to do.

Thanks

Hope this doesn't come across sounding rude, but I think you are seriously misunderstanding what the engine is. The high numbers on the tacho mean very little.

Most OHV push rod V8's are not high revving engines. Even the full out race motors. There are many reasons for this, but mostly it's about valve control.

To allow airflow at high rpm means you need large valve openings. But with 2 valves per cylinder this is difficult. As you end up with very large valves and heavy springs. This gives very poor control at low rpm and often very poor low rpm performance.

DOHC and multi valve technology (4 or 5 valves per cylinder) solve this. As it's easier to open more smaller vales a little bit, than one big valve a lot. The upshot is, the powerband is broader on engines that use this technology. So you can have something road usable and high rpm.

Piston stroke vs bore can affect how revvy an engine is too. And there are lots of other technologies such as variable intake lengths, VTEC, VVC, MIVEV that alter the cam profile across the rev range.

The downside is, all this tech usually adds complexity, weight and cost to an engine. And they don't always perform better overall.

 

To give an example of rpm. The Honda Type R K20 engine is known for high rpm activities, 8000rpm or so. The Rover K-Series is also quite a revvy little engine, but more at 7000rpm. But the interesting thing to note is, the Honda engine is very short stroke compared to the Rover engine. So while their PEAK rpm seem very different, I believe the Rover engine actually has the faster piston speed, as the piston has to travel further on each revolution.

 

 

As for the Rover V8 itself. It is still a fairly compact and lightweight engine and is a very good engine for around 250hp.

The big limitation is the heads can only flow so much air. So a 3.5 or a 4.6 (or even a 5.0 litre) can all make rather similar PEAK power numbers. The larger capacity engines will make more low and mid range power however and feel faster and more powerful.

If you want to spend BIG money, it is easily done on a Rover V8. But most times power outputs only end up being moderate to disappointing.

There are many claims of big power Rover V8's. However when any are dyno'd the numbers are always a lot lower than you think. I've seen lots of built 5.0 units or 4.8's, often claiming silly amounts of power. Only for them to put up a dyno figure of around 280-290hp. A well built 3.5 will feel more revvy and make 220-230hp.

 

What TVR and what V8 do you have?

If you want go faster bits for RV8's, try here:

http://www.v8developments.co.uk/products/index.shtml

 

But there is simply loads and loads and loads of info on the internet. It's a hugely popular and common engine in the UK and Europe and has been around since the 1960's.

 

Personally I'd not go too mad. A simple cam, good tune and some bolt ons will probably get you 80-90% of the way. The last 10-20% will cost you huge and probably not make as much difference as you think.

Also consider power adders such as supercharger, turbo's or even nitrous oxide.