Which Way to go?

In the Dax I have a Morgan engine (3.9litre) (Same as Rover / TVR V8 but actually came with Morgan numbers)

It is currently fuelled using the Lucas "Hotwire" system of fuel injection, however as the engine has been modified with bigger valves, porting, balancing, raising CR, pocketing pistons etc the injection system cannot cope too well. Cam specs were discussed here http://www.gt40s.com/forum/gt40-tech-engines-induction-exhaust/20038-rover-engine-cam-specs.html

I am reluctant to change the cam - sort of it it ain't broke don't fix it and the fuelling seems to be "causing " the problem

The motor great when you ask for power or acceleration and at Santapod did almost the same time and speed as other GT40's fitted with Ford 302 motors, but at low throtle and low revs 1500 - 1900rpm in traffic she kicks and bucks as the overlap confuses the ECU and it says "too lean" and then "too rich" and causes a kangaroo effect.

I have got around this in the past by running in a lower gear and having the engine rev higher but this again gety tyring (not to mention hot and noisy)

So time to get things to work better.

Options are (or ones that I have found)
1) Have Megasquirt supplied and fitted and mapped - this will still use the plenum etc of the existing system but be mappable and also run the sparks through coilpacks (£1500)
2) Remove the injection and fit a manifold and Holley - the carb will be less fuel efficient but as I maxed at 3000 miles in a year will not make too much difference in running costs. The Holley would be 390cfm which some say could be too small at WOT (£780)
3) Remove the injection and fit a manifold and Edelbrock / Weber 500 - Which some say is a better carb (£780 fitted or about £500 for the bits)
4) Quad Webbers / Delortos and manifold and tuning (£2500 - £3000 and outside my budget)

Options 2 & 3 retain the current distributor system which appears to work reasonably.
Option 1 and existing are EFi which in my opinion are OK but not really in keeping with a GT40

So what is the better carb to use? Holley would require more setting up time and is potentially too small at WOT, Weber is said to be really easy to set up and tune but is not recomended for racing - around corners fuel can cause lean or rich running.

And yes I have Scottish blood so want to spend as little as possible to get a more "easy to live with" car

What's your thoughts?

Ian

Instead of a Holley, you might try a QuickFuels or ProForm 600 (the smallest they make); all the jets and bleeds are adjustable by replacing them, the accelerator pump cam can also be changed out, etc. This engine was originally made by Buick, I think; there may be and Edelbrock intake manifold available for it.

I have a ProForm on my Cobra. It was easy to tune, although the fellow that did it with me has extensive experience with Holleys. But he thought it was very well worked out. QF and PF carbs use all the same tuning parts as Holleys but they are machined from aluminum billet and don't have the casting defects Holleys have had.

As far as the 4x2 Weber setups, although I am planning those for both the Cobra and GT40, they are not for the faint of heart either in cost or complexity, so I would use one four-barrel; best bang for the buck, or sterling, or Euro, or whatever.

Hi Ian,
It seems as though the cam is a bit too radical for road use. Whatever you do to the inlet and sparks there will still be a lot of low end fluffing due to the overlap. Also whatever you do you will need to cost in the rolling road time to get it running right. I don't know anything about the Lucas ecu but the megasquirt or equivalent will do the biz.
I would suggest you bite the bullet and sort the cam for something more drivable and then whatever you use for fuel and sparks will work better. A carb would not like a lumpy cam at low revs due to the overlap but will be happy with a road cam and would be a cheap set up to buy. There seems to be a good supply of them on Ebay. However you have the injectors and manifold already so a new ecu which is more easily programmed than what you have may be a better idea.
The idea of a hot cam is very tempting with anice whoosh at the top end but in your case the thing is that it is broke and does need fixing as it doesn't run right! A friend with a 302 had a hot cam which caused problems like yours and it used a lot of fuel as it spent most of it's time spitting and gargling. A change of cam made it easy to drive on the road, much quicker, more responsive and used a lot less fuel as well. Unless you drive a track speed most of the time a lumpy cam is a pain in the arse with all the coughing and spluttering at low revs and in traffic. A change of cam will give you a much easier drive and you will pick up a lot of low down torque which you don't get at the moment.
Just my 2c.
Cheers
Mike

Jim and Mike

Many thanks for your comments

Mike, I am reluctant to say but you seem to be correct on this - I bought it is a part built project and the first owner spent a lot of money having the engine worked over and was presumably looking for a "track day" type engine

I'll look into a better specced cam and followers - see if the recession has brought the prices down a bit

Ian

If you want advise on tuning the Rover V8 then the best place to start is in some of the TVR forums. The Rover engine was used allot by TVR, I have one in mine and there are thousands of options available for these engines.

I would recommend these people: http://www.t-v-r-services.co.uk/
They are just off the North Circular, near Staples Corner. I have used them before and found them very good (although that was 5 years ago). Also TVR Power in Coventry ( TVR POWER - PERFORMANCE - SERVICING CENTER - PARTS - UK - HOME ) have a very good reputation.

If you don't mind travelling a bit further afield, TVR Servicing - Raceproved Ltd can do some amazing stuff with these engines.

I would advise, before throwing the cam away, to go and see some of these people as the Lucas injection can be re-mapped or a new ECU can be fitted while retaining all your sensors and injectors. And this should help in calming your cam down. If you still want to replace the cam it was about 700-1000GBP the last time I looked, you can get allot of ECU and rolling road for that kind of money.

As an aside, If anyone knows of any good Holley setup guys in the UK, I would be interested to know. PM me if it violates "advertising" rules.

Having just read your post on the cam specs, I would have to say that a 302 duration cam is probably far to wild for the road, and a new ECU would not calm that down. Even the 5.0 TVRs only had a hybrid 218 duration cam.
To ease the pain on your wallet, its quite a straight forward job to replace the cam in the rover engine. Like most American V8s it hides behind the front timing cover and the inlet manifold will have to come off but its about half a days work.

IanAnderson said:

Cam specs were discussed here http://www.gt40s.com/forum/gt40-tech-engines-induction-exhaust/20038-rover-engine-cam-specs.html

I am reluctant to change the cam - sort of it it ain't broke don't fix it and the fuelling seems to be "causing " the problem
Ian

Click to expand...

Ian, you visited this issue nearly four years ago and the advice was to change the cam, and still you have done nothing. Unfortunately in your case the cam IS broke. It is the root cause of your problems. Do as Jac Mac suggested and change it out for something like an XE262H. One of these worked well in the 3.5 that I had early on in my TR7 along with, variously from time to time, an Edelbrock or Offy manifold (no seat of the pants discernible difference between them). Topped with a 500 cfm Weber/Edelbrock carb. This was a good tractable combo, but your FI may well be OK with the milder cam. So change the cam and see how the FI likes it. If it's still not sweet enough, either get the FI set up to suit, or change it out for the 500 Weber/Edelbrock carb, and Edelbrock or Offy manifold.

The Edelbrock/Weber 500 is easy to setup, I can give you a starting point for jets and needles if you go that route.

Check out these guys and their site in general RPi Engineering - V8 Engine - Carburetion and fuel Injection They are a bit pricey but it's all good info.

This is a list I found of Cams available in the UK at August 2008 - most probably still available

So what would be good and why? I don't understand what the numbers mean

Oselli RV8255 22/62/62/22 264° .421" Hyd . Mild Road Extra low and mid end power. Good for towing/load carrying.
Oselli RV8271 28/64/64/28 272° .439" Hyd . Road Improves mid and top end power. Good flexibility.
Oselli RV8214 31/73/80/34 284/294° .469 "/.494" Hyd. Road Good all round improvement.
Oselli RV8286 44/72/72/44 296° .439" Hyd . Road Excellent road cam. Ideal for fuel injected engines.
Oselli RV8480 36/76/76/36 292° .480" Hyd . Fast Road Extra mid and top end power. Ultimate for auto-transmission.
Oselli RV8502 37/77/77/37 294° .495 " Hyd . Road/Rally Slightly lumpy tickover. Good power 2000 rpm upwards.
Oselli RV8224 36/78/85/39 294/304° .494"/.520" Hyd. Road/Rally Extended top end power with up to 7000rpm
Oselli RV84 35/71/71/35 286° .516" Hyd. Rally Good all round competition cam. Power band 2500-7000 rpm
Oselli RV8481 42/82/82/42 304° .496 " Hyd. Rally Poor low end tractability. Power band 3000-7000 rpm
Oselli RV8234 38/80/87/41 298/308° .520"/.542" Hyd. Rally Poor idle and low end but excellent power over 3500 rpm
Oselli RV8500 46/82/82/46 308° .542" Hyd . Race Ultimate hyd. camshaft. Power band4000-7000 rpm
Oselli RV8900 42/78/78/42 300° .500" Solid Rally Poor tickover. Excellent mid and top range power.
Oselli RV8100 47/83/83/47 310° .530" Solid Race Maximum power for full race spec, engine.High rpm.
Kent H180 28/64/64/28 272° .439" Hyd. Mild Road Good for automaticsPower band 1000-4500 rpm
Kent H200 20/64/69/25 264° .435 "/.460" Hyd Mild Road For pre-SD1. Also good for automatics.
Kent H214 31/73/80/34 284° .469 "/.494" Hyd. Fast Road Very flexible. Power from 1500-5000 rpm.Good road camshaft.
Kent H224 36/78/85/39 294° .494"/.520" Hyd. Road Rally Slight loss of flexibility. Power comes in 2000-5500 rpm.
Kent H234 38/80/87/41 298° .520" /.542" Hyd. Rally Poor low end, but improves mid and top end power.
Kent GPA 44/76/76/44 300° .390" Hyd. Rally Same valve lift as standard engine (.390")
Kent M238 42/78/78/42 300° .512" Solid Rally Higher rpm use. Power band from 2750-7000rpm.
Kent M248 48/82/84/46 310° .533" Solid Rally/Race High rpm camshaft. Power band from 3500-8250rpm
Kent M256 42/70/83/39 310° .546"/.564" Solid Race Ultimate race cam. Full race engine only. Power 4000-8250 rpm
Piper HR270 22/62/64/28 264°/272° .421"/.439" Hyd. Road Flexible with good mid and top end improvement.
Piper HR270/2 28/64/64/28 272° .440" Hyd . Fast Road Mk1 1 of above cam.
Piper HR285 44/72/72/44 296° .439" Hyd. Fast Road Ultimate road cam. Tractable but slightly lumpy tickover.
Piper HR300 36/68/68/36 284° .440" Solid Competition Accent on mid-range power. Power band 3000-7000 rpm.
Piper HR320 52/84/84/52 316° .471" Solid Race Mid and top end power. Excellent circuit race cam.
Crane H-194 10/54/59/15 244/254° .400 "/.430" Hyd. Road Economy cam only. Not to be used with comp. ratio over 8.75:1
Crane H-204 15/59/65/21 254/266° .430"/.456" Hyd. Mild Road Improvement over standard cam. Can be straight swap.
Crane H-216 21/65/71/27 266/278° .456 "/.480" Hyd. Road Excellent all rounder. Good power increase across rev. range.
Crane H-224 36/78/85/39 294/304° .494"/.520" Hyd. Fast Road Slightly lumpy idle. Good for lighter vehicles eg. sports cars.
Crane H-234 38/80/877/41 298/308° .520"/.542" Hyd. Road/Comp. Ultimate hyd. cam but compromise in road car.
Crane F-228 38/72/74/36 290° .491 " Solid Road Particularly suitable for turbo or supercharging.
Crane F-238 42/78/78/42 300° .512" Solid Road/Comp. Wide power band. Does not need high rpm.
Crane F-248 48/82/84/46 310° .533" Solid Rally Wide power band. Works well with Holley 4-barrel carb.
Crane F-256 42/70/83/39 292/302° .546"/.564 " Solid Competition Good mid and top end power.
Crane F-266 47/75/88/44 302/312° .564"/.584" Solid Competition Out and out power. Engine must be capable of high rpm.
Crane F-276 52/80/93/49 312/322° ,584"/.602" Solid Competition Radical race engines only. The ultimate.
JE Motors JE101 20/65/25/20 265/225° .430" Hyd. Road
JE Motors JE102 43/79/79/43 302° .500" Hyd. Fast Road Good power from 3000-6500 rpm. Peak torque 5000 rpm
Holbay 111R 39/73/73/39 292° .429" Hyd. Fast Road The Tornado
Holbay 125LHC 40/84/89/45 304/314° .520"/.541" Hyd. Competition Designed for maximum performance within rpm limits of hyd. lifters.
Holbay K3A 58/88/74/50 326/304° .432" Solid Competition High torque design.
Holbay 751R 63/95/95/63 338° .451 " Solid Competition Maximum bhp at higher rpm.
Holbay Standard 30/75/68/37 285° .390"/.385" Hyd. Production 3. 5-litre (SD1)
Rover Standard 32/73/70/35 285° .390" Hyd. Production 3.9-litre (designation ETC 8686)
Rover Standard 28/77/66/39 285° .390" Hyd. Production 4.0-litre (designation ERR 3720)
Rover Standard 14/70/64/20 264° .416" Hyd. Production 4.6-litre (designation ERR 5250)


Lots to chose from - so which direction for a tractable road cam that will still give reasonable power?

Ian

Hi Ian.

This is just a basic explanation of how cams work, there are guys on this site who know much more than me, and have had lots of experiance with the Rover engine. so take their advice on cam choice

The numbers relate to when the inlet valve opens....30
when the inlet valve closes...60

when the exhaust valve opens...60
when the exhaust valves closes...30

The .430number etc is how high the valves lift. The higher the number, the higher the valves lifts hence the expression "High Lift Cam"

In genral high lift cams will give more power, but it will create more strain on your valve train, and also you may get clearance problems with your pistons , at TDC

There is a point when the inlet valve opens before the exhaust valve closes. This is known as the overlap peroid.. 30 + 30 = 60 degrees overlap. The greater the overlap period. the more top end power you will have, but this is what causes your engine to run lumpy, at lower revs, and make your car difficult to drive in traffic. But if you have large carbs and your inlet tracks opened up, that will also not give you very good power at low revs, because you cannot get enough air speed at low revs to get the mixture in the combustion chamber
Large carbs, large inlet tracts, and a big overlap will give you top end power, but you will sacrafice your bottom end

When the exhaust valve opens, is also very important in getting good power. The sooner it opens, the more the engine will rev, the later it opens, the more bottom end power you will get
The opening of the exhaust valve also has a lot to do with your exhaust system. when the exhaust valve opens a positive pressure wave is created, and in concuntion with the lenght of your primary, and secondary pipes, will also change your power characteristics

When tuning an engine..".You dont get anything for nothing " In other words if you go for top end power you will loose out at the botom, and vise_ versa A good even spread of power, is what you need to aim for.

A bigger engine is the best way to go for more power.

I hope this helps, if you want to know more just ask

Ive tried to put it in a simple form, but there may be some people that disagree with me,

mick

Probably pub talk but someone has suggested some Rhodes Lifters

They are said to bleed down below 3000rpm giving the cam a much less agressive profile and then "pumping" up at higher revs.

Drawback is they clatter at low revs but over the exhaust note that would probably not be heard


Are they any good or better to change the cam?

Ian

Ian,
As I said , Im not an expert on Rover engines. but thats what Im useing in my car.....

The lifters may help, (I really dont know....) but it wouldnt take much longer to change the cam at the same time....

"Prevention is better than cure" and your problems are caused by your valve timeing, so changing your cam is the best way to go

mick

Ian,
Firstly sit down and think about what you want the car to do. Secondly, think about where your going to drive it and where the engine spends most of its time RPM wise. Only when you have got a clear idea of what you want the car to do and how you drive the car, are you then able to choose a cam shaft.

My advice would be, for a road car, a 270 to 280 degree duration cam. Any more and you get into lumpy tick-over and problems with tractability.

The numbers relate to the timing events of the cam. For example, this cam:

Kent H214 31/73/80/34 284° .469 "/.494" Hyd. Fast Road Very flexible. Power from 1500-5000 rpm.Good road camshaft.

The inlet valve opens at 31 degrees before TDC and closes 73 degrees after BDC. The second two numbers relate to the exhaust valve, it opens 80 degrees before BDC and closes 34 degrees after TDC. The number 284 relates to the duration of the cam, or for how many degrees of crank rotation the valves are off their seats for, in this case 284 degrees. The last two numbers relate to the valve lift of the cam.

Unfortunately there is no absolute convention of how cam timing events are presented, but this is how I have found it to be usually done.

Hope this helps.

I would also suggest the Rhoads lifter. You may want to try their new V-Max (latest generation) that allows you to adjust the bleed down rate to your cam profile.

Cheers, Jacob