Anyone Know What a 102 Cam is?

[Ian Anderson]

I was swapping my 14CUX ECU today for one from E Bay

On the back on my ECU is a sticker that says
3.9 Single Plenum
102 CAM
Dated 20=06=90 and signed JE

The motor was prepared by JE Motors (Later to become JE Engineering)

So is the cam a radical grind?

Still having Fueling peoblems

Thanks
Ian

[racer]

On the back on my ECU is a sticker that says
3.9 Single Plenum
102 CAM
Dated 20=06=90 and signed JE
So is the cam a radical grind?
Still having Fueling peoblems
Thanks Ian

Not off the wall but at the very high end of fast road cams. .5" lift and close to competition timing with overlap. NOT a daily driver.

It will give its best performance between 3000-6500 rpm with the most torque at about 5200 rpm. Under that, you will have fueling problems with anemic response.

It is a cam for me..not you.

racer (who has learned to avoid "performance cams" with these engines unless he is oval track racing)

[Boosted LS1]

I had one years ago in a 4.5, it's


43/79/79/43 302 degrees .500" lift


Boosted.

[Ian Anderson]

OK that seems to start making sense now.

At 3000 rom in 5th (80mph) hit the accelerator and the seat slams into my back.

Try to get it to go along in 3rd at 30mph 1700 rpm and it will not cruise in a line of traffic and bucks like a bronco on kangaroo petrol.

So can this be tamed with EFI system tuning or is it asking too much?

Would a webber carb system make it more usable for road?

Or is it time to get a amer cam?

Cheers
Ian

[Boosted LS1]

Management may help but it won't mask the cam's characteristics. What about a keyed sprocked so you can advance/retard timing 4 degrees?

Boosted.

[Ian Anderson]

Tell me more

How and where is the sprocket fitted? And will it make the thing drivable?

Or do I just have to run it in frst gear and 4000 rpm to travel in traffic?

Or failing that what is involved in a cam change? I would think Engine out, heads off, sump off, bottom apart and then rebuild or is there an easier way?

Engine now has 200 miles approx on it (200 miles and not 200 000 miles)

Ian

[Boosted LS1]

If you can get the timing cover off you can change the cam sprocket for a Real Steal item with 3 keyways. It allows you to advance or retard by 4 degrees which may help. You may want to advance the timing. You could even just move the chain a tooth or two if you worked out the effect it would have but before cranking the engine over I'd rotate it by hand.

Do you know what pistons you have or if they have deep valve cut outs?

Boosted.

[Ian Anderson]

Nope

Just have the bill where the bloke that started the project paid JE £3247.60 in 1990 to balance and build the engine.

Work sheet says
Strip unit (brand new engine)
M/c piston cut outs for JE102 and balance
Balance Conrods
Balance crank and front pulley
Lighten and balance flywheel
Balance Clutch cover
Fit 102 + Hi rev lifters
Fit JE Duble valve springs
Curved Seats and Large Exhaust Valves
Open exhaust ports to "our" size
Fit large trumpets andmatch to inlet manifold
Latest shape combustion chambers
Modify ECU and tune resistor
Byno with "Tommy Cooper" installed
Oii feed kit and tadpole

When I got it the heads were marked in pentel pen "TVR spec"

So is this a "race on;ly" set up?

Ian

[Boosted LS1]

Ian, it's what I'd call a decent fast road engine. Just like on a tvr, in fact probably a bit better then on a tvr because you'll have decent pistons. A lkot of tvr's had a bog stock landrover bottom end.

Nice they machined deeper cutouts in your pistons which are no doubt Omega's. Could even be forged but usually they used cast Omega pistons. It's also nice you got the ported intake manifold and larger trumpets. Engine spec sounds quite nice

Boosted.

[racer]

Nope

Just have the bill where the bloke that started the project paid JE £3247.60 in 1990 to balance and build the engine.

They certainly aren't cheap!

M/c piston cut outs for JE102 and balance
etc etc

So is this a "race only" set up?
Ian

No, not completely. It can be road run. It is an ideal setup for an extremely light vehicle, run with a very heavy foot on flat country roads. The road driver who choses it would be more interested in high bhp and high speeds than low down torque, instant response and acceleration.

The issue is what YOU want from YOUR vehicle. tell us that and the fix (if any) becomes easy to offer.

racer

[Ian Anderson]

Racer

The GT40 is 1150kg with full tanks at SVA so good an light. 5th gear 6000 rpm is 160mph - I'd like to see how close I can get! (OK needs work on suspension etc. to get it accurate enough for that)

I will use it mainly on the road but would also like to do track days and a couple of RWYB strip days in a year. The road use is for shows Kit car gatherings etc - not that it a Show Queen and I would rather use it than polish it! So much so that I don't even have aircon! (But the heat should certainly help me lose weight)

Track days are also getting to be tight as it runs at 105db at 4000rpm static rev test at SVA before it was strangled to get through the test.

The 30 / 40 MPH stuff is on local roads and a real PITA

So make a suggestion

thanks
Ian

[racer]

Racer

The GT40 is 1150kg with full tanks

Good! Big help. Lighter is considerably cheaper than more powerful and the bottom line is better.

5th gear 6000 rpm is 160mph - I'd like to see how
close I can get!

Sounds like a LT77 or a R380. Am I correct? Then it will make it to 160mph if you can it to cruise at 5800 rpm in 5th. Even so, there will have to be deep compromises.

I will use it mainly on the road but would also like to do track days and a couple of RWYB strip days in a year. The road use is for shows Kit car gatherings etc - not that it a Show Queen and I would rather use it than polish it! So much so that I don't even have aircon! (But the heat should certainly help me lose weight)

Nothing wrong in using your car to meet people. That is one of the reasons we have them. As for Garage Queens...Concours is simply another type of automobile competition with just a bit more politics to it than racing.

Track days are also getting to be tight as it runs at 105db at 4000rpm static rev test at SVA before it was strangled to get through the test. The 30 / 40 MPH stuff is on local roads and a real PITA

No surprise. That spec can't do better than that out of its element (which is fast rallying/racing. Not flexible enough for thel road. [/quote]

So make a suggestion Ian

Just a bit more info, Ian. Do you have your rear axle ratio and can you confirm the gearbox type? Is your engine's capacity stock 3.9? If not...need the bore and stroke.

Most importantly, tell us

1. what driving do you do the most off..(speed, urban, rural, road type)?

2. what are your favorite roads....and what are you revving when you do them?

racer

[Ian Anderson]

The gearbox is a Renault UN1transaxle from a Renault 21 turbo but with a 4 spider diff and uprated input shaft to stop it breaking. It has a 0.82 5th gear and 3.44 Diff See here
http://www.lamboreplica.co.uk/gearbox.html

Regarding the roads never had it further than 15 miles from home so a mixture of motorway and a roads - love the acceleration around the corners on the A Roads and also the effortless cruise at 80mph (3000rpm on the motorway) The car is a pig in the wet as it seems to be like a 2 stroke and suddenly hits a power band and spins the wheels)

Reason for the low miles (200 since July) was the running lean found at SVA and then a major gearbox oil leak - leak now cured and supposedly now should be OK on the mixture.

The hillclimb idea really interests me

cheers
ian

[racer]

The gearbox is a Renault UN1transaxle from a Renault 21 turbo but with a 4 spider diff and uprated input shaft to stop it breaking. It has a 0.82 5th gear and 3.44 Diff See here
http://www.lamboreplica.co.uk/gearbox.html

You will have a hard time reaching 160mph with those ratios..and (I assume) 15 inch wheels. On the other hand, if you sort your car and its cam a bit, you will have a BLAST at anything under 125 mph and be awesome from 0-100. Porsche 911 performance.

What you have now is a car geared very low with great low end potential yet with a cam that comes on at 3000+. the cam and gearing are making each other look bad. You either change the axle to something around 3.00:1 or find that a cam that compliments the ratios you have.

I am in no way looking for a "sensible fit". After all, these cars are for fun not logic.

Regarding the roads never had it further than 15 miles from home so a mixture of motorway and a roads - love the acceleration around the corners on the A Roads and also the effortless cruise at 80mph (3000rpm on the motorway) The car is a pig in the wet as it seems to be like a 2 stroke and suddenly hits a power band and spins the wheels)

You need a limited slip axle or the back end will be very hard to control. Is the Fiat a LSD?

The hill climb idea really interests me cheers
ian

I like head to head racing the mostly but hill climbs are a LOT more fun than a track day...and normally cheaper.

You have the makings of a winner..just have to push the power band down lower so it comes on almost instantly. As a side benefit, your engine problems should disappear and you will run cooler. It also is significant cheaper than remapping a non-stock car. It will cost you the price of the cam, a timing cover gasket and 3-4 hours.

Before I go on, I must reiterate that, after much sad experience, that I am no great fan of camshaft juggling in V8s. The V8 does not respond to camshaft tuning as well as 4 cylinder engines..and the tendency is to go wilder until you see a big difference. By then you have a very limited use vehicle.

It may sound bizarre, but with your setup, if you want silky smooth running with an immensely lusty mid-range, you will never get more for your money than a 1985 Vitesse EFI V8 cam. Rover was playing around with stock car racing back then and the cam they designed with those hopes was excellent. Probably pick one up at a breakup yard for 10GBP.

After that, I would look at a Piper H270/2 (fast road cam that comes on at 1500) or the Piper H285 (a little faster).

If you don't mind a little lumpiness in your idle, look at the Oselli RV8502, or the Kent H224. I have heard good things about the Crane H244 (Mark Adams favorite) but never tried it and don't have much detail on it beyond it being close to your spec.

All of these cams come on from 1500-2000. With your final ratio..it means they can jolt you back in your seat with a bit of pedal pressure and you can take a hill or a curve with muscle at any speed. Got anti-tramp and panhards?

racer

[Ian Anderson]

No No anti tramp and no panhard - pretty similar to original Ford GT40 that did OK winning Le Mans 4 times in the 1960's fully adjustible on rose jounts for caster camber toe etc. (No anti roll bars yet but they will come)


My build site is here
http://www.gt40s.com/forum/builders-for ... ld-up.html

Gearing should be good for 160 as the tyres are historic style with large side walls on 15 inch rims (26 inch rolling diameter rings a bell) I'll check this evening on the actual size but believe it to be 265 / 60 * 15 from BF Goodrich (Avons now available a bit wider)

Thanks for the CAM info I'll look into that and see what I can locate

Thanks again for all your input when we meet sometime the drinks are on me!

thanks
Ian