The V8 Owners Forum -

Ian Anderson wrote:
I suppose it could also explain my "cutting out on overrun" problem as the lean fuelling would help cause the engine to die

Ian

Modern engines are supposed to cut out on overrun for emissions reasons. The flapper EFi has a specific device for doing that, called the Vacuum Overrun Switch. I always disconnect mine as they tend not to cut in soon enough and make it stall.

Chris.

Hi Folks.

Glad you had a good day. Sorry I wasn't there. The B was only delivered to Southampton on friday. I hope to pick her up tomorrow.

I have a set of results that Dave might be interested in as there are for his bottom end. They were taken just before I shipped her to the states, so the engine had only done about 500 miles then. She now has over 4000.

1998 - May
Car: MGB 3.5
Corrected Engine Power: 161.0 BHP
Engine Power: 161.5 BHP
Wheel Power: 122.4 BHP
Drag Power: 39.1 BHP
Max power @ RPM: 5180 RPM
Torque: 253.8 LBF,FT
Max torque @ RPM: 2600 RPM
Max attained RPM: 5285

Regards

Dave

Hey Dave!!!

Good to have you back on here. When you didnt turn up, I said to a couple of the lads that your V8 was probably still in a container somewhere

I kept up with your internet diary. That was some adventure mate!

Dont forget those dyno figures were with the engine running off peak due to the timing issue??

I'm taking a Costello V8 MGB to Martin this week for a rolling road run to get some info before I hoik the engine out and drop in one that I am just building.
I'll also get mine back on soon, as I did some testing at the track yesterday and discovered that I had made a big cock up on my timing too. On the Dyno day, mine was running at only 4 degrees BTDC off gas, and at 1 degree BTDC on gas.
Not sure how much difference it will make to the output, but running 6 degrees retarded would have reduced cylinder pressure somewhat.

See you soon Dave.

Perry

Any one got any photo's from our day?
i did but my camera wiped the datacard and i lost every pic i had taken

Here's a few to be getting on with, Perry has got a lot he can post as well...














Sorry I didn't get any more, it was a busy day!

Here we go at last.

Vid of most people cars of the day (sorry i missed the sd1!)

Its kinda just thrown together but you get the general idea.

May have to turn the volume down for the first bit, Perry's car is somehwat louder than the rest



STUBALL

oh i did have sound until perrys car blew up the speakers

Perry,

Any chance you could post the full graph from your N/A run, I would love to see the full power curves.

I'm particularly interested as where the torque starts to come in as my car is more for road use than yours!

Capacity wise my new engine is 200cc short of yours at 4355cc.cam wise i think the specs are fairly similar and I'm using Buick 300 alloy heads with big valves, 3 angle valve job. bulleted guides and the throats blended to seat size but have purposely left the port runners as cast to promote retention of fuel in suspension at low RPM..The rods are small block chevy and the pistons are chevy 305 Hypereutectic.

The induction system is for the time being Edelbrock 500 and performer manifold with a MGRV8 exhast system.

Have at last got a date to get it fitted, 2nd week of this month and once bedded in I will get it on a rolling road to fine tune it and find out what it's producing.

Kevin.

Sory for the delay chaps. I've been off the scale with work shite.
I'll get the article done in the next couple of weeks or so.

Kev
I'll see if I can find my NASP dyno plot now.

Perry

I think this is the one you are looking for Kev...

Gah!
I was hoping we caught the turbo headers glowing red on the video!

Perry,

Thanks thats very useful. What cam are you using by the way and am I right that you are using near standard heads, if so a little work behind the valves would be beneficial above 3000 RPM and possibly a set of big valves 1.63" and 1.4" would allow it to breath a bit deeper without going to a lot of expence.

Kevin.

Kev
Its all stock 4.6 but with a Typhoon cam from RS and Rhoades lifters. The heads are un-tweaked 4.6 units as well.

Perry

Sorry
I lied. The heads have not been altered flow wise, but I do use double valve springs which have been shiimed to the right fitted height for the cam.

Perry,

The retarded timing couldn't have been helping the torque at the bottom end and the peak BHP figure which is obviously low, but I would have thought that the restrictive heads were causing the early torque peak and the rapid falling off after 2800RPM.

Kevin.