The V8 Owners Forum -

what about removing that piston and turning into a V7

sell me your forged pistons
i have my spare 3.9 bottom end here its stripped, also has a set of ARP main studs fitted to the block,,

mgbv8 wrote:Ian has now got me thinking about running the engine dry for 1/4 mile sprints?

I've seen several Rover V8's in various cars doing this?
Another thought to throw in the pot for the future maybe?

Perry

Pel, the other advantage of running a dry block-------You can buy up all the old slipped liner engines you want, fill them with filler then sell off all the bits and bobs from the engine, and sponser yourself for the year,

Would it be as important to have a 4 bolt mains if the block was filled solid? It must stiffen it right up and leave no room for movement in the main caps- if that is the case you could use the cheap 3.9's with ARP bottom ends??

Tom,

Hard block only stabilises the cylinder walls, It does nothing for the mains.

Perry,

If you are running track only and never seeing the road then running dry is the way to go. Maybe just run water in the heads but quarter mile at a time I wouldn't carry the weight of the cooling system. That alone will get you close to that 9 sec pass.

Alan

Water in the heads only Al??

How do I do that????

Perry

I thought it would have stiffened the whole thing- as there must be a tiny amount of twisting down the whole block- but it was only an afterthought!

Well folks!!
The results are in???

I ran 4 nitrous passes last Sunday and JB weld held up just fine ???

you running water in the block still?

Yep!
No leaks to be seen as yet???

Dyno test next Saturday for some more data on AFR and then I can get back up to the shot of gas I was using last year so I can start adding some more

I'm keen to see if the figures are better with this new nitrous plate.

Hi Perry
well done on getting this sorted, great job
To run water in the heads only you need to use a head gasket with all of the water passage cut-outs left blanked, usually people make them out of a copper sheet, just remember to leave the oil passages connecting to the heads. you would be best to use an electric pump to feed radiator water into the heads at the front, you then use the rear water ports on the heads to take the water out of the heads and back to the radiator. (if it is easier you can feed the water in at the back and out at the front.
Best regards
Mike

Thanks Mike!
Thatrs a good bit of info for the next possible engine

Well!
She held up with 4 mental dyno passes??

I didnt get to hit a full power run as I was having aggro setting up nitrous/fuel ratios. But on the best run which was aborted about 6 seconds into full power due to running hellishly rich she still made about 380hp with 450 ft/lbs on 50hp less nitrous than I ran last year.

So although the hp was down by 15 and the torque was down by 50 I'm still happy that the JB weld repair to the block held up

I'm sure the big carb is losing signal from the inlet manifold now when the nitrous expands and knocks out my suction. I wont go into the details but I reckon thats why it goes from very rich afr to very lean afr at full nitrous input when I add another 25hp of gas.

250hp of petrol with 200hp of gas = well rich.
250hp of petrol with 225hp of gas = well lean.

Anyway!!!

To end this thread for the time being I will say that I'm happy that the repair has not only held up for nearly 2 hours of nasp running and tuning. But it has also held up for 4 nitrous passes on the strip and 4 dyno pulls with another 2 hours of nasp running in between



I have no idea what condition the repair under the head gasket looks like right now. And I have no intention of pulling the heads to find out. I'll keep the engine as it is now until I break it

North Weald will be the next test day on May 9th. If she holds up and I get my fuel to gas ratio sorted I'll be at the Retro Show gunning for a sub 10.6 pass

good luck mate,
if she fails,
how long to put the pistons in my block and load it up with gas to see how quick i can go at retro