Anyone converted from V12 to V8?

[Mark Cooper]

Has anyone ever pulled a V12 jag out of their DAX and dumped a V8 in her? I ask because on the way home in my cobra, my oil pressure guage was reading really low. I thought it was the sender, because I had my engine reconditioned when I built the car and its only done about 10,000 miles since! But when I replaced the sender, I was horrified to find that it made no differance and for the first time the pressure warning light came on during tickover. It has never done that before.

It might only be the oil pump (only!) If it is, I should be able to get to it without taking the engine out. The DAX doesn't have a crossmember to get in the way... so fingers crossed, but should the reason be more serious, I was thinking of outing the jag for a stonking big V8.

Do you know if this will entail cutting/welding the chassis engine mounts, or is it a bolt on job? Also, what about Gearboxes. I have the getrag 5spd mounted to the jag (the one with the carlton spline for the prop) and it uses the jag flywheel and clutch. Can I get a bell housing to fit the engine and box, or will I need a new box as well.

Any stories about converting your DAX to V8 would be very interesting. My car is the supertube V12 tojiero.

Regards
___________________________
Mark E. Cooper
Impulse Books UK
08707517412 (Fax)
http://www.impulsebooks.co.uk
___________________________

[ian]

Mark, I converted my Dax from V12 to V8. Mine is the ladder chassis.
Lots to think about, keep the Getrag box because you can use that. You will need to have the engine mounts changed. It would be worth talking to Dax about this, they did mine for me. If you want to talk about it more please give me a call on 0118-946-3263. Ian.

[Steve]

Ak will sell a kit for converting the getrag box to fit a chevy or ford, the bellhousing & clutch will be from your chosen engine,


the engine mounts will need to be cut from the chassis & replaced, but dax will do this for a small fee, on the box chassis, there is some releiving done for the starter motor on chevies, don't know if thats required for a supertube.

the expensive it outside of the engine is the exhaust, the rest is relatively straightforward

PS glad the steering worked out OK

[Mark Cooper]

Thanks guys,

The steering is great, Steve. Thanks for all your help with it. I wish I had done it years ago. I'm going to change the steering wheel to a smaller one now.

My problem with the engine was a shock to me. Before the little accident that caused me to put power steering into the car, the engine was fine. Now I have very low oil pressure. It might be something really simple--there is adent in the sump. Maybe the oil pump was damaged in some way--it seems unlikely, the sump isn't punctured or really seriously dented, but it's something to look into. If it is a simple matter to fix, I will leave the V12 in her... I would much rather buy a V8 cobra than convert my car into one, but if the oil pressure is evidence of something more serious, I might well go ahead with the V8.

In the past, I have always considered using a chevy v8 rather than the Rover that some use. My eyes have always been bigger than my wallet I would want something BIG I'm glad the Getrag gearbox is usable--should save a bit on costs. Did you source your V8 engine through DAX, or did you have some other contacts? How much does a good chevy V8 cost these days? I'm a little out of touch now... my car has been finsished over 10 years.


Regards
___________________________
Mark E. Cooper
Impulse Books UK
08707517412 (Fax)
http://www.impulsebooks.co.uk
___________________________

[Steve]

Dent in the sump?, I'd check a manual to check the location & see if the oil pick up screen could be blocked by the dent, or if there is a possibility the pick up arm was loosened, busted at the time, causing an air leak.

If it was fine before the bump, then its likely to be a cause.

re a chevy, you could rebuild one for perhaps 1500, use real steel for 2-4k for new one, or have someone build one, just need to decide how much HP, and how much cash you want to spend

[kdavies3]

I would agree with what Steve said.
Remove the sump and check the oil pick up. It may have been damaged during your bump. It only needs a small crack or loose joint to suck air instead of oil.
If it's sucking in air it will be airating the oil and won't be doing the bearings much good.

http://animatedgif.net/flags/-flags-uncat/Wales.gif

Kev Davies
Dax, 383ci Chevy Stroker, Tremec TKO
South Wales

[Mark Cooper]

The dent isn't really big. I doubt it os blocking the pickup screen, but it might have moved the pickup pipe so that its sucking air. I certainly won't leave it like that. I'll have to check it out and when I do I'll check the pump at the same time.

Thanks for the advice. I'll only do a V8 if I think the V12 had had it. I would like a V8 anyway, but the V12 cost so much that I hate to throw it away.

Regards
___________________________
Mark E. Cooper
Impulse Books UK
08707517412 (Fax)
http://www.impulsebooks.co.uk
___________________________

[MattS6]

Quick question for you... did you find it easy to get the V12 out? (or is it still in there?!) Do you think the heads need to be removed before attempting removal?

Cheers.

Matt

[Mark Cooper]

Sorry this is so late, I haven't been checking the site lately. To answer your question, the engine is still in. I won't remove it unless replacing it altogether. Unfourtunately, I have found that to remove the Oil pump, I need to take the heads off! The timing covers need to come off as well as the sump to access the oil pump because it is driven by the crank itself. In fact, the oil pump is sandwiched between the timing gear and the first main bearing, so to get it off it looks like I will have to remove the crank itself.

I have taken the sump off three times now and only managed to get the oil pressure from 0 up to 15psi. I changes all the O rings associated with the oil pick up and feed pipes in the sump to get this result. I can find no other problems, no damage anywhere. The pressure is just #### and I don't know why.

I've given up until after Christmas now.

Mark

[Purple AK]

Mark.
I'm not familiar with the V12. But could it be possible that the oil pressure relief valve is stuck, or has something lodged in it! It just seems strange that you lost oil pressure so suddenly. Just a thought! Regards.:tu