LS7 Conversion?

[LuckyP]

Not good news from Charles Dunn when he stripped my 'tired' engine. Looks terminal.

I had hoped that I could have a spectacular track failure, but it looks like it just whimpered off into a corner and died.

I'm going LS7. Has anyone done the conversion yet?

Soup to nuts, what is the cost all in. Did we say around £25K??

Spose I'd better go 650 bhp while I'm at it.

Lucky

[gtr-gaz]

Sorry to hear that Pete, although I expext you have mixed feelings?

Pleased you finally have the excuse to go LS7 and yet, sad to have to shell out about £25k?

I picked up a list of what you need to buy for the LS7 conversion while at Stoneleigh last year. I think it ran to 2 pages! Everything bar the gearbox will need to be replaced, including the adapter plate. Ring the factory in the morning and get them to send it to you.

Good luck with it At least you should now be able to crack the 200mph barrier!

If money is no object, why not go for twin turbos while you are at it??

[bluesatin]

Lucky,

Had a look at the engine yesterday and looks like continuous track use (using the standard double pumper) was the cause of the detonation problems. The engine still has a very health bottom end (no problems on the bearings) and heads so I would get it rebuilt with the new carb (Crazy has proven how much better these are on the road and track)and have a dry sump fitted. £4K rather than £25K

[LuckyP]

200mph. Hmmm. And there I was having decided to go back to the old G50 03 ratios after the awful 4th and 5th gear swap experiment.

Well I spose a full set of perfectly matched G50 ratios could be on the cards if it doesn't compromise that track performance.......But I guess it will.

What can these here LS7s rev to......erm...'safely'?

[SchimmS]

Hallo Herr Peter,

I`ve just recently done a conversion from the older LS6 (5,7l 405hp) to the 650hp LS7. Basically it`s a total conversion like you`re planning to do (no difference there between previously installed engines).
The good thing about it is that with the factory supplied LS7 kit it`s really easy to do.
The AS supplied LS7 has a rev limit of 7.500 rpm (at least that`s the last figure on the dyno sheet)
I also took some photos that might be of some help..


Cheers,
Sven

Edited by SchimmS on Sunday 20th January 08:49

[crafty]

Why not get a built LS engine?

[kylemrushall]

bluesatin said:

Lucky,

Had a look at the engine yesterday and looks like continuous track use (using the standard double pumper) was the cause of the detonation problems. The engine still has a very health bottom end (no problems on the bearings) and heads so I would get it rebuilt with the new carb (Crazy has proven how much better these are on the road and track)and have a dry sump fitted. £4K rather than £25K

That doesnt sound terminal?? The old carbs borewashing again??

It sounds like an excuse to me Pete i think you just want some justification to go with the LS7, but i dont blame you.

A rebuild with EFI and dry sump would be cheaper but me thinks your heart is set on the LS route sooner or later?

[bluesatin]

Not bore wash but running to lean and then detonating according to the man that knows! Standard carbs are fine for road use but when you track a lot I would change to the HP Carb. I have a suggestion for the old block if you go down the LS route.

Chevy engine in your 911. Should cost less than £1000, weighs around the same as a turbo engine and will make a very interesting 964!

http://www.renegadehybrids.com/indexx.html

[LuckyP]

You are a naught man Guy, putting these thoughts in my head.

Surely the SBC is heavier, higher and further back - three things you don't want in a Porsche chassis??

[bluesatin]

I have had this discussion before and the SBC with ali heads is a little less than the water cooled engines and a little more than the air cooled but the same as a turbo air cooled but a lot more powerful! I think it makes the ideal solution and save you money on the long run. Now if you went for a Dart block then you have a better weight distribution!

[leo-786]

LuckyP said:

Soup to nuts, what is the cost all in. Did we say around £25K??
Lucky

The amerspeed ls7 650 bhp costs $26k, in that case about £14k.

notice the money sign.

[SchimmS]

leo-786 said:

LuckyP said:

Soup to nuts, what is the cost all in. Did we say around £25K??
Lucky

The amerspeed ls7 650 bhp costs $26k, in that case about £14k.

notice the money sign.

Don`t forget the cost for the engine bay parts that need to be replaced, i.e. fuel system, exhaust system (with cats), dry sump oil system (+ oil cooler), fly-by-wire throttle (pedal), wiring harness, etc.

[Davrianman]

Hi Lucky,

Have you seen the LS7 in the Gardner Douglas Lola T70? There prices are pretty good and they will do a turnkey solution...

Mart

[mogg]

" Standard carbs are fine for road use but when you track a lot I would change to the HP Carb. "

Do you have details of the HP Carb and can you buy them in the UK anywhere ?

Thanks

[kylemrushall]

Standard carbs are fine for road use


Thats a matter of opinion!!!

[XTR2Turbo]

LuckyP

I am 75% through converting my GTR from SBC to LS7. Should be finished (subject to final mapping) around end of Feb.

It is photos of my engine on Peter Knights website.

I definitely think LS is the route to go. PM me if you want a chat.

I think a stock LS7 will rev to around 7200 rpm but I understand that the power starts falling away above about 5500.

David

Edited by XTR2Turbo on Monday 21st January 22:41

[LuckyP]

Been doing a bit of thinking and I'm not so sure that £25K is sensible for what I do with the thing. I'm investigating a few avenues.....all of which are dry sumped!!

Going to Charles Dunns gaff on Saturday morning to take a few pics of the carnage(which includes a cracked main bearing cap for starters!!)

Thanks for all the e-mailed and posted advice chaps.

Lucky

[ROWDYRENAULT]

P: good luck on your LS7 project.After speaking to some folks at P.R.I. the race car show in Orlando fl. I would consider the following. There seems to be a concern that the stock dry sump pan on the LS7 might not be the best for lots of track work. A.R.E. makes a gorgeous pan that might help in the long run. The factory headers for the ls series are ok but I think you could do better. The 650 hp level in the LS7 is attainable but the last 50 hp are going to be exspensive. Before you go any further I would invest in a call to Jeff Schwartz. the figures that I see quoted for the LS7 in England and Amerspeed seem a bit high. Also if you had a chance you might ask Jeff what a World Products LS style Warhawk block and head combo with after market internals might get you. I think the World block will go to 440 cubic inchs. Yes it would be exspensive but he World design goes beyond the LS in several areas like more head bolts better valve angle ect. Consider Motec engine managment the stuff is bulitt proof. In know some of this is out on the edge but this car is about dreams not always reality. lee

[LuckyP]

Ok, so I bottled it. A/S were given the brief of a track motor rather than the std road engine and are sending Charles Dunn the following:

Dry sump kit which includes belt, #12 line fittings, 10 ft. of #12 braided hose, oil inlet filter adapter, pump, sump, PM alternator, pulleys, bracket and adapters, in line oil filters $2234.00
Steel main caps and studs, shipping $294.25
Oil pump block off $16.00
Gaskets $196.00
Comp poly dist. gear for roller cam $128.00
Teflon coated main bearings $135.00
Teflon coated rod bearings $135.00
Teflon coated cam bearings $56.00
Rod bolts $96.00/set
Chamfer rod bearings $30.00
Steel roller cam-custom grind $325.00
Roller lifters $302.00
Comp roller rockers $306.00
Girdle $205.00
Cloyes steel roller timing set $160.00
Pistons $604.00
Head stud kit $250.00
Oil gallery plugs $5.00
Valves $482.00
Keepers $26.00
Titanium retainers $275.00

We can rebuild her.........

Going for the Holley HP Carb and Factory dry sump kit.

If (when) this goes pop. I'll fink LS7 again.

Lucky

[bluesatin]

You know it makes sense! Any idea on power gains for this lot. I know the carb gives 10bhp due better breathing and cam maybe 20 bhp- anything else in the package!

All looks like a great package and look forward to the dry sump and see how it goes.