LS7 conversion

[ultimacz]

Hi everybody,

on a track day yesterday I met a guy with a brand new Corvette Z06 and got a chance to have a good look at the engine and see (and hear) the car perform. Have to say I am very impressed. He also got a 12 sec. 1/4 mile time, with no previous experiences and no modifications!

Now, referring also to a previous thread, we have checked all available engine/gearbox options and it seems that the LSx route is the way to go. And if LSx, it should be LS7 - out of the box, NO modifications, in order to have a reliable engine.

Now, I am ready to start this project but have no idea what is the right way to do it. No support from the factory, I am afraid, which is a pity. Have got over here very skilled and enthusiastic mechanics, but with no LSx experiences...

Would be grateful for any advices, mainly on

- what has to be done for a SBC to LS7 conversion, in order not to forget on main parts
- will the LS7 fit into the frame, i.e. does it have the same dimensions and fixing points as an LS2 (for example) - I have also noticed that the air intake is directed to the front of the car, i.e. there is not enough space in the Ultima, I suppose...
- what about cooling, alternator, A/C compressor, gas pedal (LS7 uses electronic, no cable), fuel pumps, exhaust system (same as LS2?)
- what about the EFI control, we intend to use a top product (EURO 4 from F1, I think) and set it up locally, using a professional motor sports company and top testing equipment
- what about dry sump (the Z06 tank is pretty big...), anybody to recommend a tank and where to place it?
- adaptor to Getrag 6-speed box with cable shift (same as for other LS2 engines?)

We would like to buy a complete set of components, the installation work and testing can be done locally in Prague.

Any ideas would be great.

Peter

[peterpsg]

ultimacz said:

- what about dry sump (the Z06 tank is pretty big...), anybody to recommend a tank and where to place it?

I think the factory might be able to help you with the Dry sump tank...



I have one just like this on my car, though it's a pain to get the oil in with the rear clip in the way, so I usually pop the 2 gas loaded clip springs off and gently lower the clip onto a suitably soft item placed underneath it...

[splatspeed]

if you want an LS7 get an LS7

as long as you can mate to gearbox then fine

there may be teathing problems with exhaust, engine mounts and gearbox attachments but these can all be overcome as long as you dont try to put SBC parts onto an LS7 should be ok

go for it

[chuntington101]

speack to builder on here! he is currently installing an LS& into his ultima. also LS2 ulitima would be good to talk to as the LS7 and LS2 block are basically the same!

thansk Chris.

[usagtrman]

peterpsg said:

I have one just like this on my car, though it's a pain to get the oil in with the rear clip in the way, so I usually pop the 2 gas loaded clip springs off and gently lower the clip onto a suitably soft item placed underneath it...

I don't mean to hijack the thread but we replaced the factory supplied rear struts with some longer throw units which would make filling the sump easier.....although I don't have a dry sump it makes all engine access easier


Back to the topic at hand..........

Brad Z

>> Edited by usagtrman on Wednesday 10th May 13:13

[crafty]

I have an LS2 going into mine.

This thread has a lot of the info you need - www.pistonheads.com/gassing/topic.asp?p=1&f=20&t=248970&h=0

Engine Mounts - you'll need LS>SB adaptor plates and there are two types of SB mounts - you need these ones They are for an early Chevelle
http://store.summitracing.com/partdet

Harness - "Builder" (Scott) will be able to tell you exactly what is in his car.

AC - you need the Monaro/GTO AC unit with the inlet/outlets on the side (Vette is on the rear)

Definitely spend some time in this forum >>> www.ls1tech.com/forums/ >>>> there is a LOT of good info on there - there are also a few idiots - so make sure you Xreference and check any info if anyone offers their opinion. Everyone on that site is an "LS7 Expert"...

[ultimacz]

peterpsg said:

ultimacz said: - what about dry sump (the Z06 tank is pretty big...), anybody to recommend a tank and where to place it? I think the factory might be able to help you with the Dry sump tank...

I am not sure but I think that the Getrag box is a bit wider than the box on the photo. Maybe there will not be enough space for this tank? Anybody knows? Also, what about the oil volume - does the LS7 use as much oil as an SBC?

[ultimacz]

chuntington101 said:

speack to builder on here! he is currently installing an LS& into his ultima. also LS2 ulitima would be good to talk to as the LS7 and LS2 block are basically the same! thansk Chris.

Does this mean a LS7 would drop right in if somebody had already a LS2 installed? What does "basically" mean? Anybody knows?

[ultimacz]

crafty said:

I have an LS2 going into mine. This thread has a lot of the info you need - www.pistonheads.com/gassing/topic.asp?p=1&f=20&t=248970&h=0 Engine Mounts - you'll need LS>SB adaptor plates and there are two types of SB mounts - you need these ones They are for an early Chevelle http://store.summitracing.com/partdet Harness - "Builder" (Scott) will be able to tell you exactly what is in his car. AC - you need the Monaro/GTO AC unit with the inlet/outlets on the side (Vette is on the rear) Definitely spend some time in this forum >>> www.ls1tech.com/forums/ >>>> there is a LOT of good info on there - there are also a few idiots - so make sure you Xreference and check any info if anyone offers their opinion. Everyone on that site is an "LS7 Expert"...

Thanks for all the responses, guys. I will read the mentioned links and try to contact "Builder", though probably his approach is a bit different because he is building a new car whereas I want to try to convert just the engine from an SBC to a LS7 whilst leaving the rest of the car as much as possible untouched...

BTW, does anybody know a company in Europe which could do the whole conversion turn-key? (and is reliable etc.)

[crafty]

Here's a basic list of what you will need to do, apart from harness and mounts.

1. The LS7 is drive-by-wire. You'll need to change the accelerator pedal. Mine is a 2005 LS2 but I'm running a 2002 Camaro (I think) PCM that is drive by cable. I dont know whether you can do this with the LS7 because of the reluctor wheel - check on LS1tech.
2. The water pump has the inlet/outlet and heater hose locations in different positions. This is easily fixed.
3. If you use a GM PCM you'll need a load of circuits disabled. I would strongly recommend using the PCM that Scott has used - it works.
4. You'll need to find somewhere to mount the PCM. Mine is on the right-hand side tucked up behind the fuel filler. I made 3mm Alloy plates to close in the triangle shape the chassis rails make over the tanks. They have holes cut for the fuel filler to go thru.
5. You power the PCM using the coil positive wire.
6. There's a steam pipe on the front of the engine, I have a second fitting welded into my swirl pot and it vents to there.
7. You need to find some exhaust manifolds - or get some headers made, your old ones will not fit, and you are better off running the exhaust down low with an LS engine as the coil packs are on the rocker covers (unless you move them)
8. You'll need a supercharger and Nitros.
9. You'll need to sort the fuel system out. I am running one fuel pump. I had my tank made with -12 fittings all round. I have the tank linked at the bottom with one set of connections, the other set has a tee piece > reducer to -8 > fuel filter > pump > reducer to -6 > -6 line to the engine.. The fuel return line is all -6, comes out of the engine has a tee at the firewall so the fuel can return to both tanks . Given that I have -12 fittings on the bottom of the tank I feel that this should keep the tanks evenly filled.


I am waiting for the intercooler catch tank which should be ready early next week, then I'll post some pics of the engine and all the plumbing and wiring etc...

[BigAl1]

Lots of things to pay attention to, but to answer your questions....

The engine mounts Crafty linked to need adapter plates bought or fabricated.
The fuel system needs to be setup for single line feed (regulated in tank), or add a return line and regulator from the rails.
The intake manifold can be reversed to avoid the firewall clearance issue. The throttle body needs to be converted to cable operated.
The high LH mounted alternator is awkward, might be better down low on LH side, but belt wrap on the water pump must be considered.
The inlet on the water pump must be trimmed shorter to clear the firewall, and a 90deg fitting installed to aim toward the swirl pot. The water pump outlet at the lower RH is pretty easy connection to the RH radiator coolant pipe.
As Crafty said, the GTO A/C compressor has the ports on the side. This helps with clearance vs the SBC chassis tubes, and the engine mounts/adapter plates. The A/C compressor will probably need to be spaced out from the engine to clear the engine mounts.
The exhaust is unknown at this time for the LS7, but Crafty has C6 Vette manifolds on his LS2 and they fit the SBC chassis. I'm waiting for a set of these, plus '00-'02 Camaro manifolds as an experiment to see if they fit. These are both a down path design, not up-and-over like the factory SBC headers.
I don't know of LSx to Getrag 6spd adapter available yet.
See www.ultimagtr.ca for details as I'm going through the final issues before first startup on my LS1/G5003 setup. Many of my challenges will be relevant.
Allan

[usagtrman]

usagtrman said:

peterpsg said: I have one just like this on my car, though it's a pain to get the oil in with the rear clip in the way, so I usually pop the 2 gas loaded clip springs off and gently lower the clip onto a suitably soft item placed underneath it... I don't mean to hijack the thread but we replaced the factory supplied rear struts with some longer throw units which would make filling the sump easier.....although I don't have a dry sump it makes all engine access easier Back to the topic at hand.......... Brad Z >> Edited by usagtrman on Wednesday 10th May 13:13

Sorry to go back off topic again but a friend reminded me that the length of the factory supplied struts were carefully researched so as to pass your SVA requirements. It's not that a longer version wouldn't work.....obviously it did in my case....but the facory has optimized the canopy opening whilst still meeting the requirement to be able to see the tailights with it open. Smart guys those Marlows So don't change your struts without checking the rules first!

Sorry for the confusion .............Back to topic.

Brad Z

[GTRene]

ultimacz said:

Thanks for all the responses, guys. I will read the mentioned links and try to contact "Builder", though probably his approach is a bit different because he is building a new car whereas I want to try to convert just the engine from an SBC to a LS7 whilst leaving the rest of the car as much as possible untouched... BTW, does anybody know a company in Europe which could do the whole conversion turn-key? (and is reliable etc.)

I think there are at least 2 not that far from your place in Europa! here are they...

www.grasser-racing.com/ultima_parts.htm

and

www.technocars.de/index-engl.htm

have fun, and you know that LS7 is the way to go "trouble free" and lots of modern power!
cheers GTRene

[ultimacz]

Thanks for all the replies.

That project looks to be very, very demanding. Many parts need to be exchanged or modified or made on order. A bit of "try and error", as it seems. Would be my dream if somebody had a complete solution which would just drop in. But that is obviously not going to happen. (Though I still dont understand - many Ultima owners must think the same way once they go through all the usual SBC problems, so why did nobody develop a LSx solution, not even the factory??)

Worst thing is I am not a mechanic, only financing it. Although money is not really an issue, that does not help me if there is no solution available...

Will have to consider all pros and cons. Maybe it would be best to sell the Ultima as it is. Would hate to invest another year or two, just to find me then in the same position as today...

Will let you know.
Thanks,

Peter

[GTWayne]

Peter, I was in a similar situation myself nearly 5 years ago in as much as I have had to wait a. for my engine to be built b. for the car itself to be built (not my original plan as I had wanted to build the car myself but being over comitted with my work and then having a serious accident this was no longer an option)the point I am trying to make is don't abandon your project because things are difficult,change,adapt,alter your specification and maybe after you have enjoyed the car for a while look at installing a LS7 motor later as an upgrade?Keep the faith and good luck!

[chuntington101]

good point! enjoye the car now and keep an eye on the LS7/LS2 installs! also look at the Magnus supercharged LS2 as i thinkthey would destory the LS7 (unmodded) and would probalbe be a smilier price!

thanks CHris.

[ultimacz]

GTWayne said:

Peter, I was in a similar situation myself nearly 5 years ago in as much as I have had to wait a. for my engine to be built b. for the car itself to be built (not my original plan as I had wanted to build the car myself but being over comitted with my work and then having a serious accident this was no longer an option)the point I am trying to make is don't abandon your project because things are difficult,change,adapt,alter your specification and maybe after you have enjoyed the car for a while look at installing a LS7 motor later as an upgrade?Keep the faith and good luck!

Thanks, fair point.
Maybe it is just because I am in a bad mood right now. After investing 3 years in a try&error approach to get the car reliable, I thought I am through the worst, at least for this years season. Heat (cooling) is now completely under control (could spend the whole day in slow traffic...), it does not stall under breaking nor when A/C is switched on, alternator and A/C compressor dont fall off, A/C cools a bit more than just itself, distributor gear does not get eaten, my new custom bushes do not wear, it does not leak, battery does not run low, starter does its job even when hot, etc, etc, and the engine revs up to 7.200 without any hesitation, air fuel ratio is near perfect at between 12,5 to 13,5 (though its carbed), goes like a bloody rocket... Could be happy right now.

But some weeks ago it started again: First the ignition failed, after a long story we found that the control box (MSD) failed (though not always because once towed back to the garage it would of course start again...). Then it started to eat oil, not the normal 3-4 litres per 1000km, but 1 litre per 100 km, accompanied by heavy smoking during longer idling (but not visibly during acceleration/decelaration). Of course we did all tests, compression and leak down, vaccuum readings, ignition - everything spot-on. Still it smokes like a chimney in slow traffic, really embarrassing.
Last evening then it was really too much: I kept the oil level at min. and switched off the Accusump (when it was full) to test whether there would not be too much oil in the pan leading to a higher oil consumption (some of the "specialists" guessed it would have something to do with too much oil and Accusump in general, and not having dry sump...). Whilst less oil in the pan did not lead to much less smoking, I failed to notice during the drive home that the oil pressure dropped to approx. 0,5 bar during braking, because the pump simply ran out of oil, and the Accusump was switched off. You might ask why I did not notice that earlier, there is an oil control light - as I found out later this oil control light is broken, does not work (two days ago it did, of course), that is really bad luck or the car simply hates me. After filling in 2 litres of oil (the pressure recovered then to full) and wondering whether I have destroyed now some bearings or other internals, the front lights went dead (and no, its not the fuse nor the cable connectors, probably the light switch), I drove home in complete darkness.

Sorry for this exhausting story but I am really p***ed off. Maybe the problem is that I drive the car regularly and have done relatively high mileage (approx. 12.000 mls).

Now, to come back to your suggestion about enjoying the car and waiting: the car is now again in my mechanics garage, waiting for the engine to be pulled out. It will be really hard to justify just another rebuild, because I feel that every dollar invested into this engine is a waste. On the other hand there is still no alternative, at least if I want to drive the car still a bit this year.

Have to say that I still love my Ultima like crazy, whilst many of my friends drive Ferraris or Porsches with much less problems (though not without problems, to be fair). If the Ultima would just reward my efforts with a bit more reliability. (and dont forget, the car is fully factory build, so build quality was surely ok). In the end I think it is really about the SBC engine concept.

Ok, end of complaining, anyway I know my nightmare will continue, I will put more and more efforts into that, making my family and friends wonder whether I have not gone nuts.

Last comment: Had a new Carrera 4S, great car, but did not like it - SOO BORING. Long live the Ultima!

[crafty]

Jeff can do a drop in conversion for you. I had him put my engine together and dyno it to make sure everything worked.

He has an LS2 in his.

He can send you every pipe and fitting needed - your mechanic will be able to fix it. Its not that hard and surely beats the headache of continual problems with a SB engine.

The SB's are running cams and a reasonable amount of valve overlap to get over 400hp. The LS2 will put this out in stock trim.

If you want to chat about it PM me and I'll send you my phone number.

[GTRene]

ultimacz said:

Thanks, fair point. Maybe it is just because I am in a bad mood right now. After investing 3 years in a try&error approach to get the car reliable, I thought I am through the worst, at least for this years season. Heat (cooling) is now completely under control (could spend the whole day in slow traffic...), it does not stall under breaking nor when A/C is switched on, alternator and A/C compressor dont fall off, A/C cools a bit more than just itself, distributor gear does not get eaten, my new custom bushes do not wear, it does not leak, battery does not run low, starter does its job even when hot, etc, etc, and the engine revs up to 7.200 without any hesitation, air fuel ratio is near perfect at between 12,5 to 13,5 (though its carbed), goes like a bloody rocket... Could be happy right now. But some weeks ago it started again: First the ignition failed, after a long story we found that the control box (MSD) failed (though not always because once towed back to the garage it would of course start again...). Then it started to eat oil, not the normal 3-4 litres per 1000km, but 1 litre per 100 km, accompanied by heavy smoking during longer idling (but not visibly during acceleration/decelaration). Of course we did all tests, compression and leak down, vaccuum readings, ignition - everything spot-on. Still it smokes like a chimney in slow traffic, really embarrassing. Last evening then it was really too much: I kept the oil level at min. and switched off the Accusump (when it was full) to test whether there would not be too much oil in the pan leading to a higher oil consumption (some of the "specialists" guessed it would have something to do with too much oil and Accusump in general, and not having dry sump...). Whilst less oil in the pan did not lead to much less smoking, I failed to notice during the drive home that the oil pressure dropped to approx. 0,5 bar during braking, because the pump simply ran out of oil, and the Accusump was switched off. You might ask why I did not notice that earlier, there is an oil control light - as I found out later this oil control light is broken, does not work (two days ago it did, of course), that is really bad luck or the car simply hates me. After filling in 2 litres of oil (the pressure recovered then to full) and wondering whether I have destroyed now some bearings or other internals, the front lights went dead (and no, its not the fuse nor the cable connectors, probably the light switch), I drove home in complete darkness. Sorry for this exhausting story but I am really p***ed off. Maybe the problem is that I drive the car regularly and have done relatively high mileage (approx. 12.000 mls). Now, to come back to your suggestion about enjoying the car and waiting: the car is now again in my mechanics garage, waiting for the engine to be pulled out. It will be really hard to justify just another rebuild, because I feel that every dollar invested into this engine is a waste. On the other hand there is still no alternative, at least if I want to drive the car still a bit this year. Have to say that I still love my Ultima like crazy, whilst many of my friends drive Ferraris or Porsches with much less problems (though not without problems, to be fair). If the Ultima would just reward my efforts with a bit more reliability. (and dont forget, the car is fully factory build, so build quality was surely ok). In the end I think it is really about the SBC engine concept. Ok, end of complaining, anyway I know my nightmare will continue, I will put more and more efforts into that, making my family and friends wonder whether I have not gone nuts. Last comment: Had a new Carrera 4S, great car, but did not like it - SOO BORING. Long live the Ultima!

Sorry to hear all this...that would be way to much for me to stand through... I also wonder why Ultima only does the old!!!! SBC almost runs like a race car great sound too but race cars only do a few races and then they also have to rebuild, but if you want a racecar for the road you realy want some reliabillity!
The LS7 is still new and a realy nice engine! but to less info and material for the Ultima.
When I was you I would sell your Ultima(when fixed again and again) and buy one with the audi engine from technocars, or by a even nicer?? one with the BMW M5 engine in it?! or when your engine still needs to get that rebuild save the money trailer your car to that German M5 Ultima builder en put in their more reliable engine?
here their link;
www.mlr-racetec.com/gtr600.html

In the mean time I also have a nice car for you only 280 build and 3 in NL see my link:

www.pistonheads.com/sales/46967.htm

have fun and let us now what you do, I'm maybe interested in your car, but have to sell mine first.
cheers
GTRene

[BigAl1]

Peter,
Don't be put off by the amount of details to modify! It can be done, and with more LSx/Ultima installs happening, the details will be worked out over time. I started this path with little guidance, having only seen Jeff S.' GTR with LS6. Now there are 7 I can easily think of that are using LSx engines, and must be more out there. It just takes some planning and research. I think your biggest hurdle is the LSx/Getrag adapter - AFAIK they don't exist yet. Maybe a call to Kennedy Engineering will solve that?
Allan