Sponsors or Tech heads- Help me build a Road Race Motor
09-02-2010, 12:14 AM
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Sponsors or Tech heads- Help me build a Road Race Motor Not sure the right place to post this, but this seems the best location.
So here is an engine build to consider. I'm looking for engine builders and tech fanatics to chime in if possible. Sponsor are welcome to PM me. I’m not going to do anything until December though. I’m looking for opinions and ideas for the right direction to go with this. The car is an LS powered road race RX7. This car sees 0 street miles, weighs 2650lbs.
So at the end of this season our current 372cu in (3.9 x 3.9) LS1 based motor is about done. We’ve raced it all season and it has performed very well, but the leakdown numbers are starting to get high, and it’s a 1998 block which limits honing. Top that off with CNC’d 806 heads and it makes sense to start new. It’s been in the car since 1999 as a street, drag race, autocross and now a season of road racing, so I think it’s done very well. The current motor makes 460/435 at the wheels so not too bad. That’s with a 3 stage dry sump, 230/230 XER on a 115 and a ported Fast 92/92.
I’ve been reading a bunch and I’m trying to figure out what the basis for the next engine should be. I run SCCA ITE which is kind of an anything goes sort of class. I have no restrictions on cu in, compression, cam type, or type of gas. I currently run 100 unlead. I could run 110 octane, but it would be leaded.
So I’m trying to get the most reliable HP I can, but this is road racing so other considerations need to be addressed as well. The races are 30 minutes, and rpm is pretty high. The motor will continue to be dry sumped.
Generally the RPM range is 3200 to 7000. Our current motor iredlines at 7000, but I shift it at 6500 as much as possible.
My thoughts for the next motor are something like this but are by far from set in stone. I'm willing to listen as I know there is a lot I don't know.
7000 RPM redline. This helps our gearing issues.
400-440 cu in
LS3 – LS7 block or sleeved? - I’m torn here. The LS3 is quite a bit less money, but they have all kinds of reported oiling issues. I can push 1.8G corners and 1.4G braking, so oiling issues are a big concern. I also have concern running a 4.0” crank in the LS3 with road racing. The bore is pretty short and with a lot of sustained RPM I have concerns about longevity. I know a lot of people are running them without issues, but nobody I’m aware of is seriously road racing one. Not sure that’s warranted, but it's a concern all the same. The LS7 block has much longer bores, but has been know to crack liners. The other option is a sleeved block, but which one, and wet or dry? I have an extra 2001 LS1 block already, so that is an option. Thoughts? How long a stroke can I use on an LS3, LS7 and sleeved block with road racing in mind - And rebuilds in the future?
Callies crank and rods – I think these are better than Eagle, but not too expensive.
Compression - What compression should I shoot for with 100 octane unlead or should I use leaded 110?
Heads
Another place I’m torn. LS3 heads seem to be great, but they have very close P/V clearances with bigger cams. With custom pistons this shouldn’t be an issue, but tight tolerances worry me. The TrickFlow/AFR cathedral heads seem to be the other option, and from all reports make a lot more low and midrange torque which is very important to me. Pulling out of corners at 3400 RPM is common and low end torque (3000 RPM+) turns faster laps for sure. I also already have a Vengeance ported FAST 92/92 so that is also a consideration. Light valve train is a given. I’m thinking LS3 hollow valves, etc…
Lifters – What is best for road racing? Are LS7 lifters good enough, or?
Cams –
I’ll probably work with the engine builder or Patrick G for the cam. He did one for my Ultima GTR and it worked well.
Rebuilds – So how many hours or miles (hours are a better measure I think) can I go between teardowns, and what needs to be looked at. Valve springs for sure, but what should the interval be on bearings, lifters, timing chains rings, etc…? A yearly teardown I kind of expect, but I’m going to be unhappy if it blows mid season.
Cost – Always the deciding factor. I would like to keep the build to 12-13k or less if possible. This is with using my existing ECU, pan, dry sump and intake/ throttle body and accessories.
So here is an engine build to consider. I'm looking for engine builders and tech fanatics to chime in if possible. Sponsor are welcome to PM me. I’m not going to do anything until December though. I’m looking for opinions and ideas for the right direction to go with this. The car is an LS powered road race RX7. This car sees 0 street miles, weighs 2650lbs.
So at the end of this season our current 372cu in (3.9 x 3.9) LS1 based motor is about done. We’ve raced it all season and it has performed very well, but the leakdown numbers are starting to get high, and it’s a 1998 block which limits honing. Top that off with CNC’d 806 heads and it makes sense to start new. It’s been in the car since 1999 as a street, drag race, autocross and now a season of road racing, so I think it’s done very well. The current motor makes 460/435 at the wheels so not too bad. That’s with a 3 stage dry sump, 230/230 XER on a 115 and a ported Fast 92/92.
I’ve been reading a bunch and I’m trying to figure out what the basis for the next engine should be. I run SCCA ITE which is kind of an anything goes sort of class. I have no restrictions on cu in, compression, cam type, or type of gas. I currently run 100 unlead. I could run 110 octane, but it would be leaded.
So I’m trying to get the most reliable HP I can, but this is road racing so other considerations need to be addressed as well. The races are 30 minutes, and rpm is pretty high. The motor will continue to be dry sumped.
Generally the RPM range is 3200 to 7000. Our current motor iredlines at 7000, but I shift it at 6500 as much as possible.
My thoughts for the next motor are something like this but are by far from set in stone. I'm willing to listen as I know there is a lot I don't know.
7000 RPM redline. This helps our gearing issues.
400-440 cu in
LS3 – LS7 block or sleeved? - I’m torn here. The LS3 is quite a bit less money, but they have all kinds of reported oiling issues. I can push 1.8G corners and 1.4G braking, so oiling issues are a big concern. I also have concern running a 4.0” crank in the LS3 with road racing. The bore is pretty short and with a lot of sustained RPM I have concerns about longevity. I know a lot of people are running them without issues, but nobody I’m aware of is seriously road racing one. Not sure that’s warranted, but it's a concern all the same. The LS7 block has much longer bores, but has been know to crack liners. The other option is a sleeved block, but which one, and wet or dry? I have an extra 2001 LS1 block already, so that is an option. Thoughts? How long a stroke can I use on an LS3, LS7 and sleeved block with road racing in mind - And rebuilds in the future?
Callies crank and rods – I think these are better than Eagle, but not too expensive.
Compression - What compression should I shoot for with 100 octane unlead or should I use leaded 110?
Heads
Another place I’m torn. LS3 heads seem to be great, but they have very close P/V clearances with bigger cams. With custom pistons this shouldn’t be an issue, but tight tolerances worry me. The TrickFlow/AFR cathedral heads seem to be the other option, and from all reports make a lot more low and midrange torque which is very important to me. Pulling out of corners at 3400 RPM is common and low end torque (3000 RPM+) turns faster laps for sure. I also already have a Vengeance ported FAST 92/92 so that is also a consideration. Light valve train is a given. I’m thinking LS3 hollow valves, etc…
Lifters – What is best for road racing? Are LS7 lifters good enough, or?
Cams –
I’ll probably work with the engine builder or Patrick G for the cam. He did one for my Ultima GTR and it worked well.
Rebuilds – So how many hours or miles (hours are a better measure I think) can I go between teardowns, and what needs to be looked at. Valve springs for sure, but what should the interval be on bearings, lifters, timing chains rings, etc…? A yearly teardown I kind of expect, but I’m going to be unhappy if it blows mid season.
Cost – Always the deciding factor. I would like to keep the build to 12-13k or less if possible. This is with using my existing ECU, pan, dry sump and intake/ throttle body and accessories.
09-02-2010, 09:17 AM
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I ran my LS2 402 for two seasons with NASA Texas in TTU. The weekends consist of four 20 minute practice sessions and four 20 minute timed sessions. I never had any issues and I was running Hoosier slicks (VRL 305's on all four corners) not sure of my G's but I run a coil-over setup and poly bushings throughout with a half cage strengthening the chasis in front of the rear wheels.
I can say the LS2 has been great and it is a 4" bore and 4" stroke. If you want more details I can provide the build sheet. In race spec this motor made over 500 RWHP and butt loads of torque... It was nothing to see 140+ on the long straight at Texas World Speedway (could've have stretched it for more but my cajones weren't big enough) and now here on the east coast at Summit Point I do alot of back pedaling because the car exceeds my skill level.
All that to say I believe the LS2 block can provide you an awesome foundation if prepped right. Oh my build ran about $9000 for the motor, everything else kicked me in the teeth but the motor was cheap comparatively speaking.
I can say the LS2 has been great and it is a 4" bore and 4" stroke. If you want more details I can provide the build sheet. In race spec this motor made over 500 RWHP and butt loads of torque... It was nothing to see 140+ on the long straight at Texas World Speedway (could've have stretched it for more but my cajones weren't big enough) and now here on the east coast at Summit Point I do alot of back pedaling because the car exceeds my skill level.
All that to say I believe the LS2 block can provide you an awesome foundation if prepped right. Oh my build ran about $9000 for the motor, everything else kicked me in the teeth but the motor was cheap comparatively speaking.
09-03-2010, 08:08 AM
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Not sure the right place to post this, but this seems the best location.
So here is an engine build to consider. I'm looking for engine builders and tech fanatics to chime in if possible. Sponsor are welcome to PM me. I’m not going to do anything until December though. I’m looking for opinions and ideas for the right direction to go with this. The car is an LS powered road race RX7. This car sees 0 street miles, weighs 2650lbs.
So at the end of this season our current 372cu in (3.9 x 3.9) LS1 based motor is about done. We’ve raced it all season and it has performed very well, but the leakdown numbers are starting to get high, and it’s a 1998 block which limits honing. Top that off with CNC’d 806 heads and it makes sense to start new. It’s been in the car since 1999 as a street, drag race, autocross and now a season of road racing, so I think it’s done very well. The current motor makes 460/435 at the wheels so not too bad. That’s with a 3 stage dry sump, 230/230 XER on a 115 and a ported Fast 92/92.
I’ve been reading a bunch and I’m trying to figure out what the basis for the next engine should be. I run SCCA ITE which is kind of an anything goes sort of class. I have no restrictions on cu in, compression, cam type, or type of gas. I currently run 100 unlead. I could run 110 octane, but it would be leaded.
So I’m trying to get the most reliable HP I can, but this is road racing so other considerations need to be addressed as well. The races are 30 minutes, and rpm is pretty high. The motor will continue to be dry sumped.
Generally the RPM range is 3200 to 7000. Our current motor iredlines at 7000, but I shift it at 6500 as much as possible.
My thoughts for the next motor are something like this but are by far from set in stone. I'm willing to listen as I know there is a lot I don't know.
7000 RPM redline. This helps our gearing issues.
400-440 cu in
LS3 – LS7 block or sleeved? - I’m torn here. The LS3 is quite a bit less money, but they have all kinds of reported oiling issues. I can push 1.8G corners and 1.4G braking, so oiling issues are a big concern. I also have concern running a 4.0” crank in the LS3 with road racing. The bore is pretty short and with a lot of sustained RPM I have concerns about longevity. I know a lot of people are running them without issues, but nobody I’m aware of is seriously road racing one. Not sure that’s warranted, but it's a concern all the same. The LS7 block has much longer bores, but has been know to crack liners. The other option is a sleeved block, but which one, and wet or dry? I have an extra 2001 LS1 block already, so that is an option. Thoughts? How long a stroke can I use on an LS3, LS7 and sleeved block with road racing in mind - And rebuilds in the future?
Callies crank and rods – I think these are better than Eagle, but not too expensive.
Compression - What compression should I shoot for with 100 octane unlead or should I use leaded 110?
Heads
Another place I’m torn. LS3 heads seem to be great, but they have very close P/V clearances with bigger cams. With custom pistons this shouldn’t be an issue, but tight tolerances worry me. The TrickFlow/AFR cathedral heads seem to be the other option, and from all reports make a lot more low and midrange torque which is very important to me. Pulling out of corners at 3400 RPM is common and low end torque (3000 RPM+) turns faster laps for sure. I also already have a Vengeance ported FAST 92/92 so that is also a consideration. Light valve train is a given. I’m thinking LS3 hollow valves, etc…
Lifters – What is best for road racing? Are LS7 lifters good enough, or?
Cams –
I’ll probably work with the engine builder or Patrick G for the cam. He did one for my Ultima GTR and it worked well.
Rebuilds – So how many hours or miles (hours are a better measure I think) can I go between teardowns, and what needs to be looked at. Valve springs for sure, but what should the interval be on bearings, lifters, timing chains rings, etc…? A yearly teardown I kind of expect, but I’m going to be unhappy if it blows mid season.
Cost – Always the deciding factor. I would like to keep the build to 12-13k or less if possible. This is with using my existing ECU, pan, dry sump and intake/ throttle body and accessories.
So here is an engine build to consider. I'm looking for engine builders and tech fanatics to chime in if possible. Sponsor are welcome to PM me. I’m not going to do anything until December though. I’m looking for opinions and ideas for the right direction to go with this. The car is an LS powered road race RX7. This car sees 0 street miles, weighs 2650lbs.
So at the end of this season our current 372cu in (3.9 x 3.9) LS1 based motor is about done. We’ve raced it all season and it has performed very well, but the leakdown numbers are starting to get high, and it’s a 1998 block which limits honing. Top that off with CNC’d 806 heads and it makes sense to start new. It’s been in the car since 1999 as a street, drag race, autocross and now a season of road racing, so I think it’s done very well. The current motor makes 460/435 at the wheels so not too bad. That’s with a 3 stage dry sump, 230/230 XER on a 115 and a ported Fast 92/92.
I’ve been reading a bunch and I’m trying to figure out what the basis for the next engine should be. I run SCCA ITE which is kind of an anything goes sort of class. I have no restrictions on cu in, compression, cam type, or type of gas. I currently run 100 unlead. I could run 110 octane, but it would be leaded.
So I’m trying to get the most reliable HP I can, but this is road racing so other considerations need to be addressed as well. The races are 30 minutes, and rpm is pretty high. The motor will continue to be dry sumped.
Generally the RPM range is 3200 to 7000. Our current motor iredlines at 7000, but I shift it at 6500 as much as possible.
My thoughts for the next motor are something like this but are by far from set in stone. I'm willing to listen as I know there is a lot I don't know.
7000 RPM redline. This helps our gearing issues.
400-440 cu in
LS3 – LS7 block or sleeved? - I’m torn here. The LS3 is quite a bit less money, but they have all kinds of reported oiling issues. I can push 1.8G corners and 1.4G braking, so oiling issues are a big concern. I also have concern running a 4.0” crank in the LS3 with road racing. The bore is pretty short and with a lot of sustained RPM I have concerns about longevity. I know a lot of people are running them without issues, but nobody I’m aware of is seriously road racing one. Not sure that’s warranted, but it's a concern all the same. The LS7 block has much longer bores, but has been know to crack liners. The other option is a sleeved block, but which one, and wet or dry? I have an extra 2001 LS1 block already, so that is an option. Thoughts? How long a stroke can I use on an LS3, LS7 and sleeved block with road racing in mind - And rebuilds in the future?
Callies crank and rods – I think these are better than Eagle, but not too expensive.
Compression - What compression should I shoot for with 100 octane unlead or should I use leaded 110?
Heads
Another place I’m torn. LS3 heads seem to be great, but they have very close P/V clearances with bigger cams. With custom pistons this shouldn’t be an issue, but tight tolerances worry me. The TrickFlow/AFR cathedral heads seem to be the other option, and from all reports make a lot more low and midrange torque which is very important to me. Pulling out of corners at 3400 RPM is common and low end torque (3000 RPM+) turns faster laps for sure. I also already have a Vengeance ported FAST 92/92 so that is also a consideration. Light valve train is a given. I’m thinking LS3 hollow valves, etc…
Lifters – What is best for road racing? Are LS7 lifters good enough, or?
Cams –
I’ll probably work with the engine builder or Patrick G for the cam. He did one for my Ultima GTR and it worked well.
Rebuilds – So how many hours or miles (hours are a better measure I think) can I go between teardowns, and what needs to be looked at. Valve springs for sure, but what should the interval be on bearings, lifters, timing chains rings, etc…? A yearly teardown I kind of expect, but I’m going to be unhappy if it blows mid season.
Cost – Always the deciding factor. I would like to keep the build to 12-13k or less if possible. This is with using my existing ECU, pan, dry sump and intake/ throttle body and accessories.
i would build a 427 with a smallish head-like a trickflow 235 or a PI 245-this will give you a wide powerband with good tq off the corner and good top end power.
the valvetrain is where you really need to make sure everything is good-this needs to be a matched system-not a cam from this guy,and springs from another.I would def use a camshaft with a softer lobe,tie bar lifters are a good idea,lightweight springs,and a very ridgid rocker arm-perferably a shaft rocker.
you should keep your compression around 11.7 using 100 octane fuel,the leaded fuel is going to screw up your o2 sensors.
I hope this helps some
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09-03-2010, 08:53 AM
#8
Please shoot me a pm when you get some time. I'd like the opportunity to put together a complete estimate for you. I have a few ideas we can discuss to hopefully put together a package that will meet your goals & budget. 
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
09-04-2010, 06:04 PM
#9
I'm sure all of the builders that have posted above are capable of putting together a great motor for you. From the experience from my new combo you are going to have to deal with alot more heat so plan on a oil cooler and bigger rad. I originally had stainless headers but latter on had them coated to cut down on the under hood temps. A dry sump is going to on your list as well.
