C5-R Block
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
C5-R Block
Okay CF,
I ended up getting a C5.R block from a deal that I worked out. I think this is more of a novelty these days since there are many options for the LS platform;
Dart, GM Bowtie LSX, LSR, RHS to name a few. I'm not sure this block is produced anymore and definitely didn't pay the $9K retail for it.
Anyways this is a 4 bolt head block and is priced higher than much better blocks from mentioned above.
Has billet steel caps, its been "hipped" and max bore/stroke is 4.160/4.100.
So I plan on having a 427" LS7 headed (Katech spec'd LS7 heads valves/guides, springs etc.) motor at 13:1 compression ratio. Hoping to get 705 flywheel (short travel lifters, sever duty rocker shaft, etc.).
I ended up getting a C5.R block from a deal that I worked out. I think this is more of a novelty these days since there are many options for the LS platform;
Dart, GM Bowtie LSX, LSR, RHS to name a few. I'm not sure this block is produced anymore and definitely didn't pay the $9K retail for it.
Anyways this is a 4 bolt head block and is priced higher than much better blocks from mentioned above.
Has billet steel caps, its been "hipped" and max bore/stroke is 4.160/4.100.
So I plan on having a 427" LS7 headed (Katech spec'd LS7 heads valves/guides, springs etc.) motor at 13:1 compression ratio. Hoping to get 705 flywheel (short travel lifters, sever duty rocker shaft, etc.).
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Okay CF,
I ended up getting a C5.R block from a deal that I worked out. I think this is more of a novelty these days since there are many options for the LS platform;
Dart, GM Bowtie LSX, LSR, RHS to name a few. I'm not sure this block is produced anymore and definitely didn't pay the $9K retail for it.
Anyways this is a 4 bolt head block and is priced higher than much better blocks from mentioned above.
Has billet steel caps, its been "hipped" and max bore/stroke is 4.160/4.100.
So I plan on having a 427" LS7 headed (Katech spec'd LS7 heads valves/guides, springs etc.) motor at 13:1 compression ratio. Hoping to get 705 flywheel (short travel lifters, sever duty rocker shaft, etc.).
https://www.youtube.com/watch?v=haaFtWlJ94g
I ended up getting a C5.R block from a deal that I worked out. I think this is more of a novelty these days since there are many options for the LS platform;
Dart, GM Bowtie LSX, LSR, RHS to name a few. I'm not sure this block is produced anymore and definitely didn't pay the $9K retail for it.
Anyways this is a 4 bolt head block and is priced higher than much better blocks from mentioned above.
Has billet steel caps, its been "hipped" and max bore/stroke is 4.160/4.100.
So I plan on having a 427" LS7 headed (Katech spec'd LS7 heads valves/guides, springs etc.) motor at 13:1 compression ratio. Hoping to get 705 flywheel (short travel lifters, sever duty rocker shaft, etc.).
https://www.youtube.com/watch?v=haaFtWlJ94g
Last edited by grinder11; Dec 8, 2022 at 01:19 PM.
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Match a set of C5R heads to it - and have Katech prep them since they are the expert on these motors since the C5R days which I see is already in your build plan
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Though the C5R block may not be capable of the larger displacements current aftermarket blocks are, I'd guess it's as strong, or stronger than, any other Aluminum block available. A 4.150×4.100 bore and stroke= a 444. That should snort down the track pretty good. It would also be a great candidate for FI, maybe with an LS9 blower. This would be capable of over 1,000, reliable hp. Unless you're shooting for a racing build, there's no way I'd be looking for 13:1 compression. To make 700+hp, you're looking at well over .650" lift. The LS7 heads aren't known for longevity with .600" lift! Dont ask me how I know!!! Just trying to offer suggestions. I have a 600+hp LS7 in my A4 C5, with about 11.25:1 compression. It's OK on pump gas premium, but only if coolant is under 200°F. I couldn't imagine going up almost 2 full points more. If I did, I'd have to run $10/gallon race gas. Best of luck to you......
.650" plus lift of a cam doesn't scare me off. This is a toy, but I definitely will consider your experience and inputs. LS7 heads can be properly spec'd by Katech (geometry, CHE bronze guides, Exceldyne Ti intake valves, Ferrea hollow stem exhaust and their CNC port). Or can they?? Don't want to start the LS7 head debate!
What is your coolant system that you run?
What is you complete combination?
Does your coolant system struggle to stay under 200? 200-220 is normal on my stock LS6.
My only concern about LS9 and any other blower is cylinder pressure. I know there are Vulcan Cut-Ring head gaskets and 1/2" head studs etc.. I want to avoid lifting the head. This is just going to be a hi compression-hi RPM motor that were shooting for 750 and if we can get 800 on engine dyno were totally fine with that. No intent to go 4 digit power.
Thanks
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Good Point! I thought about C5R heads and they come pretty raw. The need to build those up would be more costly than the value for what I'm trying to accomplish 750 FWHP. Factory LS7 castings done right can make some steam! I feel like the C5.R heads are more of a novelty for what I'll be doing. I don't quite have C5.R money yet. Lol
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Good Point! I thought about C5R heads and they come pretty raw. The need to build those up would be more costly than the value for what I'm trying to accomplish 750 FWHP. Factory LS7 castings done right can make some steam! I feel like the C5.R heads are more of a novelty for what I'll be doing. I don't quite have C5.R money yet. Lol
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Some rare hardware there. All you need is a block? The exact opposite of me lol
Well these blocks are stupid expensive if you buy from retailer. Mine was aborted by 2 previous owners is how I got my hands on them. Still never used. I have to finish up my falcon first (also on YouTube channel) then I'll get after this one and plan on posting progress of this build to keep the community updated. Do you have any pics of those heads you can share?
Thanks
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Niice!
Some rare hardware there. All you need is a block? The exact opposite of me lol Well these blocks are stupid expensive if you buy from retailer. Mine was aborted by 2 previous owners is how I got my hands on them. Still never used. I have to finish up my falcon first (also on YouTube channel) then I'll get after this one and plan on posting progress of this build to keep the community updated.
Do you have any pics of those heads you can share?
Thanks
Some rare hardware there. All you need is a block? The exact opposite of me lol
Well these blocks are stupid expensive if you buy from retailer. Mine was aborted by 2 previous owners is how I got my hands on them. Still never used. I have to finish up my falcon first (also on YouTube channel) then I'll get after this one and plan on posting progress of this build to keep the community updated.Do you have any pics of those heads you can share?
Thanks
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Last edited by grinder11; Dec 9, 2022 at 10:34 AM.
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
According to what I was told by a guy who tracked his C6 Z06, ITBs were worth 50hp on the engine dyno, over a ported FAST 102 intake w/102mm TB. This was 8 years ago, and was on the same, modded engine, only change was changing the intake and 102mm TB to 8 ITBs. No air filter was available for the ITB setup then, so that may account for some of the power gain.....
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Right. But the mesh doesn't filter nearly as well as a proper air filter. If I was doing what you are, all track, I'd probably remove the screens. I've used them in velocity stacks thru the years, and they aren't a good filter, but still cost some amount of flow. Of course, the screens I'm talking about have a very fine brass screen, finer than a door screen......
That said, the build is a long way off at the moment. Got to find a block first, raise my kids, and somehow find enough cash to pay Katech to put it all together...oh and a TR6060 if I can make it fit, if not, a Tremec M5 fits.
Last edited by NW-99SS; Dec 9, 2022 at 11:35 AM.
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Safety Car
Joined: Dec 2009
Posts: 4,984
Likes: 720
From: Alberta
2022 C2 of the Year Finalist - Modified
C2 of the Year Finalist - Modified 2020
Thread Starter
Pro
Joined: Mar 2018
Posts: 620
Likes: 91
From: Sacramento CA
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658
Not worried so much about drivability. I didn't mention that this will be a pump E-85 motor and I would upgrade cooling system and look into running an Aviaid 3 or 4 stage dry sump.
.650" plus lift of a cam doesn't scare me off. This is a toy, but I definitely will consider your experience and inputs. LS7 heads can be properly spec'd by Katech (geometry, CHE bronze guides, Exceldyne Ti intake valves, Ferrea hollow stem exhaust and their CNC port). Or can they?? Don't want to start the LS7 head debate!
What is your coolant system that you run?
What is you complete combination?
Does your coolant system struggle to stay under 200? 200-220 is normal on my stock LS6.
My only concern about LS9 and any other blower is cylinder pressure. I know there are Vulcan Cut-Ring head gaskets and 1/2" head studs etc.. I want to avoid lifting the head. This is just going to be a hi compression-hi RPM motor that were shooting for 750 and if we can get 800 on engine dyno were totally fine with that. No intent to go 4 digit power.
Thanks
.650" plus lift of a cam doesn't scare me off. This is a toy, but I definitely will consider your experience and inputs. LS7 heads can be properly spec'd by Katech (geometry, CHE bronze guides, Exceldyne Ti intake valves, Ferrea hollow stem exhaust and their CNC port). Or can they?? Don't want to start the LS7 head debate!
What is your coolant system that you run?
What is you complete combination?
Does your coolant system struggle to stay under 200? 200-220 is normal on my stock LS6.
My only concern about LS9 and any other blower is cylinder pressure. I know there are Vulcan Cut-Ring head gaskets and 1/2" head studs etc.. I want to avoid lifting the head. This is just going to be a hi compression-hi RPM motor that were shooting for 750 and if we can get 800 on engine dyno were totally fine with that. No intent to go 4 digit power.
Thanks
Race Director
Joined: Oct 2004
Posts: 12,859
Likes: 4,658