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Launch, that is a nice setup! I agree with you on the stroke. Keep it 3.622. I personally have always preferred to keep a motor over square. If you put a 4 in stroke in there you will make the same power but with 30-40 more torque. If you do stroke, sleeve it and punch it out to 4150 or so. My opinion. Honestly, I wish Chevy had not stuck with 4.4 bore spacing and had decided to go 4.5. Woulda made the block a half inch longer and wider. But think of the options and what that would have done for the platform.
Your heads sound like C5R heads. They were a really small ls7 style port but still flowed amaze *****. If the top ten fastest NA lost in the racing section is still valid, check out how many are C5R heads. Maybe that will be worth some motorvation?
I see what you did there Thanks man. I agree on the stroke versus bore, and the bigger bore space.
Imagine a 4.300 bore / 4.00 stroke aluminum LSX with bigger valve ls7 heads
These trick ls7 heads i have are just going to waste sitting in their boxes doing nothing. They probably are a bit more C5R like, versus oem vette ls7 heads. Except these with smaller valves.. only 2.10 / 1.55. And these have tiny 49.5cc chambers also, makes it more difficult with the shelf pistons. All of the flat tops come in just a bit too much dynamic CR with my camshaft for pump unleaded, the dished not enough. Only DSS brand pistons have a dished piston that ends up in the middle, high 11 static CR from memory, in the mid 8's somewhere dynamic, but not sure i trust them over Wiseco. A local seller here has some old stock Wiseco forged flat tops, that are perfect, but will end up around 12.6 static / low 9's dynamic. I'd have to then run e85 and upgrade all my fuel system also. So i still have to decide on that.
I see what you did there Thanks man. I agree on the stroke versus bore, and the bigger bore space. Imagine a 4.300 bore / 4.00 stroke aluminum LSX with bigger valve ls7 heads
Oh I have... 2.4" intake, 1.7" exhaust, raised runner 285cc square ports, 11 degree valve angle, extra long valve stems, 2" installed height. Time to update the $50K build thread....
These trick ls7 heads i have are just going to waste sitting in their boxes doing nothing. They probably are a bit more C5R like, versus oem vette ls7 heads. Except these with smaller valves.. only 2.10 / 1.55. And these have tiny 49.5cc chambers also, makes it more difficult with the shelf pistons. All of the flat tops come in just a bit too much dynamic CR with my camshaft for pump unleaded, the dished not enough. Only DSS brand pistons have a dished piston that ends up in the middle, high 11 static CR from memory, in the mid 8's somewhere dynamic, but not sure i trust them over Wiseco. A local seller here has some old stock Wiseco forged flat tops, that are perfect, but will end up around 12.6 static / low 9's dynamic. I'd have to then run e85 and upgrade all my fuel system also. So i still have to decide on that.
If you build it to 12.6, and this is entirely up to you if this experiment would be worth it, you might cam swap for cheaper than all the other stuff. Like I'm at 12.6/8.6 if I run the IVC out to 55 degrees with a 53 degree ramp rate on the VE calculator. But really only if it would go into a big inch build, or else you'd probably hate it.
If you build it to 12.6, and this is entirely up to you if this experiment would be worth it, you might cam swap for cheaper than all the other stuff. Like I'm at 12.6/8.6 if I run the IVC out to 55 degrees with a 53 degree ramp rate on the VE calculator. But really only if it would go into a big inch build, or else you'd probably hate it.
I have thought about that. I will have to calculate what a cam a bit larger than what i have will end up doing to the DCR. The cam i have is already 30 degrees or so overlap. Like you said as i'm keeping it a stock stroke 364ci, i don't really want to go too huge on the cam. The 24hr daytona nascar engines that ran these ls7 heads i have, they were little 332 cubers and made dead on 600hp with intake restrictors and mid 7k rpm limit, all with just 240/240 cams around 600 lift. So i think the heads must work really well, and hopefully won't need a huge camshaft.
If i can make an honest 650hp flywheel, n/a with a CID intake, and then further concentrate on the rest of the car, suspension and remove more weight, it'll be enough for what i want. Here's a bit of basic info on those nascar engines for anyone interested or curious.. i have an entire PDF saved that goes into very specific details about the engines
Also just to mention, my pair of heads were run on a 4.075 bore engine, but they do fit on 4.000 bore as they previously ran the same heads on 3.900 bore engines and they didn't increase the valve size or alter anything on the heads, other than they opened up the chambers a little...
I have thought about that. I will have to calculate what a cam a bit larger than what i have will end up doing to the DCR. The cam i have is already 30 degrees or so overlap. Like you said as i'm keeping it a stock stroke 364ci, i don't really want to go too huge on the cam. The 24hr daytona nascar engines that ran these ls7 heads i have, they were little 332 cubers and made dead on 600hp with intake restrictors and mid 7k rpm limit, all with just 240/240 cams around 600 lift. So i think the heads must work really well, and hopefully won't need a huge camshaft.
If i can make an honest 650hp flywheel, n/a with a CID intake, and then further concentrate on the rest of the car, suspension and remove more weight, it'll be enough for what i want. Here's a bit of basic info on those nascar engines for anyone interested or curious.. i have an entire PDF saved that goes into very specific details about the engines
Also just to mention, my pair of heads were run on a 4.075 bore engine, but they do fit on 4.000 bore as they previously ran the same heads on 3.900 bore engines and they didn't increase the valve size or alter anything on the heads, other than they opened up the chambers a little...
I have thought about that. I will have to calculate what a cam a bit larger than what i have will end up doing to the DCR. The cam i have is already 30 degrees or so overlap. Like you said as i'm keeping it a stock stroke 364ci, i don't really want to go too huge on the cam. The 24hr daytona nascar engines that ran these ls7 heads i have, they were little 332 cubers and made dead on 600hp with intake restrictors and mid 7k rpm limit, all with just 240/240 cams around 600 lift. So i think the heads must work really well, and hopefully won't need a huge camshaft.
If i can make an honest 650hp flywheel, n/a with a CID intake, and then further concentrate on the rest of the car, suspension and remove more weight, it'll be enough for what i want. Here's a bit of basic info on those nascar engines for anyone interested or curious.. i have an entire PDF saved that goes into very specific details about the engines
(images deleted to reduce post length)
Also just to mention, my pair of heads were run on a 4.075 bore engine, but they do fit on 4.000 bore as they previously ran the same heads on 3.900 bore engines and they didn't increase the valve size or alter anything on the heads, other than they opened up the chambers a little...
You are actually the third person to send me some of that info. I do not know enough about it, so it's very intriguing reading. My gut on it is that the ports are small due to the shorter stroke - they need to develop airspeed, and possibly even sacrifice flow to get the airspeed up. It's kind of up to you, but I'd be interested in what the larger LS3 valve could do for those things - particularly the .200-.400 lift range. At the same time, GM probably studied all that stuff and spent gazillions on it, so what do I know?
Side story, but funny - I was working with an international team on developing and testing new corporate software, and all the numbers had very high digit counts to accommodate future estimated high record counts. Numbers like 500000000000001324. So, when we were brought in to test features, we would say things like, "5 gazillion and 1324" to describe which record to test. One of the international members came up to me rather sheepishly, obviously embarrassed to be asking the question, "How many zeroes is in a gazillion?". So I explained the joke (I was nice).
Anyway, back to your post... I do think you're right that you hit a point where the car is more important than the power. Hio wasn't wrong about that in the other thread. One thing to consider is the overall displacement. Those motors had a really short stroke. Now I'm not going to sit here and say that the short stroke and being way oversquare is why it revved per se, but it is well known that if you move the same heads and cam to a bigger motor, you bring that power peak down some. The heads and cam become mathematically smaller. So you'll be taking a 330 CI top end that revved like crazy and dropping it onto a 6.0. In that sense, if you still want the rpm, you might want to add degrees to the cam. for example, a 244/252-114+4 will get you 8.7 dcr with 12.6 scr, and will want to peak around 7200-7500 rpm. Would be a good match for a CID. just make sure the valvetrain is set up for it.
Spent yesterday evening clearancing some last minute odds and ends. Got the front cover installed and aligned. I have two minor things left to do and the motor can go in!
Spent yesterday evening clearancing some last minute odds and ends. Got the front cover installed and aligned. I have two minor things left to do and the motor can go in!
no rushing but we are waiting for this thing to fire up sir😁
no rushing but we are waiting for this thing to fire up sir😁
LOL, I'm not rushing, but I'm moving along. The majority of the detail work is done, so I can start to plow through. I've got help already scheduled for the install!!
LOL, I'm not rushing, but I'm moving along. The majority of the detail work is done, so I can start to plow through. I've got help already scheduled for the install!!
Yup - way back on post 1036, lol. Seems like forever ago now. I rotated the engine 16 times and verified every single cup as they moved. The holes in these heads are massive. i think I could have run 7/16.
LOL, I'm not rushing, but I'm moving along. The majority of the detail work is done, so I can start to plow through. I've got help already scheduled for the install!!
LazerLemon ftw. He's traveling the country helping the crew button things up
I do think you're right that you hit a point where the car is more important than the power. Hio wasn't wrong about that in the other thread. One thing to consider is the overall displacement. Those motors had a really short stroke. Now I'm not going to sit here and say that the short stroke and being way oversquare is why it revved per se, but it is well known that if you move the same heads and cam to a bigger motor, you bring that power peak down some. The heads and cam become mathematically smaller. So you'll be taking a 330 CI top end that revved like crazy and dropping it onto a 6.0. In that sense, if you still want the rpm, you might want to add degrees to the cam. for example, a 244/252-114+4 will get you 8.7 dcr with 12.6 scr, and will want to peak around 7200-7500 rpm. Would be a good match for a CID. just make sure the valvetrain is set up for it.
I think i need to listen to you on this and just get another cam that will bring down my dcr to an acceptable level so i can stay with pump premium unleaded. The wiseco flat top pistons that are here in stock give me around 12.6 scr, maybe even as high as 12.7. But those wisecos are now going to be too heavy for the balance. I weighed my lentz rods and they are 749 grams each with bolts (no bearings)... they don't look it, but they are heavier than i thought they were going to be... approx 109 grams each more, than stock gen4 rods.
So i have no choice but to go with JE flat top pistons instead which are the lightest i can find, to not need to add weight to the crank. With the JE's, the total piston/pin/rod weight will come in almost exact same as a sbe gen4 rod engine. And they have a few more cc's in the valve reliefs than the wisecos, so scr with the JE's comes to 12.4 .. so i will do more calc's on the dcr.
Thanks man. I agree on the stroke versus bore, and the bigger bore space.
