School me on big cubic inch LSx builds
10-17-2020, 10:12 PM
#101
Yeah you only have CID and rpm and your compression and fuel limits and that's going to mostly set how much power you make. With this long runner intake limiting RPM to under 7K I would make it 500 inches but that's not possible but as big as you can. Then fix the FUBAR valvetrain that this other shop put on that engine and you should be good. I guess the 87mm TB isn't hurting you but you should take a look at your MAP over 5000 RPM as well as it doesn't look like there's a crossover but maybe there is? With an NA piston and ring stack you can do 4.250 stroke in your sleep with that block and more. The other people giving you advice on this haven't really done many of these larger engines at all which is obvious.
Last edited by rkupon1; 10-17-2020 at 10:53 PM.
10-18-2020, 05:57 AM
#104
I had spoken with Chad Golen recently too. I know he built a 502ci(tall deck) with this intake, hyd roller, and pump gas. Made 824hp/744tq iirc. I know those numbers dont impress everyone, but remember, its not a carbed tunnel ram niether set on kill. Hyd roller on pumpgas 11.5:1 with what appears to be silver blade twin 90mm tb s. I wish I knew the cam specs on this one. I did not think to ask bcuz those cubes out of my reach.
https://youtu.be/xMehJ0QruN4
https://youtu.be/xMehJ0QruN4
The following 2 users liked this post by racer8088:
AINT SKEERED (10-18-2020), rkupon1 (10-18-2020)
10-25-2020, 08:45 AM
#105
So. I ve been doing some thinking and further research. Im looking for some opinions as well. Im thinking of ditching the short block I have currently in favor of the new build. The RHS standard deck is not of great value to me NA, at least i dont think it is. Am I wrong? Other than priority main oiling, what other features are relevant to me for a 750hp pumpgas build? Im thinking its worth more in resale value if i consider selling it with the 427ci rotating assembly put together. It appears that the RHS max bore is only 4.165. So including the cost of shipping, additional machine work, new pistons, and a stroker crank to build a 440ci. Am I putting good money after bad? Should I just call up RED and order up a Darton sleeved 5.3l, LS2, or LS7 block with all machine work done also? My engine builder buddy, who prolly will never build an engine for me again, says he s not sure about the short block. But he can defly get me top dollar for my RHS block. Or even possibly buy it from me for what I payed for it as he uses them all the time. $5000 goes along way towards a new bottom end/motor. Do any of you think its worth keeping the RHS, or not really? Im aware it has 6 bolt head provisions, piston squirter provisions, etc. But are these useful for my goals in all actuality or just novelty talk?
Also, what are your guys thoughts on how to achieve 440ci? If starting from scratch with a sleeved block, would you go 4" stroke and 4.185" bore, 4.125" stroke and 4.125" bore, or 4.1" stroke and 4.130" bore? I admit I dont know a lot about pros and cons of each. Im really curious. Im quite sure we ll be re using my MAST 285cc LS7 heads, Jesel roller rockers, and intake mani. But everything else is subject to change from here on out.
Also, what are your guys thoughts on how to achieve 440ci? If starting from scratch with a sleeved block, would you go 4" stroke and 4.185" bore, 4.125" stroke and 4.125" bore, or 4.1" stroke and 4.130" bore? I admit I dont know a lot about pros and cons of each. Im really curious. Im quite sure we ll be re using my MAST 285cc LS7 heads, Jesel roller rockers, and intake mani. But everything else is subject to change from here on out.
10-25-2020, 09:16 AM
#106
So. I ve been doing some thinking and further research. Im looking for some opinions as well. Im thinking of ditching the short block I have currently in favor of the new build. The RHS standard deck is not of great value to me NA, at least i dont think it is. Am I wrong? Other than priority main oiling, what other features are relevant to me for a 750hp pumpgas build? Im thinking its worth more in resale value if i consider selling it with the 427ci rotating assembly put together. It appears that the RHS max bore is only 4.165. So including the cost of shipping, additional machine work, new pistons, and a stroker crank to build a 440ci. Am I putting good money after bad? Should I just call up RED and order up a Darton sleeved 5.3l, LS2, or LS7 block with all machine work done also? My engine builder buddy, who prolly will never build an engine for me again, says he s not sure about the short block. But he can defly get me top dollar for my RHS block. Or even possibly buy it from me for what I payed for it as he uses them all the time. $5000 goes along way towards a new bottom end/motor. Do any of you think its worth keeping the RHS, or not really? Im aware it has 6 bolt head provisions, piston squirter provisions, etc. But are these useful for my goals in all actuality or just novelty talk?
Also, what are your guys thoughts on how to achieve 440ci? If starting from scratch with a sleeved block, would you go 4" stroke and 4.185" bore, 4.125" stroke and 4.125" bore, or 4.1" stroke and 4.130" bore? I admit I dont know a lot about pros and cons of each. Im really curious. Im quite sure we ll be re using my MAST 285cc LS7 heads, Jesel roller rockers, and intake mani. But everything else is subject to change from here on out.
Also, what are your guys thoughts on how to achieve 440ci? If starting from scratch with a sleeved block, would you go 4" stroke and 4.185" bore, 4.125" stroke and 4.125" bore, or 4.1" stroke and 4.130" bore? I admit I dont know a lot about pros and cons of each. Im really curious. Im quite sure we ll be re using my MAST 285cc LS7 heads, Jesel roller rockers, and intake mani. But everything else is subject to change from here on out.
After all the **** I went through,
I would recommend you sell the block and start new IF you can get good money for it.
If you max max it out to a 4.165, still keep the 4 inch stroke.
If you decide to use a resleeved block go ahead, I think it will be fine.
If you decide to use an aftermarket block go Dart like mine in Iron.
It has everything you need.
If you build a 440 definitely go a 4 inch stroke and 4.185 bore to keep piston speed in check and also to help reliability.
This is the general consensus I see on here from others who have given their opinions.
It's better for the bore to be bigger than the stroke.
I don't see any issues with those heads. They are are a high end product and do work.
10-25-2020, 10:05 AM
#107
Yea I wasnt sure about the stroke vs. bore philosophy. Makes sense. My engine builder feels "terrible" bout my build and lack of trust. So if he s offering to buy my RHS block full price, i ll gladly take it. He s not interested in it as a built short block, so I may try to sell it like that first before separating it all and selling it off piece by piece. I am NOT interested in anything IRON unless its free. Call me spoiled or whatever...
10-25-2020, 10:22 AM
#108
Yea I wasnt sure about the stroke vs. bore philosophy. Makes sense. My engine builder feels "terrible" bout my build and lack of trust. So if he s offering to buy my RHS block full price, i ll gladly take it. He s not interested in it as a built short block, so I may try to sell it like that first before separating it all and selling it off piece by piece. I am NOT interested in anything IRON unless its free. Call me spoiled or whatever...
You thumb your nose at iron. Haha
If it needs to be aluminium, go a sleeved block or a Dart aluminium if you want to spend the big $.
The Dart aluminium also only go out to a 4.165 bore.
10-25-2020, 10:41 AM
#109
The Dart aluminum is out for the same reasons my RHS block is out! Lol, unless theres some decent reasoning to keep it and make up for it in additional stroke. Just seems by the time I factor in shipping both ways and additional machine work, id be better off and ahead to just buy a new purpose built and sleeved block. Assuming I can get top dollar for my RHS block. Itd be even nicer if I could sell it with the rotating assembly in it too. Make way for new. #MORECUBESLIFE
10-25-2020, 01:07 PM
#112
Yup, only downside I see is 4.185 means your at final bore and next rebuild means a new sleeve, lol. Which IIRC, the Darton MIDs can be changed out at a single time. But what you gain in valve unshrouding etc seems to be better. I know this is not a build to get technical over. Im just trying to learn something and think it thru. Last build, i just said yes to everything, and here we are...
Last edited by rkupon1; 10-25-2020 at 08:09 PM.
10-25-2020, 01:17 PM
#113
Yup, only downside I see is 4.185 means your at final bore and next rebuild means a new sleeve, lol. Which IIRC, the Darton MIDs can be changed out at a single time. But what you gain in valve unshrouding etc seems to be better. I know this is ot a build to get technical over. Im just trying to learn something and think it thru. Last build, i just said yes to everything, and here we are...
This will give me 5 rebuilds with custom pistons 5 thousands larger with the 6th rebuild will be with a shelf 4.185.
The pistons I have now were custom as CP and JE do not have a 4.155 for a 15 degree head. Only for the 12 degree ls7 head.
Only took a week for them to make them.
Maybe start off with a custom 4.170 bore piston so you have 3 more rebuilds ahead of you.
10-25-2020, 10:33 PM
#114
Apologies if you have stated this elsewhere, I don't recall reading it.
I know you are putting this into your Pro-Touring car, but what do you plan to do with the car? Autocross? Track Days? Street Driving only? Drag Racing?
I personally think you are better off selling the current block and having RED sleeve a block. There are others who can also do it (Texas Speed comes to mind, I know others as well). The last time I spoke with Steve at RED, he didn't source the blocks, so you have to buy one yourself. That was 3+ years ago. A source like TSP may be easier, but you would likely have to buy a new block from them. Basically have to balance the costs here (block cost, shipping costs, sleeve costs, etc...). i initially used a 5.3L block as they are supposedly stronger. When that one was damaged, it was replaced with an LS9 or LSA block (I can't recall which, but it's the one with larger head bolts) because it's one I could easily get which needed a sleeve. In hindsight, for my goals, I didn't need either and an LS2/3/7 block would have been just fine for me.
For a PT car, the aluminum block is definitely a benefit. And unless you are going to beat on the engine hard doing track days, the priority main oiling really isn't necessary. Is it nice to have? Sure. But plenty of SBE LS7's and others are being beaten on and surviving just fine. Without nitrous or FI, stronger blocks aren't needed. I feel similarly about the other 'novelty' items you mentioned.
I built a 434ci LS7 based engine. I just didn't have a reason to bore it to a 440, so I stuck with the 4.155" bore and 4" stroke. With a less than optimal induction, I was around 720 HP on the engine dyno in the low 7k RPM range. I very much liked the combination when it was all done.
Best of luck with your decision...
I know you are putting this into your Pro-Touring car, but what do you plan to do with the car? Autocross? Track Days? Street Driving only? Drag Racing?
I personally think you are better off selling the current block and having RED sleeve a block. There are others who can also do it (Texas Speed comes to mind, I know others as well). The last time I spoke with Steve at RED, he didn't source the blocks, so you have to buy one yourself. That was 3+ years ago. A source like TSP may be easier, but you would likely have to buy a new block from them. Basically have to balance the costs here (block cost, shipping costs, sleeve costs, etc...). i initially used a 5.3L block as they are supposedly stronger. When that one was damaged, it was replaced with an LS9 or LSA block (I can't recall which, but it's the one with larger head bolts) because it's one I could easily get which needed a sleeve. In hindsight, for my goals, I didn't need either and an LS2/3/7 block would have been just fine for me.
For a PT car, the aluminum block is definitely a benefit. And unless you are going to beat on the engine hard doing track days, the priority main oiling really isn't necessary. Is it nice to have? Sure. But plenty of SBE LS7's and others are being beaten on and surviving just fine. Without nitrous or FI, stronger blocks aren't needed. I feel similarly about the other 'novelty' items you mentioned.
I built a 434ci LS7 based engine. I just didn't have a reason to bore it to a 440, so I stuck with the 4.155" bore and 4" stroke. With a less than optimal induction, I was around 720 HP on the engine dyno in the low 7k RPM range. I very much liked the combination when it was all done.
Best of luck with your decision...
The following users liked this post:
NAVYBLUE210 (10-26-2020)
10-26-2020, 07:41 AM
#115
Launch refer Rup to the Dart 🎯 Tall block it has the 4.220 bore that's more preferred....There's only a few, like 1 or 2 with a 4.220 Lsx . Dart is seen more since it shorter time being out.
Launch why didn't you give these guys something to read.....in the upper Room heads thread.
Launch why didn't you give these guys something to read.....in the upper Room heads thread.
10-26-2020, 08:26 AM
#117
10-26-2020, 08:47 AM
#118
LS *Next*Iron or aluminum block is the one that's
4.220 capable,So no 1 gets confused. SHP block is 4.185 recommended. A little heat didn't hurt anyone B. Thermostat choice? Weight vs Cost is what it boils down to typically B. I'm Wanting to see what Block is used for this nitrous build 4.30 et wanted🤔 @ 2300lbs.
4.220 capable,So no 1 gets confused. SHP block is 4.185 recommended. A little heat didn't hurt anyone B. Thermostat choice? Weight vs Cost is what it boils down to typically B. I'm Wanting to see what Block is used for this nitrous build 4.30 et wanted🤔 @ 2300lbs.
Last edited by Corona; 10-26-2020 at 08:53 AM.