I agree, I'm not a machinist nor do I understand all the techno stuff, But I examine and critique stuff and compare. The LS series shares a lot of design with the 350 Buick, no big advantage to the LS there. The LS heads are where they blow away the Buick, everybody says "the power is in the heads" ITS TRUE! When the aluminum heads come to market for the Buick 350, things will change
Right on! Sounds like some serious SBB fun. Glad to hear all is well. Roast any tires lately? Good times...
If people were getting the iron heads in the 260-290 cfm range it would already be an absolute game changer, but not many shops want to lose money porting iron heads.
I have a set of Gessler Level 3 heads going on an engine soon. The flow sheets for those maxed out at 250 @ 0.600 lift. This was inline but a little below the quoted numbers for a set Jim Burek heads as well as a set of Tri-shield Performance heads. Hoping to see some dyno results soon.
Just want to say I appreciate the commentary you all have given. The power is definitely in the heads. Tho you can spray or boost an ls in stock form and it'll take a beating like the SBB engine Fox has been running. Both provide a solid platform which is another reason for questioning which to build. Being able to drive around town without issues is of concern. Doesn't have to be the best but is necessary. Lol.
Too bad Mike Phillips is semi retired. He did get regularly 245 cfm from 350 heads. But a 1.94 valve. Maybe that .020 helps .
General comment on choosing valve sizes... Sometimes the valve is selected based on what the VJ throat size is going to be for reasons of determining the torque peak rpm or how the engine might lend itself to street driving, especially if the throat is the minimum CSA, rather than peak cfm #'s. There are times that the hp goal is likely met or exceeded by cfm and a need to keep peak torque at a lower rpm, other than restricting it with shorter cam events. A 245 cfm head passing a 1.940" valve still has 500 hp potential and could keep a lower peak torque rpm than going to a bigger valve (if the MCSA is the throat). There are times in which the bigger valves having a larger curtain area and better low lift flow could contribute to an over cam situation, losing low end response. Retarding the cam when too big is a poor way to attempt to bring some of the response back by maintaining the pressure differential between the cylinder and intake under that circumstance. As far as driveability...I'm not seeing any advantage to the LS other than using plug and play electronics, which becomes more equal when you use the EFI. The Buick is still a formidable engine, with any loss of driveability being the responsibility of the builder, tuner, and component chooser. Not the machine's fault. This still comes back to the people or knowledge you use over the machine type. How does that fit into your 'budget'?
Care to elaborate on what areas of the SBB head you would focus on and why when porting? See the ls 6.2 in mind makes said hp in stock form. Tune alone would boost those#s. Cam headers and tune again and wam 460- 480hp @the crank with good street manors and who doesn't like the sound of a good lope? The factory hp #s are cool but if I'm gonna do anything I want to go big. Not really budget minded here it's more So what makes more sense to build to achieve a desired hp and tq. Hence the question what would it take. After knowing what it would take and figuring the $vs$ to build said engines and weighing options a decision cam be made Anyhoo I guess there's always the BBB but that's another thread.
https://streettechmag.com/2015/03/23/porting/ Going to need big valves. It's going take some work to achieve what you desire from the 350 . Going stroker would really be the way to go.
No. My normal response to that in a face to face conversation would entail discussing your budget and goals, but that's not what I'm here for. Research the forum, plenty of free info abound. I think there's a more detailed head porting article scanned in from somewhere. Love these circular conversations, now we are talking about 460-480hp. Dollar for dollar or using talent to help you, the 455's and strokers are looking better every minute. Confused as to why people think LS engines have any superiority. People's goals, aftermarket support, and budgets are different these days. There's always been skilled people able to get good flow from heads, it's been more of a trend lately to expect streetability with reliability at the same time. B 455's, Chevy 454's, Cad 500's and many others have had good head flow potential from the beginning...and can exceed this thread's hp, torque and mileage expectations by a healthy margin. It just wasn't as popular 25 years ago to try. Nothing new but the target market demographics of the expected builds.
The engines have always had the capability, the general public is catching on to the fact we can have our cake and eat it too. One big problem is the labor cost, especially porting heads. One might think $1500-2500 for fully ported heads is good for the porter these days...not when some heads take 80-100hrs to max out and the shop's burden rate is $100/hr. You pretty much have to build a complete high end engine to hide or spread the losses around. This thread is like asking if the sub 4 minute mile was ever possible after Roger Bannister did it. Not many believed it to be possible. It isn't fuel injection, overdrive or a special new design engine, it's been done long ago.
I think your missing my point about going FI. sure a correctly tuned carbed engine can perform the same. Thing is I'd like to make use of FI for personal reasons. No worries man. Thank you for your time.
Misunderstanding that again, I support whatever reasons you have for it's choice. I was hoping you wouldn't single out that one tiny aspect and overlook the meat and potatoes. The point of that garnishment was to illustrate that there's no magic to the LS that any other engine doesn't already possess. Thank you for your conversation.
If you are going to search eBay for nascar take out rods to do a stroker build you want to look for at least 6.300" to no more than 6.450" long rods. Any shorter and the piston would have to be heavier than it needs to be and much longer and there would be perhaps to much cam interference and cam clearancing needed or the need for a small base circle cam and or both. You also want to look for the take out rods that are preferably the ones that are .900" thick on the big end so they can be narrowed with the proper offset. For the max stroking of .140" to get to a 3.990" stroke is wanted then the rods with the 1.976" or 2.008" housing bore is what you need with the smaller bore size giving a bit more cam clearance because both of those sizes have the 1.850" diameter bearings available for them. If you find rods you like with the 2.015" housing bore, those only have bearings available for the 1.888" rod journal size and possibly a couple of under sizes as well because they are what is used in some Honda engines.
Well usually I try to respond to all of what one says. Your right about the ls. It just makes power easy.
Just thought about something. Since I'd be going with different rods and crank work. How would i figure out the new pistons size? How far in the hole should they end up?
