Wicked94Z

iTrader: (26)

I'm running 25psi hot idle... not running much spring pressure though

LT1STROKER

iTrader: (3)

no spray at all in my future!! I know my exhaust flow number seem good but i also know that being pflowed with pipe, generally exaggerates the numbers and these heads were flowed with a 2" stack on them, so i dont really use those numbers as true numbers for what my car would see; even with that being said, i must admit i am obviously still thinking in the old tradidtional sbc train of though with as much split, i am going to play with less split and see what comes! Good heads up, thanks

ok here is the thing i found, with the 240 duration lobe the 108 seems to be a better match for this motor, as it lets the motor pull evenly past peak power with only a minimal hp drop from peak, where as with the 106, or 104, it gains about 6 ft lbs of tq under the curve, for a tradeoff of the motor dropping off more after peak power. Now the 244 lobe does like the 4-6 degee advanced ic.

i have never spoken directly with bill, when matt put me on hold he made mention of having to discuss a few things about my setup with a bill, and i inquired to find out that he was speaking with a guy of that name,

bowtienut

iTrader: (1)

Same word of caution: be careful of the simulation programs; they always underestimate the rev range with the LT1 manifold. On a cam like that, the car will pull better 60' times, better ET's, and drive better with a 106 ICL than with a later ICL. In fact, I can think of no instance where you would want later than 107 in any Gen1 or Gen2 SBC. I know it's really all about the IVC event, but unless you're running a crazy asymmetric lobe, it's just not gonna happen.
Focusing on that high rpm hp takes away from the overall package performance. You will only notice that hp beyond the peak on the dyno.

Puck

iTrader: (17)

Depends on the whole package. I would much rather have a handful less tq but hold peak rpms longer then a couple more tq and hp dropping off sharply after it peaks. Makes it much easier to spec gears and a stall that can keep you in your desired rpm range.

Best advice is still to not put too much faith in simulations and talk to the pros that have been there before like LE and Phil.

toby

iTrader: (1)

that engine will definetly like a tighter lsa around 106 or 105. don't overdue the duration and it will drive great.

LT1STROKER

iTrader: (3)

are you meaning a lsa of 106 or 105 or are you meaning a intake centerline of 106 or 105. I cant see how this thing is gonna be much of a driver with a 105 lsa. Also with that tight of lsa and not much duration, would i not have to be concerned with my compression at 12.3:1 reversed cooled or not?
I have seen used lsa that tight but on mostly strip cars, where wide open performance is of most inportance.
Thanks for your reply,
if nothing else this thread may help someone else with cam selection as well.

toby

iTrader: (1)

you will be fine with 12.3:1 in a lt1. a lsa of 105 and an ic of 101 will make the most power. a duration in the low 240's should not be too big. this is a 414ci isn't it?

Wicked94Z

iTrader: (26)

I found the lobes you're looking at... I think you'd be a pioneer running that intense of a lobe in a HR application what did comp say in regards to valve springs for those lobes? What pushrods are you planning on running?

bowtienut

iTrader: (1)

Yep......thus my earlier comment that he REALLY should be going straight for a solid roller setup shooting for his hp numbers. Money says the solid would be more dependable in a driver than trying to do that with hydraulic.
And toby, I have to disagree with your suggestions regarding LSA and ICL. Unless you're picking the wrong lobes to start with, staying with 108 LSA and 105-106 ICL is going to give you a better power curve for a driver Plus, assuming he's planning on running pump gas, that ICL would be a problem.
LT1Stroker, you really will spend less money and maintenance on a solid roller when trying to run this much cam. Please reconsider

toby

iTrader: (1)

actually aggressive sr lobes make for great high rpm hydraulic lobes because they are less aggressive on and off the base circle due to the lash ramps.

Puck

iTrader: (17)

Maybe I'm just too exhausted to think from lack of sleep, but solid roller lobes are actually more aggressive off the base since they have a faster ramp rate then an hr lobe, which is what makes their effective duration shorter.

This is why a solid roller behaves like a hyd roller of around 10* less duration.

toby

iTrader: (1)

you're not taking into account the lash ramps. they are not included in the advertised duration. if they were there would be much more adv. duration. the advertised duration is usually .020 of the base circle.

LT1STROKER

iTrader: (3)

Yes this is a 414 LT1, but I believe staying with low 240s duration with 12.3:1 and a LSA of 105 and IC of 101 will definitely create problems with pump gas. I may be way off mark but it seems that that will definitely throw the dynamic CR up, and require the use of something other than pump gasoline. Also I would imagine that with this type of LSA I would need a good bit more duration to make something like this work in my application.

They are pretty aggresive, but I have been told that this lobe would be compatible. Comp said that if I am to use their short travel lifters 15853-16, then I would need to run springs that have about 150-160# seat, and about 425# open max because of the lifters, along with their tool stel or titaanium retainers. He gave me part numbers, but I cant put my hands on them right now, because both of them suggest that the Lunati lifter would probably work better for this situation, and controlling valvetrain, as well as giving me the benefit of having use of my current springs, and having more spring preassure closed and opened. How about that, a comp tech saying that another competitors part may better fitted to an application. I also haven't figured out the pushrods as length will have to be determined first, once I determine cam spec and get here to mock up and see what length is needed. I planned to use either a set of Manley or comp HiTech pushrods.

Ok here is the thing, before speaking with Lunati about their race type Hyd roller lifters, this was going to be a solid roller motor, mainly because of ease, and I was going to just deal with the lash etc, periodically. But upon speaking to Lunati, they expressed that these lifters were designed for this reason originally anyway, and it will cut out the lashing etc, type maintenance of a solid roller lifter, and also the worry of lifter breakage from the abuse of a lashed solid roller cam on the street. So hence I figured I would have the best of both worlds I know that I will come out a little cheaper based on lifter price cause these lunati pieces are not cheap, but maybe it was worth it I figured.

Hence my statement earlier ^^^^^^^^

You definitely have me reconsidering, because it will save me money, but there is a definite advantage of stealth if I can have a cam that sound like a hyd roller (without lash), and still have benefits of the more aggressiv lobes. There are 2 LS guys in my area that dont give us LT guys a bit of respect, and I am trying to put together what may be a wolf in sheeps clothes, (sheep with red eyes and a pair of horns of course :-)Thats all I have even taken the detail to have my 42 pound injectors put in a non green top housing

Thanks guys foryour Input This is sooo much help to me you will never know.

LT1STROKER

iTrader: (3)

There may be some truth to all of this lash ramp talk, because I do remember Matt talking about these cams have a gentler lash rampwhich allows them to be run in solid form with only .010 lash with out a problem. That was the first time I had heard of this, I had a totally different idea of how the lashh worked before, this discussion, and am not completely cleared up on this now, but I do know that cam companies oviously build different ramps to allow the lash to be tight or loose, and it is considered maybe a different entityfrom the actual ramp rate after lash. He said it is because of the lash ramp on this cam, that it is not so violent on the Hyd roller lifters, but you would want a shorter travel lifter designed to handle more shock than your standard stock gm lifters. From what i took from the discussion of this is that you would not want a solid roller cam that is designed with a lot of lash ie .022 and greater running as a hyd due to the lash ramp being more aggressive, therefore needing more time space before the actual acceleration of the lifter begans; would keep the lifter plunger in the hyd always bottoming out, from the aggressiveness, thus lifter failure. if you look at a comp hyd roller its seat duration is done at 0.006, thus actual duration begans at this point maybe, the area before 0.006 would be considered the lash ramp, but if you look at their solid rollers they are rated at 0.010-0.028, meaning more aggresive lash ramps, needing more dampening before you get to actual duration of cam. Those cams of less than 0.020 lash generally are able to be ran as a hyd, if the right springs can be found to keep valvetrain stable based on intended RPM.
Do not quote me on any of this explanation, as this is how I interpreted it from the discussion with Comp Cams; I probed pretty good to get a pretty good explanation from the two as some things I asked he had to refer to the Bill guy for answers to dome of these questions.
Hope this helps, and not hurts anyone, as I may waaaaaaaay out in left field!

LT1STROKER

iTrader: (3)

Hey I actually like this Idea it seems to work well, and even at a 108 +4 it was only down (about 18/23 hp/tq respectively) slightly compared to a 244/248 using the lobes I speak of at 108 +4, and I am to probably guess that is only because of acceleration rate, and a little additional lift, but I bet this would be easier on parts, ran as a hyd, or were you intent on these number for use as a solid application? Is SP the family of lobes these lobes come from?
What do you think of the lobes I am talking about, based on my conversation with Comp ^^^^^^^^ ; would you shy away or give it a try, I don't mind being a pioneer , however I do mind being a dummy

LT1STROKER

iTrader: (3)

Here is some insight, simply for those who want to know, of where I got my build idea. T&L built 2 of these motors for Chevelle magazine and for Popular Hot Rodding. The one in the CHevelle mag was done based on hyd roller using Xtreme energy lobes single pattern cam 288/288 236/236 and as toby said they used a 105 LSA. However they also only had 10:1 CR using 75cc AFR 195 heads.THey used a 1.65 rocker, and got .575 lift. This motor made 549hp and 530tq and peak power was made at 6250 with an Edelbrock RPM .
Here is the link to this build : http://www.tandlengines.com/article_...%20Article.pdf
The other practically the same thing accept they used the AFR 210, a bit more compression at 10.5:1 and a solid roller, using the Xtreme energy lobes, still single pattern 280/280 242/242 and again with a 1.65 rocker .602 /.602 lift, still on a 105 LSA.
THey did more intake and carb testing with this setup, from a RPM Air Gap, to a Super Victor single plane and then to a Dominator Super Victor. This motor made its best with the single plane Dominator at @ 595hp , 4150 style VIctor made 578 or so hp both around 62-6300.
Here is that link : http://www.tandlengines.com/article_.../PHR_May09.pdf

This is just for those interested!
i am hoping to better those numbers with the LT1 since it allows me more compression, and I have use of a just slightly better head, by flow compare. Both of these setups made mention of having a near lope free idle at 850, and both were designed to made peak power by the 6000 range. and both used the 105 ICL. Who knows??

toby

iTrader: (1)

those 2 engines do illustrate what i was trying to say. i think you would get good results using those sp lobes wicked94z suggested. what lsa you use depends on what is more important to you. if you want more power use 105. if driveability, ease of tuning, and gas mileage is more important use 108 or wider.

Puck

iTrader: (17)

Interesting articles.

I also plan on 600hp with a hydraulic roller, but it is not an easy or cheap task. I completely gave up with simulators after numerous nights of testing, and will just be sending my head flow sheet to Llyod to spec me my own HR and recommend me the best springs to use with it. It is important to never cut corners on a build this aggressive.

My specs are 12.5:1 CR, half filled 4-bolt splayed 383, Super victor, ported AFRs(330cfms), 1.7 shaft mount rockers, EFI connection LSX computer conversion, and whatever cam and springs LE tells me to use. Of course also all the supporting mods you would expect - EWP, 42# SVOs, racetronix pump + hotwire setup, etc. I am still looking on whether I will run LS7 lifters or bite the bullet and get the morels for piece of mind. Even if they are not worth any power, they are machined bodies so they are stronger and more reliable in high hp/rpm builds the OEM style cast lifters...

LT1STROKER

iTrader: (3)

Well I have to put drivability slightly above the power because I do plan to drive this car probably 150 miles a week. This may have been why LE speced his cam at 112, who knows. He made the statement that it will keep the intake from filling with exhaust gasses from overlap. To say the least I want to drive the car, which may be the only reason I step back to the 110, rather than the 108 or lesser.

Wicked94Z

iTrader: (26)

you have 414 cubes man... you WANT overlap with that crazy 4" stroke to fill those cylinders and make power! more stroke likes tighter centers.........