speedtigger

iTrader: (16)

I would not put too much stock in those engine programs when it comes to camshaft iteration. They are typically pretty unreliable and often daft.

Patron

You may be right. I gave Comp cams and Westech dyno the benifit of a doubt for a cam swap and trying to get mid 10"s with a 150 hot shot on a 383.

Speed you being the cam guy you are what type of cam am I asking or looking at. It has a more plateau or flatter type lobe to keep the valve open longer to have more area under the curve to maximize airflow. I've found this one lobe I've never seen before. It's under Comp cams DIX cam profile: The DIX series is similar to the RX but with substantially more area under the curve.. I don't know which has more area under the curve , vs cam profiles such as the Comp UBR or HXL line of cams. I'll call tomorrow hoping you could save me the time. Didn't mean to get off base just I'd like to know which has more of what I'm looking for.

KW Baraka

iTrader: (7)

Wow.....talk about jumping off the deep end.

Who mentioned anything about reving to 8500 RPMs or .800" lift?

Where did that come from?

KW

Patron

KW we did see what happens @ 6k and it's about even. Why not ask for 7000 to 8k (also maximize the high flow of the big bore heads) we have the low level 6k rpm limit. The bigger bore should do so much better as they have said which didn't go as one may have thought. Why not ask to see? The bigger bore does this and that with around the same CID. The kittty 6k rpm is known so let's go on the deeper end of the pool.... to see what happens.(Oh it rev's well let's See) Just for the sake of RPM to see and know. I know for a fact no one here who would buy a cam with that much duration and lift. Just a cost less test to see what happens. The cam lobes asked about above are just from reading and that was my own personal ?

Patron

I'd like to see how good money was wasted on a more expensive build to make and what a junkyard stroker does in its sleep for less. We know what happened at 6k.

5.7stroker

iTrader: (36)

But what if the application is twin turbo street car and not NA? How do you view the smaller cubes then? Is it still "why go TT 388 when you can go TT 427 since you are spending money on an aftermarket block"?

At what point is too much too much? I ask because I'm in conversations with engine builders on how big to go.

4.125" bore x 3.622" stroke 388 with twin 366's is all that is needed to run 8.60's at the track while being more than enough power on the street.

Would a TT 427 not be overkill on the street? I realize this is a non forced induction discussion, but curious how this thought applies when discussing forced induction setups as I know next to nothing about turbo applications.

Darth_V8r

iTrader: (4)

I read this and your post in the 427 vs 427 thread. Given that you want lower low-rpm torque, i'd tell you to go 388. And honestly, I'd even tell you to think about running a single larger turbo to delay the spooling for your street use - IF you're thinking to de-torque it for street use. Or maybe instead of twin turbo, run more like a two stage.

Yes, I think a twin turbo 427 might be hard to control on the street, but there again, a single larger turbo would delay the spooling and help with lower rpm control. Might even make MORE power up top vs the twins.

Switching focus to the top end power, I do think that anything that makes more power NA will make even morER power FI. Sort of like how ported heads benefit FI even more than they benefit NA. The rules don't change, just the pressure difference between the intake manifold and the cylinder.

Patron

Pretty much what Darth said check your in box.Too much Down low Tq is not needed or wanted you'll have more than enough with FI. Pretty sure John would have said or thinking the same thing as above. Besides what he told you over the phone.

pantera_efi

iTrader: (1)

Hi ALL, yes the remarks in the above stated tech are true. (COMPLETELY)
Example: "speedtrigger" = True with respect to the BASE numbers, NOT a Lobe File, that was specified !
EAP is ALLOWED to input the lobe files I use for Crower Cams orders, the Andrews file.
The Cam Doctor lobe file is also allowed input.
The use of these produce MUCH greater accuracy.

The heads are of great concern with respected flow numbers ALLOWED as input.

These first two items, if provided, are MAJOR factors in an EAP report.

NEXT, the manifold runner dimensions (BOTH) are needed inputs.

The patron request was a simple bore/stroke change report based on an OEM LS-3. (with cam upgrade)

ALL here are asked to provide their specifications AND EACH will have a custom report.

Lance

Patron

I can provide all the info or where to find it, there just normal aftermarket intakes. And the heads used would be Mamo AFR/TFS Ls3 heads for the big bore and Factory Ls3 heads ported by FRH as we have the listed flow for both. And let's just rev it to say 7000 to 8k Lance. Let me get up and get on my home CPU and not this I phone. If someone could post the Mamo Ls3 flow chart for either. Give me a second.

big hammer

So would a 3.5x5.25 vs a 4.155x3.75 engine have the same hp potential?

spanks13

iTrader: (5)

That's very true what I wrote was a sloppy statement. Was trying not to write such long posts lol.

My interpretation of the question is all things equal...4.030 x 4.00 vs 4.155 x 3.75" stroke.

Below peak torque yes the longer stroke engine should produce more horsepower. Peak torque should be the same or very extremely similar. Above peak torque I would expect to see the larger bore engine produce more power - and the higher the revs go the more disparity there will be.

Patron

A CID,Super Vic intake or MSD(ported or unported) can be used with a 4500 or 102 T/b depending. Let's keep the lift in the terms of safe so .750 lift and a duration of 266 to 270 @ .050. Can the 4 inch crank have around 2 to 4 degrees in intake duration to make things = as far as RPM and the stroker eating up duration.

Factory Ls3 heads from FRH for the 4.030 bore and 4 inch crank.

2.165

.200/159
.300/237
.400/282
.500/338
.600/368
.700/388
.750/390

Ex 1.590

.200/120
.300/190
.400/225
.500/242
.600/250
.700/255
.750/257


Mamo TFS Ls3 heads to be used with a 4.155 bore and 3.75 stroke

Lift.......Int....Exh

.200....151....125
.300....236....177
.400....297....218
.500....339....239
.550....359....246
.600....378....252
.650....383....258
.700....388....261

At the end let's do Cost to build each.

big hammer

What's the CSA difference between the two heads? A small difference in airflow means almost nothing

Patron

Mamo heads are 260 cc's if I'm not mistaken and the FRH are 268 cc no CSA is listed. Also how could you get that number(CSA) while doing it simply. I do know this More CSA helps in terms of RPM.

big hammer

Putting different top ends on two different engines and trying to get some kinda AH HA! Moment out of it is kinda funny

Patron

Oh no! It's, just is what it is don't back track now in terms of Money wasted for some crank combination that cost 3k more to start. Yea that's the AH HA! If you don't get over 50 hp money Wasted. As I know a 4 in crank would not even be a ? in terms of Hp / Tq. Let's play ball Smaller crank guys.

big hammer

Hard to play ball when scatterbrains keep moving the gaol
Post man

Patron

Don't hate the Messenger hate the game with that Short as stroke. Lance will post them and then we will all see. As of now your Higher number went in the trash @ 6k. You may as well extend the RPM to see if that helps LOL!

big hammer

OP asked about the potential difference. Not price per HP