What Cam For My Forged 383??
04-05-2006, 07:05 PM
#21
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236/245 duration, .569"/.580",114 or 115lsa i have a very similar cam in my 6 speed 383 and it pulls 14hg vacuum and is still very drivable on the street. It would also do well on a blower/nitrous car. Just my opinion though i am by no means as knowledgable as Bret(sstrokerace) or Joe O. when it comes to cams but my car made good na power and awesome on the juice
04-05-2006, 07:31 PM
#22
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I have a CC extreme engery 230/236 with 112 LSA in my 383. Got some AFR 195 CC heads with 64 CC chambers. JE pistons with 10.5 compression. Before I chose my cam I spoke to Dave @ AFR and he told me not to go to big on the @.50 split(I/E). Anything bigger would hurt my performance.
Anyways here is my setup. Motor should be going in this weekend,
https://ls1tech.com/forums/lt1-lt4-modifications/466469-what-kinda-numbers-can-i-expect-383-1996-formula-ws6.html
Anyways here is my setup. Motor should be going in this weekend,
https://ls1tech.com/forums/lt1-lt4-modifications/466469-what-kinda-numbers-can-i-expect-383-1996-formula-ws6.html
04-06-2006, 08:31 AM
#23
T/A KID, you cant compare LS1 to LT1. The LS1s always use cams with less split due to the exhaust side of the head being alot better than the comparable LT1. That is why LS1s could get away with reverse split pattern cams.
The LT1s need more exhaust duration than the LS1s.
Jason
The LT1s need more exhaust duration than the LS1s.
Jason
04-06-2006, 11:08 AM
#24
Originally Posted by T/A KID
Bret I have been reseaching a lot of your threads and numerous others on Blower cams, From what I see a lot of people say run a wide I/E ratio dealing with duration (anywhere from 10,12+ split)
But lately I see a lot of guys going fast with smaller splits like around a 4-6 degree split especially the LS1 guys. Kp on this board (director in the forced induction section runs 9.48's at 144 with a tiny 204/211 01 Zo6 cam with out of the box Dart 225, forged 347 Ls1, 12.5 lbs of boost on his D1SC, with a 3340 race weight, backed with a 3;70 gear ration and a Th400, cuts 1.3 60 times. The car sounds stock besides the blower wine and the bypass valve
.
On my 383 I was thinking something with a 6 degree split with as much lift as I can throw at it using the stiffer big block Beehives. I firgure with boost running through the motor these springs would be my best choice.
When it comes to LSA at boost I have heard just about everything some wider than 114 and some narrower.
DO you car to GIVE A LITTLE BIT of FREE INFORMATION!
But lately I see a lot of guys going fast with smaller splits like around a 4-6 degree split especially the LS1 guys. Kp on this board (director in the forced induction section runs 9.48's at 144 with a tiny 204/211 01 Zo6 cam with out of the box Dart 225, forged 347 Ls1, 12.5 lbs of boost on his D1SC, with a 3340 race weight, backed with a 3;70 gear ration and a Th400, cuts 1.3 60 times. The car sounds stock besides the blower wine and the bypass valve
.On my 383 I was thinking something with a 6 degree split with as much lift as I can throw at it using the stiffer big block Beehives. I firgure with boost running through the motor these springs would be my best choice.
When it comes to LSA at boost I have heard just about everything some wider than 114 and some narrower.
DO you car to GIVE A LITTLE BIT of FREE INFORMATION!
The LSA is not the really important part, it's the valve events. If you don't have the intake events in the right spot then the cam isin't going to work. The large LSA's are there not to trap the charge, but to keep the motor driveable and enough idle vacuum. Low compression and off boost are two things that make for a crappy driving car.
The split all depends on the setup, but blowers do need more time (duration) to effectively make power in the higher RPM of the range you are running. That goes for both LS and LT motors.
Bret
04-06-2006, 02:38 PM
#26
T/A KID, you cant compare LS1 to LT1. The LS1s always use cams with less split due to the exhaust side of the head being alot better than the comparable LT1. That is why LS1s could get away with reverse split pattern cams.
The LT1s need more exhaust duration than the LS1s.
The LT1s need more exhaust duration than the LS1s.
Ben,
The LSA is not the really important part, it's the valve events. If you don't have the intake events in the right spot then the cam isin't going to work. The large LSA's are there not to trap the charge, but to keep the motor driveable and enough idle vacuum. Low compression and off boost are two things that make for a crappy driving car.
The split all depends on the setup, but blowers do need more time (duration) to effectively make power in the higher RPM of the range you are running. That goes for both LS and LT motors.
The LSA is not the really important part, it's the valve events. If you don't have the intake events in the right spot then the cam isin't going to work. The large LSA's are there not to trap the charge, but to keep the motor driveable and enough idle vacuum. Low compression and off boost are two things that make for a crappy driving car.
The split all depends on the setup, but blowers do need more time (duration) to effectively make power in the higher RPM of the range you are running. That goes for both LS and LT motors.
I had talked to Lloyd one day about cams and he said a lot of what you guys do is mess with the valve events, Is that half the battle.
Bret the AFR's that I had LE send you are the heads I am using for my D1SC 383, I measured around a 80% I/E ratio on the heads 288/216 at .600.
Do blower cars need a wider duration split, Even when the heads are in the 80%+ I/E ratio??
Lastly Bret I am trying to put together a very driveable street car with this setup, I want to go mild on the cam and not have very much Overlap, can having not enough overlap hurt performance or driveability on a Blower car.
The main reason I canceled the 396, super vic, 7000 RPM motor is I thought I would have more fun and DRIVEABILITY with a charger. I drive this car everyday.
Thanks for any advice.
04-10-2006, 07:50 PM
#27
Ben,
Actually in the running condition of a LT1 motor the E/I ratio is around 80-85%
FWIW the E/I ratio is not as big of a deal as most put on it, but with tweaking that you can get better power and drivability.
Overlap on a blower car is important, not as much so as a NA car, but it doesn't hurt like blower guys think it does.
How driveable do you want it? I've been test driving a setup that I have in the shop on a LS1 car with a mail order tune from Bryan and that setup is not bad at all. Nice on the highway, with just low speed bucking, and we are talking about a cam with more overlap than a MS3 cam.
Bret
.
Actually in the running condition of a LT1 motor the E/I ratio is around 80-85%
FWIW the E/I ratio is not as big of a deal as most put on it, but with tweaking that you can get better power and drivability.
Overlap on a blower car is important, not as much so as a NA car, but it doesn't hurt like blower guys think it does.
How driveable do you want it? I've been test driving a setup that I have in the shop on a LS1 car with a mail order tune from Bryan and that setup is not bad at all. Nice on the highway, with just low speed bucking, and we are talking about a cam with more overlap than a MS3 cam.
Bret
.
04-11-2006, 02:23 PM
#29
How driveable do you want it? I've been test driving a setup that I have in the shop on a LS1 car with a mail order tune from Bryan and that setup is not bad at all. Nice on the highway, with just low speed bucking, and we are talking about a cam with more overlap than a MS3 cam.
Bret I can't recall how to Figure in the Overlap of a cam. A guy on this board ran a 224/230 cam on a 112 LSA and his LT1 traped 140+ with his blower and still had Less Overlap than a 224/236 on a 114 LSA.
04-11-2006, 03:02 PM
#30
Yep....
If you look a the cam in terms of intake and opening numbers you just take the Intake opening point and the exhaust closing point and add those numbers together, that will get you the overlap at .050" duration or advertised duration.
With less compression the cam gets worse to drive so that's one problem with blower setups. The big issue I have found with most blower cams is the placement of the valve events. There was a good article on cam swaps in a blown motor that Mike Petralia did for Engine Masters last summer/fall time. I wish he would have called me up (since I know him pretty well) and asked for a cam, he FOUND something there, he just didn't come up with the right conclusion, actually the best test i've seen in a magazine on camshafts.
Bret
If you look a the cam in terms of intake and opening numbers you just take the Intake opening point and the exhaust closing point and add those numbers together, that will get you the overlap at .050" duration or advertised duration.
With less compression the cam gets worse to drive so that's one problem with blower setups. The big issue I have found with most blower cams is the placement of the valve events. There was a good article on cam swaps in a blown motor that Mike Petralia did for Engine Masters last summer/fall time. I wish he would have called me up (since I know him pretty well) and asked for a cam, he FOUND something there, he just didn't come up with the right conclusion, actually the best test i've seen in a magazine on camshafts.
Bret
