383 Stroker help

**99Ls1fever** · 12-26-2007, 05:38 PM

I am currently biulding up an LS1 383 stroker kit, and had a few questions, below are all the specs of the pieces going into it. The intake will be a LS6 manifold, with possibly a 85 mm TB. My first question is related to compression ratio... if I use the Stage 3 heads, I would guestimate a 10.7:1 ratio, is that too high for daily driving on 91 octane gas at 5,000 ft. elevation? (I live in Colorado) Also, I am willing to deal with a "fairly" radical cam, but this is a daily driver, according to the cam company they said this is the biggest one I can run on the street, any experience with something this big? Is it TOO big? And my last question, is should I be running the Stage 2, or Stage 3 heads? I am trying to get every ounce out of this motor, and I know that if I go too large on runners, intake valve size, and such that I could loose intake velocity, and I wouldnt want to do that, am I in danger of having that happen if I go with the Stage 3 heads?

383 STROKER FROM EAGLEChevy LS1 Balanced Assembly
383ci
Bore Diameter: 3.905"
Stroke: 4.000"
Rod Length: 6.200"
Piston Type: Flat Top @ -2cc
Comp Ratio:
11.3:1 with 64cc head
11.0:1 with 66cc head
10.4:1 with 72cc head

Camshaft specs: Magic Stick V.4 239/242, .649"/.609" Camshaft With Your Choice of Lobe Seperation (111 LSA Standard)

Cylinder Heads: Stage 2 and Stage 3
Stage 3:Patriot Performance LS6 5.7L Stage III Head Assy (2.08/1.60/64cc)
Stage 3:Patriot Performance LS6 5.7L Stage III Head Bare (2.08/1.60/68cc)
Stage 2:Combustion Chamber Volume (cc): 67
CNC Machined Combustion Chamber: Yes
Intake Runner Volume (cc): 213cc
Exhaust Runner Volume (cc): 78cc
Intake Valve Diameter (in): 2.020 in.
Exhaust Valve Diameter (in): 1.570 in.

Thanks for your time,

99LS1FEVER

**silverz28camaro** · 12-26-2007, 06:25 PM

sounds like you have alot of work and fun ahead of you. very good choice on the cubic inches choice, 383 will provide lots of TQ and have the ability to pull hard up top. As far as the heads go, you can't go wrong with the afr 205cc head, they have been know to be the best heads for many chevy motors. these are the ones i am saving for right now. They should get me around 40-50 hp even with my stock cam. look into these heads alittle more.

As far as compression ratio...rule of thumb is on pump 93 you can go 10.0:1 on iron heads and 11.0:1 on aluminum heads.

I don't know a whole lot about what can you would want but give comp cams a call and see what they suggest. You may want to rethink about running a cam with over .600 lift. there are many cams out there that have a better profile with only .590 lift, and having slightly less lift will give room for more high rpm valve train stability. big inch motors need more duration, not more lift. i would aim in the .580-.590 lift range with plenty of dur. having the high compression will love a cam with lots of duration.

Good luck, take your time, and see all your options. And remember, there are many different ways to build a motor, everyone has something different that works, Its all on how you piece them together to make em work even better.

**lstvr** · 12-27-2007, 12:39 AM

I have had a 383 stroker for around a year, I have JUST put Dart 225 heads on it, it boosted my midrange, but i think this was due to the hike in comp ratio, i run 98oct fuel over here. When i built my motor i put too small a cam in it 222/224 comp cam, and the motor would not rev freely. However when i put 1.85 rockers on it, it was up 65bhp@6000rpm. The lift at the valve equates to around .62. I am booked on the rolling Road Late Jan to have the heads dialled in so i'll see what i have actually got out of them, i cant let it rev out on the road here as its wet and it spins up in the 1st 4 gears.

**99Ls1fever** · 12-28-2007, 09:24 PM

I appreciate your guys in put, but that isn't awnsering the question that I asked. duration is bad and kills your vaccum so I dont know why you would say I need more duration.(not what i asked about). I just need people that honestly know what they are talking about instead of paying a shop to do the work, and just preaching.

**tylerdurden1** · 01-02-2008, 09:19 PM

Also remember that the scr is one thing and the dcr is the part that will let you know about detation with a cam using the duration. This is my formula for my up and comming 402 the piston .010 out of the hole with -10cc valve reliefs using ls6 heads on .050 gaskets.The compression ratio is 11.13 scr and dcr is 8.66. I will be using a G5X2 cam (232/240 595/608 with a 112 sep. forgot one thing 4.00 bore, 4.00 stroke w/ 6.125 rods

**slims00ls1z28** · 01-04-2008, 05:21 AM

As far as cam being "too" big that's a personal choice on what you can live with. I have a magic stick v3 which spec wise is only smaller on intake lift on an otherwise stock engine and drove mine on the street alot (100 miles round trip to work every weekend). It would have brake issues sometimes when you first start it but that was it. With it tuned I could cruise all day in traffic with the air on and be fine as well. I could stand outside the car and cold start it without touching the gas and it would fire right up, so to me it was streetable (3600 stall, 4.11 locker in all). The car did not like being in OD doing about 30 mph though it would buck sometimes and I'd have to drop it out of OD. But this was my stock 346 with stock heads. With a 383 it should eat up some of the cam and make driveability a little bit better.

I'm sure your 383 could make use of the stage 3's but not with the LS6 intake. On this application the LS6 is your bottleneck. Not sure if they can keep up with Stage 2's much less 3's. As far as your 383 combo is concerned I highly doubt the Stage 3's will hurt velocity in your case at all. That 383 can handle it. A set of fully ported C5R's might be another story but The 383 should handle the patriot stages 3's with that cam.

**lstvr** · 01-04-2008, 10:07 AM

Just had a cam specced for me by a well recommended guy, so will be having a custom grind- 232/236 .625/.629 113+2. I asked for a shift point of 6600rpm, limiter 6800. I also stated 95% road use.

**therel82** · 01-05-2008, 03:10 PM

I'm havig the same problem here too. I'm buying a 383 cid LS1/LS6 Aluminium Stroker Short Block from Texas Speed, but I dont know what head and cam should I get with it. I'm trying to get an all motor setup with a medium/big cam with no poweradder I need this setup to be good for a long time because this car is my daily driver and money don't grow on trees so this car will be getting drow for a long time.

This is what I had in mind.

383 cid LS1/LS6 Aluminium Stroker Short Block

Precision Race Components LS6 64cc Stage 2.5 Cylinder Heads Fully CNC Ported & Assembled With Stainless Steel 2.02" Intake Valves, 1.57" Exhaust Valves, & PRC Dual Valve Spring Kit with Titanium Retainers, Rated to .660" Lift. Kit Also Includes TSP Hardened Pushrods

The Texas Speed 228/228 .588/.588 Camshaft 112 degree

But I dont what size rocker arms should go with this? With all this been said would this setup get me 450rwhp/450rwqt with a good tune. If you all would give me some good advice also please thank you.

**99Ls1fever** · 01-05-2008, 06:27 PM

Originally Posted by slims00ls1z28

As far as cam being "too" big that's a personal choice on what you can live with. I have a magic stick v3 which spec wise is only smaller on intake lift on an otherwise stock engine and drove mine on the street alot (100 miles round trip to work every weekend). It would have brake issues sometimes when you first start it but that was it. With it tuned I could cruise all day in traffic with the air on and be fine as well. I could stand outside the car and cold start it without touching the gas and it would fire right up, so to me it was streetable (3600 stall, 4.11 locker in all). The car did not like being in OD doing about 30 mph though it would buck sometimes and I'd have to drop it out of OD. But this was my stock 346 with stock heads. With a 383 it should eat up some of the cam and make driveability a little bit better.

I'm sure your 383 could make use of the stage 3's but not with the LS6 intake. On this application the LS6 is your bottleneck. Not sure if they can keep up with Stage 2's much less 3's. As far as your 383 combo is concerned I highly doubt the Stage 3's will hurt velocity in your case at all. That 383 can handle it. A set of fully ported C5R's might be another story but The 383 should handle the patriot stages 3's with that cam.

Thanks Man, that was great information. I appreicate the wisdom handed down...

**99Ls1fever** · 01-05-2008, 06:32 PM

Originally Posted by lstvr

Just had a cam specced for me by a well recommended guy, so will be having a custom grind- 232/236 .625/.629 113+2. I asked for a shift point of 6600rpm, limiter 6800. I also stated 95% road use.

what did he say when you told him you where going to use it 95% of the time for road use? did he think it would be fine?

**lstvr** · 01-06-2008, 12:41 AM

Originally Posted by 99Ls1fever

what did he say when you told him you where going to use it 95% of the time for road use? did he think it would be fine?

I filled in a 3 page A4 sized form giving ALL the specs of my car and the mods, and how it will be used. This guy came highly recommended, and said that my 222/224 cam was WAY too small, and the cam spec he has provided will pick up a "whole bunch more mid and top end". I've ordered the cam, so it has to be ground and then sent here to the UK, as soon as i have installed and dynoed it i will post the results.

**99Ls1fever** · 01-06-2008, 07:58 PM

Originally Posted by lstvr

I filled in a 3 page A4 sized form giving ALL the specs of my car and the mods, and how it will be used. This guy came highly recommended, and said that my 222/224 cam was WAY too small, and the cam spec he has provided will pick up a "whole bunch more mid and top end". I've ordered the cam, so it has to be ground and then sent here to the UK, as soon as i have installed and dynoed it i will post the results.

yea that will be nice, then we can definatley get a feel for the cam...

**99Ls1fever** · 01-13-2008, 08:07 AM

No Worries, on this 383 question, I am just going to go through Texas Speed and have them do a 408 for me. I was having to many problems finding machine shops and there knowledge of the LS1 at this time. So Texas Speed will be the awnser I needed. Thanks to all who helped with this tread.

**mghawk57** · 01-16-2008, 08:27 AM

If you don't mind me asking 99LS1fever whan are you paying for the motor and what heads and cam did you decide on.I have been pricing motors for the last 45 days trying to decide.I am a little differant with 12 psi on a Procharger set up,but was wondering on yours.Thanks

**99Ls1fever** · 01-16-2008, 05:27 PM

Originally Posted by mghawk57

If you don't mind me asking 99LS1fever whan are you paying for the motor and what heads and cam did you decide on.I have been pricing motors for the last 45 days trying to decide.I am a little differant with 12 psi on a Procharger set up,but was wondering on yours.Thanks

I am buying everything tommrow, from Texas Speed Performance The short block 408 is $3,600 and I am getting the Texas Gaint Camshaft which is $390 and the last thing I am getting with TSP is the pushrods which are $100. Then I am buying the Stage 3 Patriot Performance Heads through Summitracing for $1226 and the LS6 Intake manifold for $485 and then taking the rest off my LS1.

**mghawk57** · 01-17-2008, 03:57 AM

Thanks - I'm guessing you are putting the motor together? Good luck on your set up.

**99Ls1fever** · 01-17-2008, 08:35 AM

Thanks man, I might put the motor together myself it depends on the time I have this spring, otherwise its going to have to go to the shop to have its heart transplant... When I ordered everything today the quoted the compression to be 11.1 so im definatley going to make sure shit gets assembled correctly when my buds are over...

**slims00ls1z28** · 01-17-2008, 09:40 AM

Originally Posted by 99Ls1fever

I am buying everything tommrow, from Texas Speed Performance The short block 408 is $3,600 and I am getting the Texas Gaint Camshaft which is $390 and the last thing I am getting with TSP is the pushrods which are $100. Then I am buying the Stage 3 Patriot Performance Heads through Summitracing for $1226 and the LS6 Intake manifold for $485 and then taking the rest off my LS1.

All sounds good except I'm sure that LS6 will be choking your combo, that 408 and cam will be begging for a FAST 90/90. Not sure if the short block comes with oil pump but if it does not do not reuse the one out of the LS1 get a new one preferrably LS6 or better.

**99Ls1fever** · 01-17-2008, 09:45 AM

Originally Posted by slims00ls1z28

All sounds good except I'm sure that LS6 will be choking your combo, that 408 and cam will be begging for a FAST 90/90. Not sure if the short block comes with oil pump but if it does not do not reuse the one out of the LS1 get a new one preferrably LS6 or better.

Why is that with the oil pump? or getting a LS6 Oil pump?

**Sleeper101** · 01-17-2008, 09:51 AM

Not sure if you had the same problem or Not but just recently about 3 weeks ago Eagle sent us 2 different cranks and both were bad! We put them on the balancing machine and they were way out of round. So they finally hand picked us a good crank. I think they ran into a batch of bad cranks. The first 2 we received looked used. The journals were all scuffed up and not polished. But eagle was very cool and helped us figure out the situation. Good luck on your build Im firing mine up hopefully this weekend.

Mines a little different application tho. Its the Lt1 383 stroker.

The compression we figured on mine was 11:0 But im using stock heads and cam! Im a poor boy! Hopefully can upgrade that stuff later.

I have assembled the motor myself but parts and machine work on mine came to 2100$ for short block. I think you could save A grand by parting one together and building it yourself. But if you got the money to spare thats cool! I like saving every dime I can personally!