ENRKyle20

I think there is more power to be had out of my engine, I think I can spin more RPM than my current 6000 rev limiter. I know valve train is generally the limiting factor but bottom end needs to be up to the job as well. I believe others here have built a very similar engine to me, where do you think red line is for this engine? Here is the specs:
(Cam Card & Balance Card Attached)

383 Stroker:

Bottom End:
2 Bolt Main LT1 Block - unmodified. Stock oil pump
Eagle CAST Crank (I know ouch)
Forged Eagle I Beam Rods W/ARP CapScrews
Forged Speed Pro Hyper -12CC Dish Forged Pistons
Clevite Bearings



Top End:
LE"2.5" Heads, LE2 Custom Grind BILLET Cam 236/236 .562/.562 107 LSA
Ferrea 2.00/1.56 Valves DBL Springs & Ti Retainers
1.6 Comp Cams Full Roller Rockers NSA 7/16 Stud
Hardened Trick Flow Guide Plates
LS7 Lifters
Comp Chromoly pushrods


Not sure if this matters for determining max safe RPM but I run a Cloyes True Roller Timing Chain Set








Supporting Mods & Stuff That Does Not Really Matter For Max RPM:

SLP cold air intake
Aluminum elbow
Twin 58MM Profesional Products Throttle Body
Loyd Ellot Ported Intake Manifold
42lb Racetronix Injectors
Racetronix 255LPH Fuel Pump
"Stage III" Clutch
Deleted Air Pump/Air Injection
Deleted EGR
Custom Tune By Solomon From LT1PCMTuning
LT4 Knock Sensor & Knock Module (Tuned Out Anyway)
ARP Flywheel Bolts


Balance Sheet With Rotating Assembly. (I had the flywheel neutrally balanced and I use a stock harmonic balancer)







And the Cam Specs:




Also, I am not 100% sure about the springs - Loyd said "if we did upgrade to the bee hive springs, I did not have it listed in my book but you can tell the difference in the dbl springs and the bee hives." I dont know!. Can you identify these?

(I know there is metal shavings in one of the pics, I had to grind a valve tip flat so I could cap it, it was wearing uneven because the guide plates were poop, I put good ones in now and capped the tip)








THANK YOU

Chimera96

you have a cast crank that many would agree is weaker than the stock one. With that said many run them without issue.

generally you don't need to spin a 383 as high as a 350. Mine is all forged bottom end w/4 bolt mains with a much smaller cam. It hits max power around 5700 rpm so I shift at 6400 max. my rev limiter is set at 6700 but I NEVER go past 6400 as it is done by then.

if your dyno shows you are still making power at 6k.....you could move the rev limiter up to 6500....it is just with your cast Eagle crank that is territory some would flinch at

if your cam peaks at around 5500-5700 rpm you really don't need any more that 6200-6300 rpm so set your rev limiter a few hundred rpm's above that

ENRKyle20

Excellent tips. thank you so much.

The only way to know what my cam peaks at will be on a dyno, correct? or is that something that can be roughly calculated with the cam card?

Thank you for your input :-)

Kevin Blown 95 TA

Do a banzai run and log it then export the data and plot 3rd and 4th gear rpm vs time in MS Excel and you'll see when it quits accelerating. You can do some runs on a measured course and adjust your rpm shift points each run and see which is your fastest time, then see where you were shifting at and it will help answer your question. You are looking for where your engine is the most efficient, then you rev above that a little bit so you shift back down into the power zone. You want to spend as much time in the power band as you can, not too much time above or below it. Some of that depends on gear/gear spread, too, but the principles are always the same.

ENRKyle20

Kevin that is brilliant, I have no idea why I never thought of that.. its essentially a dyno without HP reading for the purpose of tuning. I am going to do that today! Thank you

Chimera96

OP

not sure why your rev limiter is set at 6k. I assume you do have a tune for your current set up

did that tuner say why the rev limiter is set at 6k

BTW, your valve springs look like bee hives

regarding your guide plates....when you have your valve covers off look closely at RR tip on valves. They should be centered LtoR and not favoring one side which looks like what happened with your previous guide plate. If your new ones center the roller tip L/R correctly you are good. If not you will need to swap to the ISKY "adjustables". Many with LT1 heads, especially with larger valves have alignment issues that the ISKY adjustables will resolve. If your new ones are fine, great.

if you do have data log ability and can make a situation where you have a consistent speed within a clearly defined distance where you can accurately measure EXACT speeds you could then graph those results....but IMHO a dyno would be way more accurate. It will clearly show where you start to drop off on HP and also show if there is any break-up along that path which would indicate valve spring problems or ignition

generally you want to shift about 400-500 rpm past where your cam stops peaking HP

Mr99SS

Id put it at 6k

97WS6SCharged

I think I would stay conservative on that combo. 2 bolt mains, cast crank and a set of pistons that appear to be made of lead (630 grams!).