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  #16 (permalink)  
Old 09-12-2019, 03:17 PM
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Quote:
Originally Posted by vinniekq2 View Post
you are building this truck bass ackwards and will burn a tonne of money to be disappointed in the performance gained.
Start with the truck
set diff up for maximum traction and weight transfer. Build/buy transmission that is your final choice. TKO 600 might live. Get some racing tires. Use a cheapo/stock engine (3500)
put a cam in it (cheap solid lifter) that will take you to 5500 rpm

get lots of track time
get more track time
Plan the replacement engine as a drop in for a year in the future
probably a 540/auto
get to the track
learn to drive
make it reliable
Im not sure why I did it this way. But in the end I will probably have the same parts anyways so order is not that important to me. It will be cool to see how much faster it is when I put in a 5 speed transmission, then the rear gears. I'm not going to spend anything extra because Im going to use all the parts. If I buy a part I'm using it. I know buying two more engines is more money and time than buying one. I know it wont be that fast until I get the transmission,axle gears,tires, and suspension to hook up. All those parts are next on the list.

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  #17 (permalink)  
Old 09-13-2019, 12:19 PM
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Quote:
Originally Posted by 2001Blazer4x4 View Post
Buy this. https://www.skipwhiteperformance.com...nk-rods_89381/

Add a Comp Cams XR276HR or Comp Cams XR282HR, an Air Gap manifold, and a 750 Holley/Quick Fuel 4-corner idle with vacuum secondaries. Use 1 3/4" headers.

Only thing holding you back will be your heads. You may need to change valve springs on these heads as AFAIK Blueprint heads come with valve springs that aren't really very strong.
Thanks! I was planning on getting the edelbrock RPM air gap, 1+3/4 headers, 750 carb.

Should I get the valve springs that are recommended for the cam? or just get some that are a little bit stiffer?

Is the victor JR too big for this engine? The rpm range is 3500-8000, and I think there is another one that is 3,500-7000. The air gap is 1,500-6,500. I was thinking the victor JR would be sluggish at lower rpms but then at a certain rpm it would be better than the air gap? and the air gap would be good all around. But if I'm driving at 3500-6200 wouldn't the victor jr be better? I will probably run the air gap to be safe. Just curious about victor jr and how it would work. Wouldnt the victor jr be good for like road racing type of power band for this engine but not good for drag racing?
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  #18 (permalink)  
Old 09-13-2019, 01:10 PM
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Quote:
Originally Posted by 2001Blazer4x4 View Post
Springs:
  • Spring Pressure Open: 295-305 @ 1.225
    Spring Pressure Closed: 115-125 @ 1.800
    Outside Diameter of Outer Spring (in): 1.437 in.
    Dual Valve Springs

Comp Cams Valve Springs 986-16
Valve Springs, Dual, 1.430 in. Outside Diameter, 322 lbs./in. Rate, 1.150 in. Coil Bind Height, Set of 16
Installed Height (in): 1.750 in.
Seat Pressure at Installed Height (lbs): 132 lbs.
Open Height (in): 1.250 in.
Open Pressure (lbs): 293 lbs.

I'm really surprised but these really look like the same springs Blueprint has, but set up at slightly tighter installed height to get the higher seat pressure. So I have to back off on your needing the Comp Cams Springs. You might want to consider throwing a 0.040 or 0.050 shim under the Blueprint springs and checking for coil bind. If OK - go ahead and try running them.

Don't bother with the Vic Jr with the Blueprint heads. You will kill your low end with the single plane manifold and the heads will prevent any significant gains on the top end. These two cams work quite well in a 383 at 2500-6000 rpm - valvetrain is heavy with a hydraulic roller and it's difficult to spin them much above 6500. No need to spin it higher that 6000 if it can't breathe anyway.

I know I keep poo-pooing your heads so I will say this. What we are describing is a 400+HP 383 - maybe 425 HP, more or less. That should put a 4000# truck into the high 12 second bracket if you can get it to hook up and can keep the engine in it's power band. Go to good heads and this is a 500HP build. Personally I think you are going to destroy manual transmissions and clutches - and the original granny lo trans will be worthless at the track - better to go with an automatic and a good converter. At least get a rev limiter for when you miss a shift.

Remember that it takes probably 10HP for each 0.1 second faster - so that would be low 12's. Every 100# you shave off in weight knocks off another 10th - so lose 500# and go 0.5 sec faster. Could be a lot cheaper than building another 50 HP into the engine.

Last edited by 2001Blazer4x4; 09-13-2019 at 01:37 PM.
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  #19 (permalink)  
Old 09-13-2019, 05:36 PM
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Quote:
Originally Posted by RobbyDD View Post
Thanks! I was planning on getting the edelbrock RPM air gap, 1+3/4 headers, 750 carb.
If ALL the motor will ever do is to drag race up to 6500 rpm's and will never be modulated and used as a street motor, then the RPM AIR GAP is the manifold for you. If the motor will ever be used on the street, then drop the "Air Gap" part of it and bolt on a Performer RPM (assuming 6500 rev limit).

Quote:
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Should I get the valve springs that are recommended for the cam? or just get some that are a little bit stiffer?
Yes, always use a matched package of parts from the cam grinder. He's the one who knows what works with his cam and what doesn't. After you have a few years of experience building motors, you will be able to choose all the components yourself.
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Old 09-14-2019, 03:27 PM
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Thanks for the info!

The truck will be primarily for the track. I will drive it to the track though because I don't have a trailer and another big truck. I was thinking the RPM Air gap because it will be for the track. I also thought the air gap would help with the higher compression because it keeps the air and fuel mix at a lower temperature because its separated from the lifter valley, help with detonation? Maybe more brainwashing from the internet.

Choosing the right springs for a cam seems complicated. It depends on RPM and lift right? So the valves don't float at high rpm and don't bind with the lift?

What would I need for the 500 hp? Better heads and the vic jr, different cam? or just bigger heads and same cam and rpm air gap?

I'm considering getting the profiler heads or maybe those blueprint heads next size bigger than the one I got. They are both the same price. Since I'm already buying all this stuff it would only be 700 more to get 80 hp? Then I could start reducing weight on the truck. 500 hp is enough for me. So I would get the cheaper heads.

I'm going to try and find some money to buy the big heads.
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  #21 (permalink)  
Old 09-14-2019, 04:17 PM
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Quote:
Originally Posted by RobbyDD View Post
Thanks for the info!

The truck will be primarily for the track. I will drive it to the track though because I don't have a trailer and another big truck. I was thinking the RPM Air gap because it will be for the track. I also thought the air gap would help with the higher compression because it keeps the air and fuel mix at a lower temperature because its separated from the lifter valley, help with detonation? Maybe more brainwashing from the internet.

Choosing the right springs for a cam seems complicated. It depends on RPM and lift right? So the valves don't float at high rpm and don't bind with the lift?

What would I need for the 500 hp? Better heads and the vic jr, different cam? or just bigger heads and same cam and rpm air gap?

I'm considering getting the profiler heads or maybe those blueprint heads next size bigger than the one I got. They are both the same price. Since I'm already buying all this stuff it would only be 700 more to get 80 hp? Then I could start reducing weight on the truck. 500 hp is enough for me. So I would get the cheaper heads.

I'm going to try and find some money to buy the big heads.
Valve springs depend on a lot of things. Cam lobe profile (how fast it opens, as well as how far), valve train weight and RPM amongst others. Don't need the Vic Jr or a different cam - just the good heads.

Last edited by 2001Blazer4x4; 09-14-2019 at 04:22 PM.
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  #22 (permalink)  
Old 09-14-2019, 05:34 PM
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Quote:
Originally Posted by RobbyDD View Post
Thanks for the info!
Quote:
Originally Posted by RobbyDD View Post
The truck will be primarily for the track. I will drive it to the track though because I don't have a trailer and another big truck. I was thinking the RPM Air gap because it will be for the track. I also thought the air gap would help with the higher compression because it keeps the air and fuel mix at a lower temperature because its separated from the lifter valley, help with detonation? Maybe more brainwashing from the internet.
I don't know Robby, who's to say. Do what you feel is the right thing to do. I think it's all a tempest in a teapot anyway.
The way to protect the motor from detonation is to use the proper fuel for the static compression ratio used, engineer for the thinnest squish/quench, deburr everything in the combustion chamber including the first few threads of the spark plugs and use the coldest plug you can to begin testing. Hopefully you know that spark plugs come in different heat ranges. The way to tell when you have found the correct heat range is to make a hard, full pass and then pull the plugs to inspect the ground strap. It will be two different colors along its length. You want the color change to be halfway between the plug body and the end of the strap. These first couple of photos will show you what I'm talking about....
Wallace Racing - Spark Plug Reading

Quote:
Originally Posted by RobbyDD View Post
Choosing the right springs for a cam seems complicated. It depends on RPM and lift right? So the valves don't float at high rpm and don't bind with the lift?
Yeah, that's pretty much right. It's pretty easy for a newbie though. You call up your favorite cam grinder and tell him what heads you have and what you want the motor to do and he sends you the cam, the lifters and the springs as a package. No guessing.

Quote:
Originally Posted by RobbyDD View Post
What would I need for the 500 hp? Better heads and the vic jr, different cam? or just bigger heads and same cam and rpm air gap?
Minimum 383 cubic inches, 10.5:1 static compression ratio, heads that will flow minimum 280 intake and 200 exhaust @0.500" valve lift, 1 5/8" tuned headers, 750/850 carb, high-rise dual-plane intake manifold, cam with minimum 235 degrees intake duration @0.050" valve lift. Please stop with the Air Gap. It's nothing. It's just a way for Edelbrock to sell more parts and they should be ashamed of themselves. It's crap.

Quote:
Originally Posted by RobbyDD View Post
I'm considering getting the profiler heads or maybe those blueprint heads next size bigger than the one I got. They are both the same price. Since I'm already buying all this stuff it would only be 700 more to get 80 hp? Then I could start reducing weight on the truck. 500 hp is enough for me. So I would get the cheaper heads.
Profiler 195's will make 500 hp.
Airflow Research 195's will make 500 hp.
Blueprint heads will hold the shop door open in nice weather.

Quote:
Originally Posted by RobbyDD View Post
I'm going to try and find some money to buy the big heads.
Whatever.
.
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  #23 (permalink)  
Old 09-15-2019, 09:38 AM
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Im with Richard on what he says above,,,
you are now asking silly questions,IE:
rpm VS rpm air gap VS Victor jr?
its not a solid question
when you build an engine you start with a piece of paper
plan a parts list
all the parts need to match, they all work together

You have to answer how much power you are going to squeeze from the plat form you choose.
dual plane intakes generally use bigger carbs than single planes
you randomly mentioned 750,,,,,,too small for either of the intakes (FOR RACING)

start with engine to use
then choose heads to flow enough air to get your hp requirements
now you calculate the rpm you need to get the power
higher rpm range requires a proper carb/manifold combo to mix fuel (or injection)
the camshaft is now chosen to give the valve timing required to breathe deeply enough to get the rpm required
if the engine is big enough to easily make the power you wont have to maximise the cr to the point of needing exotic fuels
headers primary size and tube length is tuned to help with best scavenging at operating rpms

this is where you start

easy "GUIDELINE" 1.5 hp/cubic inch is a borderline max for a race engine that could see limited street use

383 x 1.5 = 574.5 hp

road race engines are slightly lower as their cam timing specs are for a wider powerbands
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Old 09-15-2019, 07:28 PM
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Okay thanks for the information!
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Old 09-18-2019, 03:44 PM
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Do I need a small base circle cam for this block? I'm using the 1 piece roller block. Does the small base circle cam only apply to 383 strokers that use the 2 piece block?
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  #26 (permalink)  
Old 09-18-2019, 04:11 PM
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Cam to Crank center is the same on all the blocks.
Connecting rod to cam clearance is the issue with the stroker crank.
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Old 09-18-2019, 04:13 PM
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From your original post:



I also got scat forged steel connecting rods that are clearanced for the stroker,
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  #28 (permalink)  
Old 09-18-2019, 06:36 PM
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Quote:
Originally Posted by RobbyDD View Post
Do I need a small base circle cam for this block? I'm using the 1 piece roller block. Does the small base circle cam only apply to 383 strokers that use the 2 piece block?
Depends on the camshaft, the camshaft timing, and the rods used. Degree your camshaft and then test the clearance but be careful not to run the rods into the camshaft. I like to cut a double thickness of hard cardboard (like used for behind carbon copies) into a shape I can hold onto (about 11" long) while placing between the rod and cam lobe as they pass each other. Just lay it on the cam lobe and turn the crank. You need to do every one as only some can hit. These sheets of cardboard are 0.020" thick, so I ensure 0.040" clearance. Most of the aftermarket rods these days will clear a moderate lift camshaft that is not small base circle. My rods have cleared three very different camshafts in my 383. Don't forget P/V clearance too, especially with 1.6 rockers.

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Last edited by 2001Blazer4x4; 09-18-2019 at 06:47 PM.
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Old 09-18-2019, 06:39 PM
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Small base circle cams are not desirable if you don't need one. Positions lifters lower in the bores and also requires longer push rods

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Old 09-18-2019, 07:19 PM
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The only way to get more lift is make the base circle smaller. Otherwise the cam won’t fit in the cam bores.
Hence the need for bigger cam bores for lifts to .900ish.
Also, the bigger camshaft journals make for a stiffer cam.
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