Thread: 383 build-Something Caught My Eye

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Originally Posted by pat mccarthy

cam i used was 224/230 480/480 lsa 110 in at 108.. TQ is what gets you rolling from the get go i take TQ over Hp any day to pull we have cams that make over 1000+ tq on a small shot of Nos hard to beat that. thats the seat of your paints feel as you get nailed in the seat with the big engine and bust weak drive train parts

The torque side of street vehicles I know about that and agree.You know it's a typical cake and eat it too question about hp.LOL.

Naw-this old boy isn't going to get hooked on the bottle.$$$ refills.

Still playin' around with this tow motor....
Custom cam 206/214, 106/113/109.5, 0.420"/0.420, (-3)(29)(40)(-6) installed straight up.
Streetmaster intake manifold (1st design).
http://cgi.ebay.com/ebaymotors/Edelb...Q5fAccessories
RPM HP TQ
1000 88 461
1500 149 521
2000 204 535
2500 247 520
3000 289 506
3500 319 478
4000 346 455
4500 357 417
5000 348 366
5500 319 305
Peak BMEP 210.8 @2000. This is some serious cylinder pressure, so a very tight squish (I would be thinkin' 0.035" to 0.040" with a D-cup piston) would be mandatory to prevent detonation on pump gas.

This version is what I am talking about wanting to try to find a 400ish HP output.Need some input to that.

Originally Posted by techinspector1

Still playin' around with this tow motor....
Custom cam 206/214, 106/113/109.5, 0.420"/0.420, (-3)(29)(40)(-6) installed straight up.
Streetmaster intake manifold (1st design).
Edelbrock Streetmaster Intake SBC Small Block Chevy | eBay
RPM HP TQ
1000 88 461
1500 149 521
2000 204 535
2500 247 520
3000 289 506
3500 319 478
4000 346 455
4500 357 417
5000 348 366
5500 319 305
Peak BMEP 210.8 @2000. This is some serious cylinder pressure, so a very tight squish (I would be thinkin' 0.035" to 0.040" with a D-cup piston) would be mandatory to prevent detonation on pump gas.

gary clear your pm mail so i can send you your PM

Originally Posted by pat mccarthy

gary clear your pm mail so i can send you your PM

PM's cleared Pat

Wow Richard!!!.Well the Icon's pistons #9926 for this build is in the hands of the machine shop to be bored..030 over on 5.7 rods @0 deck.They are a step dish.






That is 9.4 C/R with RHS#12001 72cc heads and a intake runner of 180cc.

Originally Posted by 1gary

That is 9.4 C/R with RHS#12001 72cc heads and a intake runner of 180cc.

No, here is a copy of what I figured in post #47...
I'd use the 12410 heads. With your 18cc pistons, in the hole 0.010" and a 0.040" gasket, you'll be at 9.4:1 static compression ratio. The 12410's have bronze guides, 64cc chambers, 2.02"/1.60" valves, +0.100" long. I might order the heads bare from Competition Products along with the valves, springs (part number on the timing card linked here), etc. and have Pat put 'em together.

You can use anything you want. I was just trying to follow along. The custom cam I suggested in post #63 works real well with the 9.4, but you won't have 9.4 if you run a different chamber size. Also, I don't like those pistons. The only squish there is....is a thin ring of material above the rings. Ain't gonna be much squish there. Might work ok, but they wouldn't be my choice for a high cylinder pressure motor.

Richard that is my fault.I'm sorry for the misleading info.
We looked at 0 deck and a 72cc head.Wanted a 170 cc runner but they in RHS tq'er's are not available in a 72cc head.I am insisting in RHS's clean tech.So the compromise to the RHS 12001 Pro action was made.72cc head/180cc intake runner.

The other thing was a compromise was the pistons.For what seemed like forever I was going with Mahle#SBC42530I26.Those would have been over $700 special order.I couldn't justify that cost for my use.So the Icon's seem to be a good buy and compromise.They have a offset pin to help quiet them down and a forged top for durability with floater pins and locks for $329 + 11 and change for shipping.

So I am very sorry not to keep you up to speed on these moves.I promise to do better in the future.I needed to make these decisions to get this build going and out of limbo where it has been setting.AND I need you input and support.

Thank You.

Richard that is my fault.I'm sorry for the misleading info.
We looked at 0 deck and a 72cc head.Wanted a 170 cc runner but they in RHS tq'er's are not available in a 72cc head.I am insisting in RHS's clean tech.So the compromise to the RHS 12001 Pro action was made.72cc head/180cc intake runner.

The other thing was a compromise was the pistons.For what seemed like forever I was going with Mahle#SBC42530I26.Those would have been over $700 special order.I couldn't justify that cost for my use.So the Icon's seem to be a good buy and compromise.They have a offset pin to help quiet them down and a forged top for durability with floater pins and locks for $329 + 11 and change for shipping.

So I am very sorry not to keep you up to speed on these moves.I promise to do better in the future.I needed to make these decisions to get this build going and out of limbo where it has been setting.AND I need you input and support.

Thank You.

all cam on list make 550to525 of TQ with 9.1 cr Erson E119811. 214/214 480/480 110....E119813.219/219.480/480..110 and some Elgins e136. 210/215 462/470 110 but work better at 112. this looks good abit broader e1135..230/230..480/480. thing is with the custom cam .you have to fined the master s for the lobe or on file and a core so there is some times a trade offs so a custom would be fine but after spending more time on this there is many shelf cams that will get the job done

Originally Posted by pat mccarthy

all cam on list make 550to525 of TQ with 9.1 cr Erson E119811. 214/214 480/480 110....E119813.219/219.480/480..110 and some Elgins e136. 210/215 462/470 110 but work better at 112. this looks good abit broader e1135..230/230..480/480. thing is with the custom cam .you have to fined the master s for the lobe or on file and a core so there is some times a trade offs so a custom would be fine but after spending more time on this there is many shelf cams that will get the job done

I have read this before on EFI's and cam choices.

Fuel Injection Engine Camshafts:

For a camshaft to work in a fuel injected application, it needs to make a good vacuum signal.
To create a vacuum signal, that stands a reasonable chance at working in an application without having to re-flash the ECM computer, a camshaft needs to be:

a) Short Duration : 220-222 Degrees @ .050” Maximum

b) Wide Lobe Separation/Centers: 112 to 114 degrees Minimum
Do not attempt to install a camshaft with a 108 lobe separation in a fuel injected engine, unless you are planning to re-program the ECM computer.

There are camshafts that are ground to work within the stock ECM computer parameters. Usually these camshafts have 208/208 degrees duration @.050” (intake/exhaust) and 112 degrees of lobe separation, or 208/214 duration with a 114 L/C

Both of these camshafts would be designed to function in stock CID engines/stock compression and stock computer programming.

However, if the cubic inches of the engine or compression ratio is larger than stock, the camshaft grind needs to grow accordingly and a custom camshaft would be in order.
Also, having the computer re-programmed/re-flashed is recommended with any camshaft change, even the “no hassle/safe” type grinds.

While the camshaft may work with the stock fuel/timing curve programmed into the ECM unit, it will not be working at its optimum level…..Think of it along the lines of taking a performance carburetor out of the box, bolting it onto the engine, hooking up the fuel lines and running it. It may run but without tuning/jetting the carburetor to the engine, it will not work to its full potential.

While we are on this subject, there are some engines that you need to be wary of:

Late 80’s-Early 90’s 350 Chevrolets with a K engine code and an idle speed of 500 R.P.M. (TBI)
Early Ford V-8’s with the Speed Density fuel injection.
Dodge Magnum V-8’s
Any Fuel Injected application where the customer wants a loud/radical idle.


These engines/computer combinations have very special camshaft grind requirements, so should you run into one of these combinations, it would be best to call the Erson Tech Line (775/246-4062) for a recommendation.

Now I certainly do expect to reprogram the ECM.Question is if I do use a lower L/C,then do I go for a vacuum boost or trade off some of the bottom end to get a wider L/C and given a L/C is there a formula showing the differences in rpm's where the torque band starts.

The question of using a carb on this build is not a possibility.It will be a some kind of EFI.

I thought the 383's liked a longer duration/ bigger lift on the exhaust side of it.But given a towing situation/street van,it might not be significant.

The vacuum shouldn't be a issue here.TBI's systems need to keep the vac up.

Heading out to the shop to get work done.I'll look up those number cams maybe later today.

I just want to add that I am suggesting we keep mindful of the parts in this engine while building the numbers for it.Just a two cents thought I have.

Thanks guys.

Gary

As I said in post #65, you had 9.4 with 64cc heads, but you won't have 9.4 if you change chamber size. I have everything except gasket volume, which I will estimate at 9cc's.
cylinder 783.84
chamber 72
piston 18
piston deck height 0
gasket 9
Total is 882.84
Dropping out cylinder is 99
Divide 882.84 by 99 and get 8.91:1 static compression ratio. Everything is different, so be careful with your cam choice.

Richard those pistons are not 18's.They are 9.71 c/r with 64 cc heads.

Originally Posted by 1gary

Richard those pistons are not 18's.They are 9.71 c/r with 64 cc heads.

We are not concerned with what they make with 64cc heads, you don't have 64cc heads.
Gary, let us start from ground zero.

1.You are building a 383. The bore is 4.030" and the stroke is 3.75". If we multiply that out, we find: (.7854 x 4.03 x 4.03 x 3.75 x 16.387 = 783.84 cc's).

2.The heads you are currently planning to use have 72cc chambers.

3.According to the KB site, the pistons you have chosen to use have 18cc crowns....
Icon Forged Racing Pistons
This piston is an open dish design with no squish pad. Look at the illustration I linked.

4.Piston deck height is 0cc's.

5. Not knowing the head gasket you plan to use, but estimating the compressed thickness at 0.040" and the I.D. at 4.100", we can compute the cc's thusly....
(.7854 x 4.1 x 4.1 x .04 x 16.387 = 8.65cc's)

Now, we add up all the values. (783.84 + 72 + 18 + 0 + 8.65 = 882.49cc's). This is the total volume pushed into the cylinder by atmospheric pressure with the intake valve open.

Now, we add up all the values with the piston at TDC, eliminating the cylinder volume. (72 + 18 + 0 +8.65 = 98.65cc's)

Now, we divide the larger by the smaller (882.49 / 98.65) and find 8.94:1 static compression ratio.

Math is black and white Gary, there are no gray areas.