383 building advice

[Indycars]

Thank for your all good inputs Rick and Grumpy, much appreciated .
I have used some hours this weekend looking through Ricks thread about his engine
building, and I must say it is very impressive and packed with good information for
someone like myself trying to put together a engine without a lot of experience and
knowledge. I think I will need to use the thread as a guideline and reference for my
engine built up. From what I could see and understand you are happy with the cam
selection and the car and I will consider using the same for my engine.

You are the exact type of person I did all the work photographing and posting to
help and I wanted to HELP Grumpy and his forum. I could have finished my engine
at least a couple of months earlier, but it takes time to take photos, annotate
them, develop text and then post it all.

Nothing compared to the time Grumpy put into this forum !!!

So Many, Many Thanks for Your Comments, it makes the time I took all worth
the effort !

Now I don't want poop on your parade, but it might be the best money you ever
spent ...... Have You Had the Cylinder Wall Sonic Tested for Thickness ???

You should read this thread where Grumpy put the most feared three words
in engine building in my EAR ...... Have you sonic tested your block for
"Cylinder Wall Thickness" ??? Believe me I know how painful it can be. I had
spent a $100 in abrasives and 30 hours of vibrating labor to smooth the
outside of the block and then I did it all over again on the new Brodix SHP block.

Read this thread and see what you think.

viewtopic.php?f=51&t=3169&p=8487&hilit=should+have+purchased+a+Dart+SHP+block#p8487

 

[cornor]

Rick, the block I have is suppose to be a new block initally bored .030, and hardly used. The unfortunate was that the previous owner had the engine sitting outside for a while and when I opened the engine to check, I found corronsion on a couple of cylinder walls, and I had the machine shop machine it another .010, so it is now 4.040 dia. My machine shop stated that .040 was not a problem and the block was good, but I will check if they can do a sonic test, but I not sure the have the equipment to do this. I have allready purchased the new 4.040 pistons and rings, so I hope it is OK. It is anyhow a good advice to check this before I go futher. Thanks

 

[cornor]

Hello again, while I am waiting for the block to be checked and hopefully be confirmed OK I am looking into the cam selection.
I think I would like to go for the hydraulic roller Crower 00471 cam recommended, and which I understand is the same that Rick have in his engine.
From what I can calculate and see this will give me around 8 in dynamic compression as per Grumpys recommendation, and a overlap of 69deg. which should be OK for a hot street engine if I have this correctly. Will my 1.6 roller rockers (PEP) work OK with this set up or should I aim for something else ?
Rick how is your experience with this cam in your engine, now after you have driven it for a while ?. I see that you are doing a lot of tuning and work with your carb now, but I assume you have been driving the car also, I saw the videos from the drag race, and that was nice.

Would a dual plane intake as the airgap RPM be a good choice on my engine ?

I will keep you posted when I have more info. It will take some time to get the needed parts from US. Even with airfreight which can be used for not too heavy parts, it will take around 2 weeks to get parts. We have some decent US car part shops here, but if you shall have something a bit special, you will need to get it from US.

Regards

Pal

 

[philly]

a two plane intake divides the engine so that the runners joined to either half of a 4 barrel carb draw 180* apart.... its principle advantage is that there is no overlap of induction cycles; the interaction of one induction stroke on the next and its negative impact on idle and cruise vacuum , is negated. the downside is the runners must follow a more tortuous route from the carb to the intake port and the effective carb flow as seen by any cylinder is halved.

basically a dual plane intake (and the rpm air gap is probably the best of these off the shelf) is very much suited to street driving and performance while the single plane (and tunnel ram) intakes forego some of the street convenience to give you higher rpm power potential.

ive never run a single plane intake and have never caught myself saying "oh damn i wish i had a single plane for more power." but then again, it has to fit your combination.

 

[philly]

based on the selection of the crower cam 00471 and the suggested redline of 6400rpm by crower, i would say you probably will make more power and torque and have better driveability in your intended rpm range with the dual plane setup and again the rpm air gap is probably the best off the shelf duel plane intake for small block chevies

 

[Strictly Attitude]

I would have ran a roller too but would have been solid roller if it was in my budget. Which it wasn't due to other upgrades I made at the time that added up very quickly. You will need to replace the springs on your heads to the recommended spec. I would get a complete kit if possible.

 

[Indycars]

Hello again, while I am waiting for the block to be checked and hopefully be confirmed
OK I am looking into the cam selection.

Even stock bore blocks can have marginal cylinder wall thickenss, when exceeding
500 HP in a SBC. Look at my numbers and subtract .030 inches from the numbers
and you will see what I refer to.


I think I would like to go for the hydraulic roller Crower 00471 cam recommended,
and which I understand is the same that Rick have in his engine. From what I can
calculate and see this will give me around 8 in dynamic compression as per Grumpys
recommendation, and a overlap of 69deg. which should be OK for a
hot street engine if I have this correctly.

Pal ….. please post the numbers you are using for your Dynamic Compression Ratio (DCR)
and be specific and detailed.

Yes the Crower has 69 degrees of overlap, that’s ground into the camshaft and can’t
be changed during installation. Only a new camshaft will change overlap.

It’s easy if you are close to the correct DCR to tweak it by adjusting the Intake Valve
Closing (IVC) angle. Check out the differences below in the graphic. Keep in mind that
you are giving up about 200-300 RPM in the low rpm torque. I wish now that I had used
the 2 degree retarded position, numbers in the yellow middle column. Keep in mind
that the gas I'm using is 91 octane [(R+M)/2], that's the best available pump gas here
in Oklahoma, USA.

viewtopic.php?f=99&t=4458



Yes I'm using the Crower 00471 Crower and I love it, but I only weigh about 1800 lbs
and using an 200-4R automatic trans, but you have the M22 manual trans and clutch
that will compensate for the heavier car. I also have a very tall tire at 31 inches. I
went from 28 to 31 and that pretty much like going from 3.7 to a 3.5 rear gear ratio.
Not making a big point above, but it is background that applies to this post and our
situations being compared.


Will my 1.6 roller rockers (PEP) work OK with this set up or should I aim for something
else ?

Should work fine, but you will need to measure your “valve to piston clearance”. That’s
true not matter what camshaft you run. Not sure what size rocker studs you are running,
but 3/8 inch will definitely benefit from a girdle. Hopefully you have 7/16 inch studs,
again a girdle can’t hurt. I’m using 7/16 studs and no girdle, time will tell. I don’t expect
them to break, but there is more to it that NOT breaking, it’s called better valve train
control. Money sometimes dictates the decision.


Rick how is your experience with this cam in your engine, now after you have driven it
for a while ?. I see that you are doing a lot of tuning and work with your carb now, but
I assume you have been driving the car also, I saw the videos from the drag race, and
that was nice.

No better way to explain than an example. Some guy was taking pictures of my car at
the stoplight, I was in the turn lane. The turn lane leaves first here, so I blipped the throttle
(@1800 RPM) about 15 feet into the turn and the back of the car raised, the tires break
loose momentarily and then it settles to make the turn. Do I like this camshaft …..
HELLLLLL YESSSSS!!!!


Would a dual plane intake as the airgap RPM be a good choice on my engine ?

Yes it’s going to be your best option for your situation. Now if you were street racing for
money and ¼ miles times were in the 10’s, then a single plane might be in your future with
a higher revving camshaft. The only thing that matters is winning the race and getting to
work doesn’t matter or doesn’t apply.



I will keep you posted when I have more info. It will take some time to get the needed parts
from US. Even with airfreight which can be used for not too heavy parts, it will take around
2 weeks to get parts. We have some decent US car part shops here, but if you shall have
something a bit special, you will need to get it from US.

Keep in mind that there are different materials that you can purchase when buying a
camshaft. So every camshaft has several versions of the same grind, just difference
materials and different distributor gears. You will have to make sure that the cam gear
and distributor gear are compatible or it will ruin the cam gear and therefore the camshaft.
Grumpy will be able to post some good info for you or just do some research here.


Regards

Pal

 

[Strictly Attitude]

Don't forget a bronze distributor gear, a cam button, thrust bearing, and an aluminum timing cover I was going to use the cloyes cover with the built in cam button. That is why I did not go roller over solid there is allot of cost. You will also need a good set of pushrods for that cam. Not trying to discourage but make sure you get everything you need especially with a 2 week wait time.

 

[philly]

i know you are already overloaded with information and reading material however rick created the single best guide for this procedure ive encountered on the internet... with many pictures! port matching intake manifolds to cylinder heads:

viewtopic.php?f=55&t=5378&p=32456&hilit=port+matching+intake+manifold#p32456

viewtopic.php?f=69&t=3814

 

[Indycars]

Thanks you Sir Phil for the nice comment ...... you were Knighted by the Queen of England ???

 

[philly]

the queen of england may be old, but like all older ladies she still has her secret ways

 

[Indycars]

the queen of england may be old, but like all older ladies she still has her secret ways

I just had a very scary visualization! It's going to take awhile to get that out of my head!

Now back to the task at hand here, good performance.
-----------------------------------------------------------------------------------
Conor,

Thought you might find the two simulation runs that I did for the Crower 00471
and the CompCams XE294. I'm still wondering if I made a mistake, but I did
spend 1/2 hour to just proof the numbers I used for both camshafts.

The CompCams sometimes does not add up exactly. They state the exhaust
duration to be 306°, if you check their numbers it's 305°, Intake is 293
Exh Dur = 41° + 180° + 84° = 305°
Int Dur. = 39° + 180° + 74° = 293°

I made a couple assumptions.
1.) Deck Clearance: ............020 inches
2.) Head Gasket Thickness: ...020 inches
Therefore Quench Distance: ...040 Inches
Static CR: 10.03




I invite you to proof the 8 page report on the Crower 00471 engine below to make
sure the numbers used are correct. Any other camshafts you want to see?

 

[Indycars]

Below is the Cam Manager window. Using the 1.6 rockers add a tiny bit of
duration to the Crower 00471 camshaft.

 

[cornor]

Hello again, and thank you and for taking the time to guide me and advice me . I am trying to absorb and learn, but obviously have a way to go .
Thank you Phil for pointing me to Rick excellent instruction on port matching, I read through this when I read the engine tread, which I general is packed with very good and useful information for a guy like me with limited knowledge and experience with engine building. I will use the airgap intake, and try to port match it as per the good guideline I have from Rick

Here is the calculation I did, I also tried the same with the compression calculation sheet you have Rick, but was a bit uncertain on some input, so I used this one from United Engine & Machine who make the Icon pistons. I could possible use a thinner head gasket 0.015 maybe and raise the compression 0,5, but I already have the felpro 1003 gaskets which AFR recommend and they are 0,041 thick.

I have 7/16" studs; and I will consider if it is worth taking any risk with unknown brand rockers.

John, The springs I have is the AFR- PAC Racing Spring 1.290" OD Hydraulic Roller Dual Valve Spring,
140 lbs on seat, .600" maximum lift, Max RPM 6300-6800 which came with the heads. I understand that I might have to change these.

Thank you for the very interesting and detailed report on the on the engine with the Crower cam, Rick, I will spend some time reviewing this, but from what I can see I like the torque and power curves and the numbers that this indicated.

I have the engine at the machine shop now, and waiting for the 4.040 pistons which has been ordered, then I will decide if bring the engine home and work on putting it together myself or get the shop to put together the long block, and the assemble the cam and head myself at my home.

I am preparing to take out the other engine from the corvette now, to clean up the engine bay, and make everything nice to put in a new engine. I am calculation the number to see if I can afford to put in a Tremec 5 speed at the same time, but cost keep adding up, with new cam, intake +++, so I will have to see.

I will keep you posted and possible add some pictures when I get things going.

Thanks again all of you for great input and support.

Regards Pal ( it is actually Pål which would be pronounce Paul) But we have a special Norwegian letter "å"

 

[Indycars]

( 1 ) Here is the calculation I did, I also tried the same with the
compression calculation sheet you have Rick, but was a bit uncertain on some input,
so I used this one from United Engine & Machine who make the Icon pistons.

( 2 ) I could possible use a thinner head gasket 0.015 maybe and
raise the compression 0,5, but I already have the felpro 1003 gaskets which AFR
recommend and they are 0,041 thick.

( 3 ) Thank you for the very interesting and detailed report on the
on the engine with the Crower cam, Rick, I will spend some time reviewing this, but
from what I can see I like the torque and power curves and the numbers that this indicated.

( 4 ) I have the engine at the machine shop now, and waiting for
the 4.040 pistons which has been ordered, then I will decide if bring the engine home
and work on putting it together myself or get the shop to put together the long block,
and the assemble the cam and head myself at my home.

Regards Pal ( it is actually Pål which would be pronounce Paul) But we have a special
Norwegian letter "å"

1) The DCR you calculated is correct according to the United Engine's instructions,
but the estimated IVC is off by quit abit. It's always better to use real number when
you have them. The cam card tells you that the intake valve closes at 69° ABDC.
This number must be the seat timing number and not at .050 inches. Now when we
use the correct timing number you get a much lower DCR with the 10° later IVC angle.

I bet the numbers that you were confused about were the two numbers, "Top Ring Height"
and "Ring Land to Cyl Bore Clearance". They make very little difference and can be
ignored if you don't know them, the numbers I used should be close enough. If you check
out the "Compression Ring Volume" on the page 3 (Intermediate Calc) you will see that
it only amounts to .25 CC's. Technically, it's all part of the combustion chamber volume.
It's just me, I like to calculate down to the Nat's Ass.

Somehow you need to reduce to combustion chamber volume by about 5 CC's, then you
will have a DCR of ~~ 8.0




2) NO, please don't do that!!!

Your quench distance will be much too low at .001 + .015 = .016 inches. This needs to
be in the .038 to .045 range, preferably .040-.042 inches.



3) You are very welcome, but remember ...... that the OUTPUT numbers are no good
until YOU confirm that the INPUT numbers are correct !!!!!!!!

4) Please bring it home, your expenses at the machine will be much higher if you have
them do ALL THE REQUIRED CHECKS, plus assemble it. Doing it yourself will bring a
great deal of satisfaction for yourself. We love helping here on this forum and like to
think we have the friendliest people.

Hey thanks for the heads up about your name and pronunciation! That makes more
sense now.

 

[cornor]

Rick, thanks again for good input. I though I had the DCR close too 8, but obviously the calculation used was not accurate enough. Will 7.7 visa 8 make a big difference for the performance of the engine ?. If so I will have to consider my options. From AFR web page they inform that milling 0.006 will reduce volume approx 1cc, so I could mill off around 0.030" to reduce 5cc and obtain 70cc combustion cambers. Alternatively If I used another cam which have a lower intake valve closing angle that would also raise the DCR, if I get this right. I tried put in numbers for a cam from Lunati specked by David Vizard in his book " David Vizard's How to Build Max Performance Chevy Small Blocks on a Budget" advertised duration 282/282 and 231/231 deg at .0.050 and LSA 106 it will come out quite good on the DCR, but I do not know if that could be a option which will give me a good result without modifying the heads , or will I be loosing a lot of power with such a set up ?. I see Vizard advice a LSA like 106 for a 383 but I am not sure if this will have big impact on idle quality, he state that as long as the overlap is not too much you should not have problems. I have added the info from the book about the cam into your comp calc. spreadsheet i get:

Advertised Duration: 282 / 282
with Total Cam Adv: 4
LSA/ICL 106/102

Intake Open BTDC: 39
Intake Close ABDC: 63
Exhaust Open BBDC: 71
Exhaust Close ATDC: 31
Overlap: 70

Any suggestion on which way to go, mill down the head (to get DCR of 8) or leave as is, or possible change cam and keep the rest of my set up as is ? Please excuse me if I ask a lot of stupid questions, but I am not a experienced engine builder, and just trying to learn and avoid doing mistakes as I plan and move forward with my building. Ideally it may have been better to start from scratch, but as I already have a lot of parts available, I would like to use they if suitable. Thank you for your help and patients with me.

Regards
Pal

 

[grumpyvette]

I'd suggest you don,t mill the heads as its potentially going to add far more problems that it cures.
ideally youll want a fairly tight LSA of close to 106 in a cam for a 383, but the difference between a 106-to a- 110 LSA,is not going to make or brake the combo, it simply changes the volumetric efficiency slightly and its only ONE of dozens of factors that will effect your results.
going with a slightly wider LSA tends to broaden the power band and smooth out the idle SLIGHTLY but the difference is not huge on cams with the same lift and duration.
yes the more factors that you calculate and take the time to maximize the better, but don,t think that one change will destroy the engines power curve.
I tried the CROWER 00471 in my cars 383 and then settled on the CRANE 119661, there was no question the crower 00471 made better peak power, than the crane 119661 , but being a bit older and less impressed with "POWER" than over all day to day drive-ability, and having installed a 200 hp wet nitrous system on that car that provided more than enough EXTRA kick when I needed it I felt I could compromise and loose a few PEAK N/A hp with ZERO NET LOSS
every choice you make is a compromise in some area!, ID strongly suggest you talk to at least 5 cam manufacturers and get their opinions on what cam to use, in YOUR application, then take that info, average the results in LSA,LIFT AND DURATION, and BUY the cam that best matches that AVERAGE and NEVER discuss with any cam manufacturer what a different supplier might have recommended, simply, give them all the factors in the engine and drive train and let them make a choice, if you relate what others have said your skuew the results, and in most cases guys seem to want larger cam duration that the engines ideal cam might have, remember insisting on bigger,or longer spec, in a cam duration, is rarely going to result in a better, running engine ,in a street car cam selection, once you get into the correct ball park in lift and duration.

Verifying your engines clearances, and rocker geometry, and use of A rocker stud girdle and high quality roller rockers go a long way towards maintaining valve train durability

first CHEVK CLEARANCES AND GEOMETRY

the higher rocker ratio increases the effective acceleration rate of the cams lobe ramp, being transmitted to the valve so the higher ratio tends to cause valve control issues at a lower rpm level UNLESS the valve spring load rates increased to compensate. this allows a greater area of lift or open port area so the engine will tend to run better in the mid rpm range, generally making it well worth while as the mile duration cam can use the extra lift and duration at the valve.

btw, if you've ever had to stop a project because you could not locate the required matching bolt, or fastener, to install a bracket or accessory or engine component ,
you know how frustrating it will be to have to stop and locate the required fastener or go to a local hardware store and hope they have the required bolt.
and yes theres a great many sizes and types that are rather unique to automotive use and some specific to brands, and models.
now obviously you can spend a small fortune buying a vast assortment for your shops use.
or you can grab a 5 gallon bucket and a small assortment of ratchets wrenches and sockets ,
and visit your local salvage yard and grab some accessory or component you need and in the process,
you can remove and save, and throw several hands full of assorted fasteners in the bucket , on every trip to the salvage yard when your purchasing used re-buildable major components

to re-stock your shops bolt box.
most salvage yards don,t mind this approach IF YOUR BUYING SEVERAL COMPONENTS in the process,
like all the parts and brackets off an engine , a set of cylinder heads, a power steering pump, or intake manifold for example or the disc brakes
most will NOT allow you to simply start pulling a large selection of fasteners , without a significant component purchase, or two too cover the cost of those fasteners.

http://garage.grumpysperformance.com/index.php?threads/fastener-storage-idea.3898/#post-10324

http://garage.grumpysperformance.co...spare-bolts-and-assorted-spare-parts-in.3557/
RELATED INFO
viewtopic.php?f=52&t=727

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viewtopic.php?f=32&t=430

 

[Indycars]

Taking off .030 inches is a lot for the sake of reducing chamber size. It would
tend to reduce the clamping for between the head bolts by reducing the strength
of the head. That's not to say it wouldn't work, but the chances of getting into
trouble are little greater.

Look, you don't need to apologize for your questions!!! We love to help and encourage
all questions, it gives us old guys something to do. As long as you are learning and
not making the SAME mistakes twice, then you should be proud of your progress!!!

If you can be happy with the engine you finally build, then by all means use the parts
you have. But it's best to start over, if you are going to spend lots of money and
time and get to the end and be disappointed with the results.

 

[cornor]

Hello again, Been busy with work, but have checked around for alternative cams
I got a proposal from Crane for a #119701 HR cam. I also got some info from
Jones Cam who proposed

Cam# SBCR, HR70340-71340-108
224/228 @ .050"
.340"/.340" Lobe Lift
.544"/.544" Valve Lift
108 LSA

Duration Lobe Net Lifts
Part # @ .006″ @ .050″ @ .200″ Lift 1.5 1.6 1.7
EHR70340 272° 224° 147° .340″ .510″ .544″ .578″
EHR71340 276° 228° 151° .340″ .510″ .544″ .578″

I don't know how these would work in my engine, but the Jones cam came out with exactly 8 in DCR when I put in the no. in the calculation.
Both of these cams have lower duration and lift than the Crower and Crane 119661, so I assume this give give me less power up top but possible some better torque down low ?.
Jones decribe the cam "This cam was designed to make peak HP at 5,500, and will make great low-end and mid-range power. It'll also hold the power past 6,000rpm." estimated power level 450-500hp.

I have sent inquiries to some other companies like Crower, Lunati, Comp Cam and Isky- but they have not replied.

Any comment on these cams ? Do you think they would be worth considering ?

 

[Indycars]

Looks like this is one of those Crane cams with a Asymmetrical Lobe profiles. They
like to accelerate the valve open faster than they decelerate it closed, which helps
keeps the valve from bouncing off the seat when it closes. So you can't make the
usual calculations like you can with a symmetrical lobe. Crane has to give you the
numbers.

The Hydraulic Intensity (HI) 48 of the Jones cam shows a cam that open/closes the
valve faster and give better performance by creating more area under the curve.
BUT it will be harder on the valve train when compared to the Crane HI of 66 cam.
I don't know what is an acceptable HI number for the street, hopefully Grumpy will
speak up on this matter.

The graphic below show the difference in different types of camshafts, but the
concept is the same ...... more area under the curve means better performance.



Because of the asymmetrical lobe, I can't tell you if the cam is installed straight up
or 4° advance etc. If my numbers are correct, then the Crane is going to have a
cranking pressure that is too low to provide good torque at low RPM.