84 CFI 383 suggestions

Gibbles

Gibbles

Clicker of buttons
Well my 84 vette has been kicking some ass with the renegade intake, edlebrock heads, headers, 3in exhaust system, and those flowmaster 40's w/dual xpipes sound like sex... :D

However that copper head gasket has been leaking exhaust into my cooling system it seems...
It's pretty sensitive to how hot the car is.
I guess when the manufacturer says it must be installed with stainless o-rings, they meant it. :rolleyes:

Anyways, the heads need to come off so i can go over everything, and i decided if i need to go that far, I'm pulling the engine.

And if i'm pulling the engine, then i might as well rebuild it.
And if i'm rebuilding the engine, then i might as well stroke the thing. ;)

Issue i'm running into, with my current camshaft, and 70cc chamber edlebrock heads, I'm getting some pretty high DCR (830).
Pistons with the largest valve reliefs that are also forged, are still only 6.4cc.

Thinking a different camshaft might help... Or i see if a machine shop can open my chambers up a little to get the DCR down a bit...

Thoughts?
 
without me going back and looking,
please remind me of the details on your current engine combo,

BTW THATS VERY IMPRESSIVE THE DETAILS YOU INCLUDED ONCE I LOCATED THE INFO, THANK YOU:D:thumbsup:

I'm sure you can copy & paste that info etc
I FOUND IT!
Car = 1984 Corvette with Z51 package

Intake = renegade crossfire: ems-msren-100p http://www.summitracing.com/parts/ems-msren-100p
Intake bolts = ARP 12pt: http://www.summitracing.com/parts/arp-134-2101
Camshaft = Crane 114132: http://www.summitracing.com/parts/crn-114132
Camshaft lock plate: http://www.summitracing.com/parts/crn-99168-1
Rocker Arms: Scorpion 1.65 ratio http://www.summitracing.com/parts/scc-scp1008 (to give total lift just shy of .500)
Head gasket = SCE copper .021 thickness: http://www.summitracing.com/parts/sce-p11062/overview/
Timing chain = Compcams magnum double roller: http://www.summitracing.com/parts/cca-2100
Head bolt set = ARP 12pt: http://www.summitracing.com/parts/arp-134-3701
harmonic balancer = Summit Pro Street 6.750in: http://www.summitracing.com/parts/sum-161350
harmonic balancer bolt = ARP 12pt: http://www.summitracing.com/parts/arp-134-2501
Valve covers = Edlebrock Signature series: http://www.summitracing.com/parts/edl-4449
Heads = Edlebrock EStreet 70cc pn 5073: http://www.summitracing.com/parts/EDL-5073/
PushRods: http://www.summitracing.com/parts/sum-g6400100 (Adjustable pushrod was key here)
Headers = Melrose brand with ceramic coating option, came as a package with 3in exhaust: http://www.melrosecorvette.com/1984-1985-l98-corvette-header-system/
Header gasket = Felpro 1406 http://www.summitracing.com/parts/fel-1406 (they matched up with the edlebrock ports perfectly)
Mufflers = FlowMaster 40: http://www.summitracing.com/parts/flo-80430402
Sparkplugs = Champion RC12YC http://www.summitracing.com/parts/cpn-711
Ignition Module: http://www.summitracing.com/parts/dui-000333 (not installed yet)
crossfire balancing info: http://www.thecubestudio.com/CrossfireThrottleBodyBalancing.htm
Transmission: Modified 700r4
Converter: FTI 2400 RPM stall (PN FTI-SB2400LT30) https://www.summitracing.com/parts/fti-sb2400lt30
Transmission TV cable: (PN25-257505-1) special for 1984 http://www.ecklerscorvette.com/corv...t-cable-automatic-transmission-1982-1984.html
TV info: http://www.tvmadeez.com/article/

Rear end ratio = 3.07 ratio D36

Shocks = Bilstein "Sport" (correct for z51; installed on the rear, pending on the front)

Transmission info
ShiftKit = Transgo 700-2-3 PN TRG-700-2-3: https://www.summitracing.com/parts/trg-700-2-3
Seperator plate = transgo heavy duty PN 700-P: https://www.summitracing.com/parts/trg-700-p
Sonnax check balls PN 10000-08: https://www.summitracing.com/parts/sox-10000-08
Sonnax Input Drum Reinforcement Kits PN 77733-51K: https://www.summitracing.com/parts/sox-77733-51k
Sonnax wide sungear bushing PN 7701001
also requires upgrade to newer style bonded pistons, drop in parts to older input drum: PN 24205273 24200290 24205272 24206085
Sonnax Servo Pin PN 77787-02K: https://www.summitracing.com/parts/sox-77787-02k
2-4 band = Alto red eagle wide band: PN 57961
Sonnax 4th Gear Super Hold Dual Servo PN 77767K: https://www.summitracing.com/parts/sox-77767k
For front and rear planets used GM 5 pinions and carriers
Front and rear sprags, upgraded from later 4l60e (requires full assy to upgrade sprags)
Transmission clutches: Alto Red eagle
Transmission steels: Kolene steels

Transmission pump upgrades
Upgrade from 7 vane to 10 vane
Transgo hardended high RPM pump rings PN 700-PKH: https://www.summitracing.com/parts/trg-700-pkh
Transgo Forward boost valve PN TRG-7-500: https://www.summitracing.com/parts/trg-7-500
Transgo Low/Reverse boost valve PN 7-300: https://www.summitracing.com/parts/trg-7-300

Last edited: Jun 23, 2016
Click to expand...






Ive never yet seen properly installed copper head gaskets leak,
(even without the stainless o-rings)
but theres always that potential with any head gasket
if the head gasket leaked be sure the machine shop checks,
the current heads and block surfaces carefully for damage.
you might want to do the math before selecting a new cam,
if you do want to stroke that engine from a 350,
to a 383 because the new rotating assembly will require new dished pistons
once you get the new static compression we can select the correct matching cam,
increased displacement from 350 to 383 even if everything else were to stay nearly,
identical, generally results in a 40 -50 ft lb over most of the rpm range and 40-50 hp boost

ideally you'll want to find a 383 sbc with the 350 main journal diameter to fit the 350 block, rotating assembly with a dished pistons
(forged is ideal but hyper-eutectic would work)
and internally balanced rotating assembly with 7/16" rod bolts,
5.7" connecting rods ,( cast steel crank would work,
but obviously forged steel is even better, in that its significantly stronger and more durable)
that rotating assembly should have about 9.5:1 static compression

RELATED INFO

http://www.scatcrankshafts.com/rotating-assembies/rotating-assembly-product-search/

http://garage.grumpysperformance.com/index.php?threads/383-information-overload.11137/

http://garage.grumpysperformance.co...383-build-that-is-now-going-to-be-a-400.7804/

http://garage.grumpysperformance.com/index.php?threads/bits-of-383-info.38/

http://garage.grumpysperformance.com/index.php?threads/tips-on-building-a-383-sbc-stroker.428/

http://garage.grumpysperformance.co...ing-a-383-sbc-combo-planing.12168/#post-71932

http://garage.grumpysperformance.com/index.php?threads/finding-a-machine-shop.321/

http://garage.grumpysperformance.com/index.php?threads/another-383-build.12786/page-3#post-66155

http://garage.grumpysperformance.com/index.php?threads/is-this-the-right-383-combination.12164/

http://garage.grumpysperformance.com/index.php?threads/crossfire-sleeper.12732/
 
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Originally i failed to go back and re torque the heads after engine breakin, then i had a massive overheat on the hottest day of the year.

I likely lost the copper sealing spray, as it sits now, i'm still driving the car, i just keep an eye on the coolant level.
Weirdest part is i only seem to notice issues when it's over 100f outside.

I finally figured it out this summer, started having issues again, and i noticed pressure in the system after it had been sitting over night.
Also seems to be very load sensitive, harder i drive the car, the more coolant goes into the overflow.

When it's apart again, i'll have a machine shop give the engine and the heads a good looking over.

And i have the compression calculator filled out, but the sheet is at work detailing my options.
What i found, if i could find a good forged piston that has a 7 or 7.5 dish, or valve relief, it would be perfect.

Or i gain a few cc's in the cylinder heads chamber via a skilled machinist...

I'll post the calculator results monday...

I also have a spare set of CFI throttle bodies i'm going to have bored to 2in as well...
 
Also an addition to the build info, i now have an FTI ESRL 9.5in 3200 (or was it 3400) RPM torque converter, and a billet pump rotor.

It made the engine VERY responsive, revs super fast, and i seem to be addicted to laying rubber patches...

Makes me giggle every time... :D

I have been very happy with that torque converter. :cool:
 
yes I have to admit that when I personally swapped from a stock stall speed converter
,in my 383 sbc corvette and installed a 3200 rpm stall speed converter the difference in performance was amazingly better.
swap too a 3.73:1 rear gear and you've noticeably further enhanced that seat of the pants and slam in the back acceleration.
people tend to not fully appreciate the fact that the performance cars drive train gearing, power to weight ratio and the converter stall
(in the case of automatic transmission) must match the engine torque curve if the car is to perform to anything close to its best potential.
 
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I believe i have a 3.07 rear end (or really close to that), with the 18in C5 rear wheels my gear ratio is quite steep.
I spent some time with a gearing calculator vs RPM, and it was amazing how fast i can get up to in first and second gear.
If i recall, third gear can do 160mph...

It's made high RPM AE fuel map learning very painful since i need a good solid load while in WOT.
I have found a few very steep canyon roads where there is not much traffic that have allowed me to get some read while in second gear, however i still need to be going at a pretty good clip to get a read over 5k rpm.
 
I never could get my copper head gaskets to seal either. So you are not alone in this.
Same brand as yours, SCE, and also like yours, no sealant beads around each water port.

An extra 1 to 1.5 cc's would drop your 350's DCR down to an acceptable level, but I think you
are forgetting that the extra stroke will raise the DCR way beyond the 8.3 you now have.
Your new pistons should need something like 15cc's (IIRC) to get you into the 8.0 range with
the longer stroke crank.
 
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Here is the calculator filled out.
Description labeled as "383 stroker" or "Engine 4"
 

Attachments

  • Compression calc filled out.xlsx
    25.2 KB · Views: 5
Grumpy; I uploaded to the site, I verified it's working on my end...
Are you getting an error?
possible I need to adjust something (depending on the error), I do have a software push that tries to secure everything...
 
Loves302Chevy said:
I never could get my copper head gaskets to seal either. So you are not alone in this.
Same brand as yours, SCE, and also like yours, no sealant beads around each water port.

An extra 1 to 1.5 cc's would drop your 350's DCR down to an acceptable level, but I think you
are forgetting that the extra stroke will raise the DCR way beyond the 8.3 you now have.
Your new pistons should need something like 15cc's (IIRC) to get you into the 8.0 range with
the longer stroke crank.
Click to expand...

That might expand my piston options, maybe I missed something in the calculator... :)
 
Ok trying again, saving as an older version of excel...
 

Attachments

  • Compression calc filled out_2.xls
    56 KB · Views: 6
upload_2018a.png
 
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because your going to buy a rotating assembly for the 383 you may want too look into using a dished piston to get the static compression low enough to get the dynamic compression a bit lower , or select a cam with a bit longer duration, like a crane 119661
 
hard part I'm finding, piston dish is so large it drops my static and DCR below what I have now.
I see a bit of a better options using the Hypereutectic, however I'm still playing with my timing and fueling.
I like the peace of mind of having a forged piston..

Maybe if I change the valve timing to delay the intake closing?
I will still be at a 10.02 static CR, but I can get that dynamic compression down.

I'm also running a 160 degree thermostat, and I have a rather large radiator.
When I have coolant in the upper part of the engine (lol), it stays a pretty steady under 200 degrees, with AC on and in traffic in the hottest part of the summer, it never goes over 210.
I suspect it will get much better once I fix the head gasket issue once and for all...

I also saw that Wiseco will do custom pistons... I have noidea about the cost involved there.
 
install the cam at split overlap (STRAIT UP) and do the static and dynamic calcs
several times
then, you obviously could call a few piston manufacturers of your choice ,
and discuss cost and options , and delivery times
 
Lots of reading to still do, I'm planning on executing this plan this summer when it's too hot to drive the car once again...

Original plan was to do it over this winter, however I'm still paying off a new air compressor (Quincy QT54), and a rather elaborate air system I setup with painting a car in mind...
I burnt up two smaller air compressors, I decided it was time to stop goofing off... ;)

Then over Christmas there was a good sale on a decent toolbox... right about that time I decided I could no longer stand my current tiny toolbox...
That officially pushed this project back. :D

Now my garage looks like I might know what I'm doing, however you and I know otherwise... :rolleyes:
 
I think most of us have run into a great many similar choices, between buying tools and auto parts,
its simply the result of a limited budget ,in most cases,
and most of us make a few mistakes ,
but as long as you keep the goal of building the car in mind you'll do ok.
after you gain experience there's both engineering and art involved in the process,
you'll generally start with a goal, you've envisioned for your car, reality and physics will provide some of the limitations, you'll be limited to a budget and at times by your access too tools and limited by your skills and knowledge, youll generally start,by simply making a very detailed list of the components you want too use ,to upgrade and modify the car to gain the performance and look of the car, and once you have that list of components, and being forced by going back through that detailed, list and doing the required math too verify you have selected the correct matching parts, and when you find you have to change a few components you go back, change the list and again revue the math, most of us start out without the required knowledge to accurately match parts and your goal.
yet this process forces you to do some research into what you can reasonably accomplish with the tools and skills you have and the realization that you may need to acquire both skills and more tools as you proceed.
 
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