383 rebuild - old dyno results & new cam ideas

if they are solid non-embossed copper they can be cleaned and reused 5-7 times, if not REPLACEMENT is generally required

reuse after good clean-up
trash and replace
 
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I got the drivers side head off and found rust at the top of the cylinders, 3 and 5 were the worst. Still no signs of water intrusion. No evidence of leak paths on both sides of the gasket or block.

I tried rubbing the rust with an oily rag to see if any would come off. The areas are smooth but stained after. Any hope of saving it, or am I going to have to tear it down and start over?IMG_20230624_174916.jpg
 
So far the rust seems to be only on the exhaust ports in the head. The rust in the block is directly under where the exhaust valves are located.
 
could the dyno that the engine was tested on use an exhaust header that was exited into water or had water flow over it to cool the exhaust ,to mute the sound?
header reversion pulses would easily suck water into exhaust ports if a NON marine cam was used
 
The headers exited into large air vent tubes that were connected to a fan to pull the exhaust fumes out of the dyno cell. No water to mute the sound, it was loud.

I managed to pull one of the exhaust valves using my cheap manual spring compressor last night. The seat cleaned up easily with no signs of pitting. I coated the remaining valves/seats in oil to hopefully stop the rust progression. I'll borrow a pneumatic compressor from my machinist to disassemble the heads tomorrow. It took forever to get my manual to work on just the one spring.

I'm going to take the engine with me and have him look at the cylinders. Hopefully complete teardown won't be necessary.
 
pic3333.jpg
if the heads are off the engine this style valve spring compressors far easier to use

pro-66832_cp.jpg

pic4444.jpg
these also work, (below)but not as easy to use
otc-4573_w.jpg
 
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I took all my parts to my machinist to have him take a look, he also saw no signs of an internal coolant leak. I mentioned possibly running race gas on the dyno by mistake and asked if that could cause the rust issue. He said he's heard of similar issues a few times over the years from racers but has not seen or experienced the problem himself.

Fortunately, I caught it in time and the rust didn't cause any pitting in the cylinders. I was able to remove the light surface rust easily with a little Loctite naval jelly rust dissolver and a rag. I carefully, and thoroughly, rinsed the areas where applied per the instructions to neutralize the rust dissolver after use.
 
As recommended, below is a list of what was used for this refresh and cam swap along with results. I tried to be as thorough as I could, but if there is any information I may have omitted let me know and I'll do my best to add it.


-3970010 factory 2 bolt block, 2 pc rear seal
-Melling Shark Tooth Oil Pump, 10% volume increase - PN: 10552ST
-Champ Pans pickup tube, PN: 1007SB
-Champ Pans oil pan, 7 qt., PN: CP64LT
-SCAT cast crankshaft - PN: 9-350-3750-5700
-Eagle 5.7 forged H-beam rods w/ARP 7/16, 1.6" 8740 rod bolts - PN: CRS5700B3D
-Clevite H series bearings, standard size, rod PN: CB-663HN/main PN: MS-909H
-SRP forged pistons, flat top w/2 vale relief (-5 cc), PN: 138089
-JE Pistons Pro Seal Premium Sportsman Series Piston Rings - PN: S100S8-4030-5
-AFR 195 Eliminator heads: 68cc chamber (milled from 75cc), ported by local shop - INT. - 290 cfm@.550, 293 cfm @.600/EXH. 219 cfm@.550 and 222 cfm@.600, upgraded AFR HR valve springs: 1.29 O.D - 155 lbs@1.810, 412 lbs @1.21, 428 lb. rate
-Bullet hyd. roller cam, steel core:
grind #: CHS 299/304-08HR
240 in/245 ex @ .050
lift .570 in/.570 ex
108 LSA
-CLOYES Street True double roller timing chain, PN: 9-1145
-COMP roller thrust button, 0.680" length, PN: 211
-Isky Silver Series HPX Hydraulic Roller Lifters - PN 2077HYRT
-COMP Cams Hi-Tech Pushrods, 7.500" length - PN 7957-16
-COMP Cams Ultra Gold Aluminum Rocker Arms (older body style), PN: 19001-16
-Edelbrock performer RPM air gap intake, unported, PN: 7501
-Proform High Flow Mechanical Water Pump, Aluminum, PN: 67265
-MSD Pro Billet Distributor w/vacuum advance, PN: 8361
-Comp Cam Melonized distributor gear, PN: 410M
-AED Birchwood carb spacer, open 1", PN: 6170
-Holley 750 DP

-Fel-pro head gasket, 4.166 bore / .041 compressed, PN: 1003
-Fel-Pro Intake Manifold Gasket, PN: 1205
-Fel-Pro Oil Pan Gasket, PN: 1803
-Fel-Pro Rear Main Seal, PN: 2900

-ARP High Performance Series Cylinder Head Bolt Kit, PN: 134-7303
-ARP High Performance Series Main Bolts, PN: 134-5001
-COMP Cams Cam Lock Plate, PN: 4605
-ARP Oil Pan Bolt Kit, PN: 434-1803

Main Bearing Clearances:
1 - .0024
2 - .0026
3 - .0025
4 - .0026
5 - .0026

Rod Bearing Clearances:
1 - .0025
2 - .0025
3 - .0024
4 - .0025
5 - .0025
6 - .0024
7 - .0025
8 - .0024

Rod side clearance - .018
Top piston ring gap - .020
Second piston ring gap - .022
Crank end play - .008
Cam end play - .006
Piston to valve clearance:
Intake - .156
Exhaust - .139

Dyno results:
Dyno Results.jpg

Cam card:
cam card.jpg
 
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