first hotrod build

hotrod coupe said:
basic dynamic c/r for 89 octane would be appreciated
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From Brian R:
It's Best to test your Cranking Cylinder pressure .
Use a Good engine compression guage.
I have a Snap On. But any brand will work.
160-165 psi is 87 octane.
175-185 is 91 octane.
190-195 is 93 octane.
I got these numbers from old Vintage Hotrod articles 1999-2003 online.
I had to Dig Deep.

195-210 is really pushing it on 93 octane.
Must use every Trick...EFI Territory .
And likely unable to run full ignition advance 28-39 degrees BTDC.

from others:
For a typical carburetor equipped engine, without engine management [27,38]:-
Compression Octane Number Brake Thermal Efficiency
Ratio Requirement ( Full Throttle )
5:1 72 -
6:1 81 25 %
7:1 87 28 %
8:1 92 30 %
9:1 96 32 %
10:1 100 33 %
11:1 104 34 %
12:1 108 35 %

Modern engines have improved significantly on this, and the changing fuel specifications and engine design should see more improvements, but significant gains may have to await improved engine materials and fuels.

Based on this information I extrapolated the following expansion of the octane chart

DCR Octane #
7.1 87.5
7.2 88.0
7.3 88.5
7.4 89.0
7.5 89.5
7.6 90.0
7.7 90.5
7.8 91.0
7.9 91.5
8.0 92.0
8.1 92.4
8.2 92.8
8.3 93.2
 
hotrod coupe said:
any rough guidelines for limits on a 2 bolt 350
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Strictly Attitude already answered this correctly. Please repost the engine porn pics of your splayed caps for hotrod coupe, John.
Strictly Attitude said:
383 needs a 4 bolt block or the caps will walk. You have to remember the block you have was designed for a shorter throw and the larger inertia loads will give cap walk been down this road. Do you already have the block if so you could try the arp main studs an a girdle. This is where I had a tough decision to make on my build splayed caps won.
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I re-read Strictly Attitudes entire build thread. Here is that picture:
index.php
 
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be aware that, the fuel octane, being used, alone is not the only factor here!
iron heads hold heat and transfer heat to coolant at a lower rate!
running a 180f -190f t-stat and use of a 7-8 quart oil pan, an oil cooler will tend too lower the effective operating temp.
both the coolant and oil temps, and ignition advance curve, will effect the range where detonation will occur,richer fuel/air mixtures (12.5:1-13.5:1) tend to burn a bit cooler than lean mix ratios,(13.5:1-15.5:1)
aluminum heads, transfer heat much faster, and benefit from, some, simple mods , like keeping the quench in the .040-.042 range, polishing the piston deck surface and combustion chamber and rounding the edges on the combustion chamber and piston valve notches, will reduce the tendency to get into detonation
 
ok if this block checks out good I will go with a 350 scat 9000, I'm assuming internal balance is better, using the stock rods and replacing the one, aluminum heads. any opinion on brodex, they're under a grand compared to 1600+ for afr. 32 highboy headers extend out 14" and run down the outside to just in front of the rear fenders and i am not seeing any other support than the head mounting points,this concerns me. planning on using a kevko oil pan that is 7" deep 6 quart for ground clearance. air gap manifold.
 
Quench you can run a real tight quench if you have a forged rod and crank less stretching lower rpm and a piston that will not expand much. .040-.042 is a good distance. piston rock also needs to be taken into consideration.
 
"for quench stay at .040-.042 with hypereutectic pistons? .035 is too tight?"

Ive seen a few guys get away with clearances that tight, (.035)but most show contact marks on the heads
 
Brodix aluminum heads under $1000 assembled. They seem to be cast will need work. Look you are going to see your biggest gains from heads check your crank out before you replace it that is $250 that could go to heads. You would not believe the difference it is to put a quality head on a car is to you have done it and drove it. Night and day difference. You can make your own decision here but a cast head will need port work to flow properly will it be a better option then a factory head yes. The CNC porting in the AFR's is why they perform flow numbers are amazing and the velocity stays high for a 195 runner. Big picture break out a pad of paper here and get ready to write stuff down cause if you don't you will not understand the true costs you are about run into. You can contemplate this stuff now but if I was you if you don't have the tools to disassemble and inspect your parts I would be shopping for those tools first. Then when you know what you are working with to get a real parts list put together. I know there is times where you will sit in front a comp dreaming up the build which is fine start simple. Cost of gaskets, new oil pump, costs of bearings, cost of rings these can vary but are needed. Do you plan to open up oil drains and make sure oil holes line up with bearings. You will need burrs and at least a dremel, electric die grinder or pneumatic die grinder.

Reality-Not trying to discourage but Lets be Real
Let's say you pull the block tear it down.
1st thing you need to do is see what is reusable can't make a parts list if you don't know what needs to be replaced.
I am assume you have an Engine stand or have access to one and a hoist to mount the engine to the stand.
So you are now going to tear your engine down time to get organized and get a pad or engineers log book my favorite to keep notes and measurements in.
You will need at minimum
A Valve Train tray $20 or build your own your choice but keeps you organized.
You will need a bore gauge set you can chose how much to spend.
You will need Micrometers to measure your crank journals and your piston clearances along with setting your bore gauge.
At least a 6" caliper and a 12" is nice to have but optional.
You can build a crank stand out of wood suggested not a total necessary.
The Block needs to go be Magnafuxed and hot tanked after removing all freeze plugs and complete disassembly. Think it cost me $230 I do not remember might be on my thread

This is Bare minimal in my opinion
 
hotrod coupe said:
32 highboy headers extend out 14" and run down the outside to just in front of the rear fenders and i am not seeing any other support than the head mounting points,this concerns me.
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I assume your concern is the weight and leverage of the headers and exhaust hanging on the 6 header mounting bolts threaded into aluminum?
I personally do not have experience with this. Rick, (Indycars) might be able to provide some input here.
Edelbrock aluminum heads come with heli-coils already installed for the exhaust mounting bolts.
 
I've never heard anyone on the TBucket forum having trouble with the bolts that hold the headers to the head. With my 24" extensions to the collector, they do bounce about 1-1/2" at the tip. I don't like the looks of them bouncing so I have supported them at the collector, which eliminates all the bouncing. My engine is mounted very solid and has little movement in the frame, so there is very little twisting/stress coming from the engine movement.
 
finally got the motor out of the Yukon and cracked open. bores look good and rods are tight the noise came from #5 bore that lost the big end rod bearing, no marks on head or piston of hitting. will see what it looks like better next weekend.
 
as always, clear, posted pictures would be very helpful
it sounds like you caught the problem early that might have prevented serious
(and more extensive and expensive ) damage
 
got the engine broke down today, not so good. I believe the crankshaft is a loss, 4&6 rod bearings spun along with the 3 main bearing. main bearing was loose in the bore but measures the same with a dial caliper. just checked with the caliper for a rough idea of how bad it was. will post picks as soon as I figure out how.
 
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