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BJR Racing

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Well we've been at it again, just trying to get a little engine to make power. I'll list the parts and pieces,

318 1973 block bored .030
KB167 pistons
Square decked to achieve .017 out of block piston height
Balanced
Lightened factory rods 82 grms. and polished the beams
Resized both ends, and made small ends full floating without the bushings
Drilled 3/16 oil hole in small end for oiling pin
302 heads fully ported on the intake side and flows 232 @ .500 lift
Gasket matched the intake side to 360 port window
Bowl cut with 75* cutter on exhaust side (flows 188 @ .500)
Good comp. valve job to heads
Cut .030 off deck of heads and .036 from intake side of heads
Heads cc'ed at 57 cc's
Intake runner cc'ed at 136 cc's
Exh. runner is stock other than work mentioned
Valves are 85-89 302 318 stock valves on the intake side (1.78)
Exhaust valves are 67-69 318 (1.50)
Both intake and Exh. valves were backcut w/30* cut
Rockers are 273 rockers and pushrods
Valve springs are 110 on the seat and 290 open set at 1.68 installed
Cam is a Mopar .528 cam and lifters
Main and rod and cam brgs. are King engine brgs.
Crank is std./std.
Rings are factory type for pistons used
Gaskets are Corteco .055 to achieve .038 piston to head clearence
Intake is a Torker 340 but is being changed to a M-1 as we speak
Ign. is Mopar chrome box with a modified distributor (stock unit)
Distributor mod is the lean burn plate from late 70's single pickup (p# M-811 from NAPA)
Total timing is 30* @ 2500 RPMs
Total compression works out to 11.78:1
Carb is a 750 Alcohol carb that flows 1030 Holley # 9645 with 102 jets w/o PV's
2" carb spacer open hole type
1 5/8 Dyno-Max hedders with 18" Tq. tubes

This engine makes 470 HP at the flywheel and 376 to the ground. Here are the weather factors:
68*
62% Humd.
30.40 Baro.
Corrected Altitude 2309 ft. Above
Vapor pressure .428
Air Density 93.4
Correction factor for HP from the engine 1.073
So with the HP correction the engine made 354 HP on the first day with the Torker 340 Intake manifold.

Actual ET and MPH
7.534 @ 96.24 1/8 mile

The car hits the scale @ 3150 with the driver, 1970 Duster streetable.
904 trans. with PTC 5200 flash stall converter
Rear is a 9" Ford unit for simplicity with 5.29 rear gear
Tires are 29.5 X 10.5 X 15

We are adding a roll bar 8 point to the car so the car will now scale at about 3330 lbs. This is for safety as the car is getting to the point that it will be required anyway.

I know some of you guy's have been waiting for this build so here it is.
 
Thanks! My next engine will probobly be a 318, and that is a great buildup.
I assume the crank is a forged unit. How much did you have to deck it? And what kind of rpm will it see? Great job.
 
66,
The crank is a stock cast iron unit and I had to cut about .025 off the deck, but every block is different so the amount will be different. What you'll have to do is put a rod and piston together and in the block and then measure what you have and then you'll know what you have to do to achieve the result.
I turn this engine 6000 RPM's but peak power is at 6500 RPM's and peak Tq. is at 4500 RPM's.
 
Bobby,
There's lots of machining done on this engine. What is the total cost on the build? I won't be buying it, the wife put the brakes on that idea. She says the engine I have is plenty powerful. LOL

By the way, I signed up at nitromater. Great place to read and listen.

Jack
 
Jack,
The engine costs about $3,700.00 without the carb and hedders and ign..

The carb, hedders, and ign. adds about $1,500.00 more
 
By the way, I signed up at nitromater. Great place to read and listen.

Jack[/QUOTE]

This is a really neat site lots of Pro Racers there.
 
Thats about as cheap as I could do it for someone but as you know the cost of parts always is going up. I actually only had the parts invested as I do my own machining, so it really cost me about $1,000.00 without the carb. The rest is machine work.
 
BJR,

I've got a couple of questions regarding your build (suprise, suprise!).

1. Whats the purpose of the lean burn pickup plate?

2. Why not run more compression since you're running alcohol?

3. Why only 30 degrees total timing, are the combustion chambers that effecient?

Thank you and rockin' build BTW.
 
The lean burn plate is a fixed plate. You use it if you want to run without a vacuum advance.


Chuck
 
Ramcharger,
1. The lean burn plate takes the place of the vacuum advance pod and the 2 plates that cause timing flucuations when useing a timeing light. Basically it makes the timing when set with a light as steady as a crank trigger. Most timing marks tend to jump around when useing a light so if the plate is bolted or screwed in this case to the distributor housing it has to stay very steady. Then set the air gap at .008-.010 and your done.

2. Well a small block only has 10 head bolts and when cylinder pressures go up over 200 psi it tends to lift the heads under high rpms, and were already around 170-180 psi. Its due to the overlap in the camshaft only being 60*. OK I know run a larger cam and then more compression well this kind of defeats the purpose as first you build pressure and then you bleed it off. With the cam that I used it allows me to keep the Tq better at low rpms and this way I get to use all the cam profile without having to turn the engine up to 7000-7500 rpms. So its kind of a durability thing, and with the car weighing so much and the engine being so small that it needed all the help that it could get, and thats the reason that I built it this way. Which it isnt doing too bad as it is.

3. The combustion chamber and the port work that I did makes the engine very efficient, high velocity and fast burn chambers. This is another reason that I didnt run more compression. Also too that the more alcohol that you get into the cylinder the higher the pressures will be and I'm already running a 102 jet and it has a hole size of .130 X 4 jets plus bleed holes just above the jets that puts another .125 of fuel to it.

When ever you put more fuel to any engine the sound changes and it becomes rougher, healthier or deeper toned, this engine sounds like a roller 360 engine.
 
Thanks 340mopar! The newest mopar I ever had was a '74 so I never ran into the lean burn system.

Thank you BJR for answering all of my questions. I know I can be pesky at times but that's how I learn. :hello2:

1. I would imagine that a timing chain tensioner in conjunction with the lean burn plate would also help in regards the timing skipping around.

2. Ah yes, the dreaded head bolt dilema. Thanks for reminding me. On this note though, what about bumping up compression then spreading the lobe center vs. adding duration? I would think that this would add a little streetability yet extend your usable rpm but flatten the torque peak some. I'm assuming you didn't want to revert to a custom cam to keep costs down?

3. What can I say here but excellent job! It must feel great to have a plan work out.
 
BJR;

Could you explain to the general public, in short, what and how a correction factor is and how it effects what appears to be a large dip in power.
I'm wondering about the 354 HP level....is that flywheel of rear wheel?
At a 116HP drop between the two listed, it seems scary to someone new to understand how things work.
I myself am not to up on things dyno's do and how correction factors work and effect everything.


This engine makes 470 HP at the flywheel and 376 to the ground. Here are the weather factors:
68*
62% Humd.
30.40 Baro.
Corrected Altitude 2309 ft. Above
Vapor pressure .428
Air Density 93.4
Correction factor for HP from the engine 1.073
So with the HP correction the engine made 354 HP on the first day with the Torker 340 Intake manifold.
Click to expand...

I figured inquireing minds (Like mine) would want to know.
 
ramcharger,
Theres not enough room for a tensioner, as for the lobe centers it's already at 112, the further back the less overlap the cam has and the more cylinder pressure it would build.
Thanks for the compliment!

Rumble,
470 HP is what the engine makes at the crank then you lose 20% through the drivetrain which drops it to 376 HP then take 376 and divide by 1.073 and you have 350.4 HP as this is what the air hurts the performance. Sorry I had 354 and I ment 350.4. This is a direct relation to elevation and air quality and water grains. The worse the air the more it kills power in the engine.
 
So, we are looking at a 350 HP to the ground engine.
The correction factor is 1.073. Do you know how they come up with this number and does it change due to location?
 
Rumble,
It changes from the temp, humidity, and baro readings and from elevation. The correction factor comes from the amount of water grains in the air by %. More water more o2 less water less o2.
 
rumblefish360 said:
So, we are looking at a 350 HP to the ground engine.
The correction factor is 1.073. Do you know how they come up with this number and does it change due to location?
Click to expand...

Density altitude here truly kills power. Iv'e seen it above 9,000 ft. at Bandimere. Altitude sucks (power).
 
Thats why they have to raise the compression when they go there, or spin the blower faster and add more Nitro.
 
BJR Racing said:
Rumble,
It changes from the temp, humidity, and baro readings and from elevation. The correction factor comes from the amount of water grains in the air by %. More water more o2 less water less o2.
Click to expand...

Great info on your build,i like it a lot,,lol..
Its been a while but doesn't more water in the air displace 02 and less moisture make a denser charge..High humitity = a high density altitude,,wayne
 
Yes your correct I had it backwards, thats what happens when you have too many things on your mind at one time.
Have all the right info but put it down wrong.

Thanks for the correction.
 
340mopar said:
The lean burn plate is a fixed plate. You use it if you want to run without a vacuum advance.


Chuck
Click to expand...

I have always left mine unhooked because for some reason when I run a bigger cam than stock the motor will skip while at a steady RPM while traveling down the road. Unhook it.. plug the carb port no more skip.

Why does that happen?

With a fixed plate does that do away with the mechanical advance?
 
mullinax95 said:
I have always left mine unhooked because for some reason when I run a bigger cam than stock the motor will skip while at a steady RPM while traveling down the road. Unhook it.. plug the carb port no more skip.

Why does that happen?

With a fixed plate does that do away with the mechanical advance?
Click to expand...

Your vaccum advance is coming in and out,depending on your total advance curve and where it comes in,then in relation to engine vaccum.You can do alot with tuning a vaccum advance-even on a radical street car,I always run them to full vaccum port on the manifold and usually only add about 10-13 degrees to help idle and drivability and even a little better gas mileage.Its in at idle and at very low load situations but out the minute I gave it some more throttle.The vaccum advance operates by the plate being advanced by vaccum,so a fixed plate just eliminates the movement and the vaccum advance,it also gives you a rock steady platform for timing.I have to say I dont even mess with vaccum advance on my cars anymore lol,too lazy and theres no improvement in e.t. and I dont mind my car being a little nastier at low speed anyway.
 
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