Rat Manure!

[409ina50buick]

That 333 is an okay head.Afterall Jason [Yellow Wagen]'s little 417 or so cubic inch 409 made 470 plus hp on a hot,muggy day.I would say that this package would really like an Edelbrock Performer RPM single 4bbl intake to go with that 750 Holley.If you're using an adapter on the stock truck manifold,you'll be losing at least 30-35 hp.

We hogged out the center section of the intake and machined an aluminum block that was a matched fit to the Holley and attached it to the intake with a 1" open spacer in between to act as a plenum. Desperate measures were necessary in those days. I am amazed at the shear volume and depth of parts available today. No one was making intakes back then, and used ones were non-existent.

My biggest worry is push rods. The 348/409's were hell on push rods in the day. Any recommendations on push rods?

 

[1958 delivery]

Originally, Bill Rogers (Rogers Machine Shop, CC, Tx) and I had a goal of 6000rpm max because of using the original rods. We figured that short stroke and big over-bore would wind like a bat from hell. I was a street racer back in those days. I had a '68 Vette with a 383ci internally balanced engine that was the cat's meow. I was going to replace the 383ci with the now 424ci 409 engine. I got married instead. Street racing was out. Now she is gone with most of my money, all of my dignity, and my darned horse. She was a real looker, with a $15,000 set of rebuilt hooters, but mean as hell. Now, I can do what I want. Now I just want to spin the tires again, and sit and smell the smoke.

View attachment 62083

YOU WISH

 

[Don Jacks]

The biggest problem with the push rods were poor valve train geometery and idots over reving the engine.You can open up the push rod holes in the heads for a 3/8ths. pushrod.

 

[409ina50buick]

The biggest problem with the push rods were poor valve train geometery and idots over reving the engine.You can open up the push rod holes in the heads for a 3/8ths. pushrod.

Sounds reasonable. Is there any tangible advantage to using a tapered push rod?

 

[Don Jacks]

Not at the RPM that this engine will see.

 

[409ina50buick]

This is what has been done to this engine to date. All is from memory, and I am an old man.

Original goal: 400hp @ 6000rpm (light weight car - '68 Vette w/Muncie M22 & 11" clutch)

Block
1965 N80 HD truck block
Dipped and boiled
Line honed
Bored 0.120" os
Honed to 600 grit w/Sunnen CK10
Decked just enough to clean all marks from surface (less than 0.010" from memory)
New brass freeze plugs
Studded entire block
New cam bearings
Ross Hyperutectic pistons
CC'ed block and heads
Rotating assembly internally balanced to less than 1 gm
Target static CR was 9.5 to 1

Crank
Turned 0.010"us
Polished
Chamfered oil holes

Rods
Resized big ends
ARP rod bolts
Shot peened polished beams (don't remember shot size or type, but believe it was lead)
Converted to floating pins

Heads
333 truck heads original to block
Hardened seats for exhaust
Valves are SS and were ordered from some guy in Australia, 2.25 intakes & 1.75 exhausts
Brass guides all around (spirals?)
Ported by Rogers Precision Machine w/special attention to valve seat entries/exits, port matched to intake
Installed studs for rocker arms
Cut for valve stem seals, enlarged valve stem guide holes for 3/8" push rods
Enlarged drain back holes
Decked heads just enough to remove all marks
3 Angle valve job

Cam
Comp Cams 280 HE (roller rockers hit valve covers at max lift)
Rhodes lifters
Roller rockers and locks (can't remember ratio)
Cloyes True Roller timing chain

Stock balancer
11" flywheel
McLeod clutch and pressure plate
Explosion proof bell housing
Muncie M22 transmission
Stock Vette shifter
Mallory Pointless distributor
Super coil
Sanderson headers
750 Holley DP
Original intake adapted for Holley 750

Been in storage since 1991. Tearing it all apart to clean and reassemble. Dirt dobbers found every hole.

Jim

 

[Don Jacks]

The good old 280 Magnum cam.If you got roller rockers,they were likely 1.7's.This cam has a lift of .520 intake and exhaust,Advertised duration,280-280,duration at .050 230,lobe seperation angle,110,intake opening centerline of 106.With your package,you should make around 380 horses by 5,000,she'll drop off slightly by 5500,and really drop off by 6000.Your torque will peak about 3500,and with the slight "varible cam timing" effect from the Rhodes lifters,will be very broad.Just buying the new Edelbrock intake would put you at about 415 hp,and torque would increase by a little more as well.

 

[409ina50buick]

Damn, Don, you just talked me into buying an Edelbrock intake manifold - I presume you are referring to the Performer RPM? That's cheap horsepower.

 

[Don Jacks]

Yes That's the one.Be certain to get the small port version in order to match your 333 heads.I mocked this package up on my new simulator,and if you saw the graph of the curves,there'd be zero doubts in your mind as to which way to go.Are you going to use the shorty headers in the Buick,or are you going to have to make up a set for the application?

 

[409ina50buick]

Yes That's the one.Be certain to get the small port version in order to match your 333 heads.I mocked this package up on my new simulator,and if you saw the graph of the curves,there'd be zero doubts in your mind as to which way to go.Are you going to use the shorty headers in the Buick,or are you going to have to make up a set for the application?

Gonna use the Shorty ones. Can you post the curves with the Edelbrock and Shorties (I will have a 2" pipes with Flowmaster's) from the simulator?

 

[Phil Reed]

The biggest problem with the push rods were poor valve train geometery and idots over reving the engine.You can open up the push rod holes in the heads for a 3/8ths. pushrod.

NOT WITHOUT GUIDE PLATES!!!!

 

[409ina50buick]

NOT WITHOUT GUIDE PLATES!!!!

I had made my own guide plates since none existed in 1991 that I could find. I will be replacing them with a more "modern" set. Mine were case hardened with a deadly poison whose name I cannot remember right now. We had a few fans blowing for that job.

 

[409ina50buick]

I will be sending these pistons to Rebco for lightening. The kicker is I will have to rebalance, depending on the amount of weight removed. I don't remember the original balance percentage. I realize the ideal percentage is an art form known only to those who have practiced the art for ages. I have a book that contains all the receipts, etc for the engine. In that book is the original balance card. I can weigh the individual components and back calculate the original balance factor, but I would still not know if it was ideal. Much work has evidently been done on many 409's since 1991, and maybe there is a consensus as to the ideal factor (I think we used 54%). Anyone here a balancing guru?

I have static balanced a few Harley engines in my time, and I still have all the equipment required. I suspect I could rebalance the assembly myself, and just might do so, if for no reason than to check the original work done by RPM. I have no doubt Rebco will return the pistons at the same individual weights, so only the crank is affected if I want to retain the same balance factor (the bob weights will change). My thought is that mayhaps the altered balance factor will be a more ideal one that our original judgement.

Making the bob weights for an eight cylinder crank should be just a ton of fun.

Any thoughts?

 

[Iowa 409 Guy]

I believe you will end up with a lot better engine today with the new technology than you would have in 1991. That Buick will be cool.

 

[boxerdog]

I'd guess if you re-match the pistons carefully, you will be fine. As you said, the balance factor is not a precise science anyway. I remember Harleys being a good example of that. Everybody had a "secret" number that they used. They all worked, and they all shook like Harleys anyway.

 

[Don Jacks]

I'm not computer literate enough to copy and post the charts that it came out with,but the shape of the torque curve in the rpm where you'd be using it is eye opening.

 

[409ina50buick]

Don, If the simulator allows you to save the charts, save them with a ".jpeg" extension. Then load the chart.jpeg with the forum attachment function and you are home free. Either that or do like I do and get one of your grandkids to do it for you.

 

[Don Jacks]

If it allows me to "import" these files.it's keeping it a secret.As to kids and grand kids,I don't have any of those,,,,,,,,,,,,,,that I know of.

 

[409ina50buick]

Using your mouse, right click on the chart and see if it gives you the option to save the chart.

 

[Don Jacks]

No,it won't.