Thread: 500 hp/550 lb-ft from a 390?

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Originally Posted by pat mccarthy

general kinetics were good cams in there day. that guy that started GK work for ford and started his own cam grinding company . i can not think of his name right now it was in detroit

I think maybe that was Harold Brookshire.

Originally Posted by techinspector1

I think maybe that was Harold Brookshire.

no don tewless

I know they ground me a cam that ran High 9's with the linelock locked up!!!
That was in a mustang with a 351C in it.
They had ground me the same cam Bob Glidden was using back in 73
when he won the world championship.
Glidden was using a destroked 351C down to about 330 and it was not long before we found out why he destroked it. We kept cracking blocks in the lifter galley with the higher RPM's. I imagine the shorter stroke stop the craking there.
We ended up going with a smaller cam and lowering the RPM's below 7,500 to stop the craking. I guess the destroking took alot of stress off the blocks for Glidden.
Kurt

Originally Posted by vara4

I know they ground me a cam that ran High 9's with the linelock locked up!!!
That was in a mustang with a 351C in it.
They had ground me the same cam Bob Glidden was using back in 73
when he won the world championship.
Glidden was using a destroked 351C down to about 330 and it was not long before we found out why he destroked it. We kept cracking blocks in the lifter galley with the higher RPM's. I imagine the shorter stroke stop the craking there.
We ended up going with a smaller cam and lowering the RPM's below 7,500 to stop the craking. I guess the destroking took alot of stress off the blocks for Glidden.
Kurt

my older engine builder buddy used GK cams. when you talk about cams to him harold B name would pop up . i do not know if harold in is very early days if he work at GK ? i think he did work for comp in the early 80s ?

Just wondering one thing. Speed Pro piston is designed for connecting rods that are 6.480.
Are they not 6.490? Maybe it doesnt matter?

Johan

Originally Posted by Johan78

Just wondering one thing. Speed Pro piston is designed for connecting rods that are 6.480.
Are they not 6.490? Maybe it doesnt matter?

Johan

When you are sitting down to engineer all the parts that will make your motor work like you want it to, you determine the static compression ratio and squish you want to use in the motor, then purchase parts to reach those specifications.

Let's say for instance, that you wanted to achieve a squish of 0.040". OK, we know the block deck height is ~10.170", so we have to put together a stack of parts and adjust the block deck height to achieve a zero deck to do this. The thickness of the gasket then becomes the squish figure. So, with a stack of parts like this.....stroke radius 1.890", rod length nominally 6.490" (can vary from 6.486" to 6.490" in production rods) and piston compression height of 1.776", we would add all the stack pieces together and find that we have a stack of 10.156" So, in order to achieve a zero deck, we would have to shave the block decks 0.014". If the rods were actually 6.480", then the stack would be 10.146" and you'd have to cut the block decks 0.024" to achieve a zero deck.

I know this forum is older than dirt...but I am another newb building a 390...just wondering why that C8AX-6250-C cam was never mentioned

Originally Posted by Flatheadwillie

I know this forum is older than dirt...but I am another newb building a 390...just wondering why that C8AX-6250-C cam was never mentioned

After re-factoring the flow of the Edelbrock heads, based on Barry's experience with hard dyno pulls with these motors, I ran a Sim on this cam. Best results were achieved with the cam retarded 4 degrees on these 0.050" marks....
IO (-5)
IC (45)
EO (52
EC (-2)
RPM....HP....TQ
2000...166...436
2500...208...436
3000...263...460
3500...330...495
4000...397...521
4500...447...521
5000...492...517
5500...505...482
6000...485...425
Peak volumetric efficiency 101.8% @5000
Peak BMEP 198.8 lbs @4500

I'm new to this forum but not to Fords or the mighty FE engine. I have a 1969 Ford LTD 427 Cobra clone. It still has its 390 though its dressed up as a 427. I don't have all the specific details as I had the work done at local speed shop. It has a high lift cam,aluminum intake,700 cfm carb.,head work,electronic billet distributor,long tube headers and dynoed at 451hp. The secret to 390 is torque as its no high revving engine,get a nice gear 3:89 or 4:11,posi unit,stall 2000-2500,shift kit,sticky tires and spank some Chevy butt. I beat a ton of cars with more hp than me. I get them out the hole and they never catch me!!! I run 2200 stall and 275/60/15 Cooper Cobra's. Good luck but you won't need it!!!

While it's great that you replied.. the last post was almost a year ago! And you're right, the FE's were torque motors.

Dang = That's Purty! Welcome to the club..

Funny how the world works....I've spent the past two weeks revisiting this build. The bottom end is going together at the shop and I literally, just last night, drilled the lowering holes and installed the upper control arms.

I got distracted by building a couple of businesses and a career. Believe it or not this one isn't as dead as one might think.

I'll post a few pics at some point today, at least of the suspension. The engine assembly is being documented fairly thoroughly by the shop I engaged to do that and we'll have actual dyno numbers to look at.

Again, how strange the world can be...

Cheers

Jeff

Hi Ya Jeff. Yep, sometimes we are the last to know what's coming next right??
Can't wait to see the pics.. been so long I've forgotten what the motor was going into.
A Mustang perhaps?

Loading pics from a phone is obviously a pain....I'll need to transfer to a computer and figure it out from there....gimme a minute...

And yes, the car is a Mustang. 1967 Coupe.

https://www.dropbox.com/s/rwb74mabr4...25542.jpg?dl=0


Try the link above for a pic of the suspension....I'm apparently not bright enough to upload a picture here. Nevermind the fact that I build communications networks nationally...