will this crank work?

[Don Jacks]

Okay,reality time.#All Thumper cams listed are for hyd.roller set-ups[figure 1000.00 for cam and kit.#2 using a simulator for comparison,the smallest Thumper,when used in a 10.5-1 .030 over 402,with pocket ported,large valve[2.19-1.88] shows a dramitic loss of low speed power and torque as compared to say,an extreme energy of 274 ,with about the same power at the top end[which you'll rarely use].The 274 will have a "dont fu@k with me"idle,although not as bad as the Thumper.I'd go with the 274 it it were me.Fod for thought.:

 

[Bugsy]

Don, I kinda think like our young man. If i have a big block with a tunnel ram i want it to sound like the pistons are changing holes at an idle. how about a cam with someware around 320 duration and .600 lift

 

[Don Jacks]

How many inches,how much comperssion?Youre not known for "wimpy"small motors.

 

[Don Jacks]

As to your cam question,with the specs you provided,a 12-1 496 will peak between 7000-7500 rpm,idle like you want it,need at least a 4000 rpm convertor and about a 4.88 gear.It would take about 20 gallons of fuel for you to drive it from your house to Summerduck and back. Charlotte would love you for this combo.:evil:

 

[Bugsy]

I allready ran that with a 350 shot. it worked real good ran a 5.50 at the duck. as for charlotte i cant get her to drive the cars i built her.

 

[7d9_z28]

"as for charlotte i cant get her to drive the cars i built her."

OH OH PICK ME ILL DRIVE EM!!!!! PICK ME PICK ME!!!!
unless they are fords.

ill give you my address feel free to ship one my way

so a comp extreme energy , with 274-320 duration?

 

[Don Jacks]

Yes,thats about right.As to Buggsy,theres only one ford on the whole place,and it's a round track[asa]piece,out of 8-10 vehicles.And no you cant have the 64 Impala with the 482 in w motor.

 

[7d9_z28]

: why cant i? c'mon!
oh well

so how big a valve can i go if i use my stock heads? i think my stock castings use like a 2.08 intake which seems ultra small compared to the 2.19/1.88 valves in the 049 heads...

 

[Don Jacks]

The 049 heads did not come from the factory with 2.19-1.88 valves,they were installed afterwards.The same mods can be
done on your heads.For what you want,they'll be fine.

 

[7d9_z28]

i had another guy offer me a set of 049 heads with 2.19/1.88 valves, said he kept them stock incase he wanted to resell(figuring someone want stock for a restoration) but he want too much for em...

ok cool, yeah my stock heads are sitting on a shelf out in the garage, i suppose i could start breakin them down

i havent checked them for cracks, im thinkin of dropping them off at a local machine shop and havin them check em out and all... they have been called one of the best machine shops in the midwest, i dealt with them at my last job ( and the resurfaced the camaros flywheel when i toasted the last clutch!) and they did a great job

 

[Don Jacks]

To the best of my knowledge,the o49 head was made about 78 or so.This I do know,NO Chevrolet big block oval port heads came with the big valves,they were used on low compression ,smog controlled truck engines.The last production cars that had a rat motor was 1976 in Impalas[Caprice]and Monte Carlo.That jerk was pulling a fast one on you in more ways than one.Either that or he dosent know what he's talking about.Since you have connections with a very good machine shop,You can follow theyre directions and come out fine.

 

[7d9_z28]

how big can/should i go with valves in my heads?:?

 

[region rat]

If you have a set of open chamber oval port put valves in them. they will work ok. make sure those pistons have some dome to them, a little compression helps. I think i have a set of 12 to 1s for a 402 i got in a trade. i'll check a littlelater in the week. i'll send you a pm as soon as i check. Bugsy

I remember a lot of guys really liking the oval port, open chamber heads. I'd check with some one that knows better, but they used an extra set of rings in the truck motors and pistons were pretty heavy .Not sure what that would do when you went to balance it.
Bob

 

[Don Jacks]

Good point,Bob.For the power level he wants,a well machined stock 402 crank will be fine.There,be no reasoin to turn it over 6200 as most of it's power will come from mid range torque.properly machied and assembled it can run for years.

 

[7d9_z28]

i find it quite amazing that it started out needing all these other original parts, and its boiling down to all the stock parts i have being worked over and still putting out this huge amount of power...:?

I LIKE IT!

 

[Don Jacks]

Since youre going to have the machine shop check over the heads,have them do a cc check on the combustion chambers so we can get a starting point for figureing compression.

 

[Bugsy]

tomorrow i'll get out to the garage and i'll check those pistons. Don i'll let you know if they are open or closed chambered.

 

[7d9_z28]

this build has got me excited! you guys, are the best!

started working overtime at work again, less time for motor but more money for it!!! 550 horses here i come!!!

 

[7d9_z28]

did stock bbc heads come with guide plates? what about double springs?

 

[Bugsy]

big blocks came with guide plates but you need to find out what diameter push rods and get the correct plates. Don came by this morning to help me find those 12 to 1 pistons and i couldn't find them but i'm still looken. i'll be out there again tomorrow