OK....here are the numbers
installed height and pressure 130/140 @ 2.00"
Open pressure 435# 1.375"
Coil bind @ 1.120"
Retainer seal clearance @ open .840
Specs with a .625 valve lift

Comp recommended #08-422-8

 

OK....here are the numbers
installed height and pressure 135/140 @ 2.00"
Open pressure 435# 1.375"
Coil bind @ 1.120"
Retainer seal clearance @ open .840
Specs with a .625 valve lift

Comp recommended #08-422-8

 

Ok with the springs installed 2.00 and coil bind at 1.120". You subtract the 1.120 from 2" and you have .880" of possible cam lift. If the cam is around .625" that leave almost .200" of travel for the spring. This is not good. It will allow the spring to rebound and send a wave back through the valvetrain. Most SBC heads are set up around 1.800"-1.900" installed height.

 

OK, I understand what you are saying regarding the spring rebound. My simplistic thinking tells me that if I get a cam with .880 lift I will be OK.....budget wise I'm not able to change the intake, rockers and springs right now so if at all possible I need to work a reasonable can into the current configuration

 

.880" cam will not work in your combination. It would be WAY TO MUCH for the engine along many other reasons.

 

If I change the rockers to 1.6 will that allow me to reduce can lift to a reasonable range? Or do I need to change springs also?
I am going to use the we I and g intake and eliminate the super Vic also.....I just need to space it so the air cleaner is through the hole in the hood

 

To do this right the spring height needs to change or you can risk damage to the valve train. Spring surge can lead to a dropped valve and a dropped valve can be a catastrophic failure.

 

OK' I'm gonna have new springs installed and change the rockers to 1.6
This engine is a project I purchase and the price keeps going up......ahhhh, the cost of ignorance

 

OP has a 406, 210 heads, hydraulic roller cam with a max of 6500 RPM. Your 383 has 210 heads, solid roller, 7000+ rpm engine. Very similar, almost exact, intake demand. Your present engine is a 434, Bigger heads, Solid roller 7000+ engine. Bigger intake demand.

 

Is this the kind of power your looking for? This is an AFR195 headed 383

 

I have a dyno sheet in Adobe Acrobat of a 406 with AFR 190's If you want that dyno sheet I can email it too you. Hyd roller.

 

Good talking to you Fred.

 

As soon as the heads are done to spec we can go ahead with the cam. When the build is done I may take it to another builder to have it broken in and tuned on the dyno.

 

What cam are you going with ?

 

.580 / .558
Getting the proper valve-train components installed and am dropping the super Vic down to a Vic Jr with some porting.

 

First cam offered me ..

580/564 w/ 1.6 rockers
237/241 .050
108 Sep sir.

I was told that cam would make 580 to 620 hp ? ? ? ? ? Yet you will be 500/500 ? I wonder how that works ...

I had a GMPP cam in a 350 .. Of course GM performance would be clueless on cam design, Obviously using a cam 234/242 .576/.595 112 LSA in a Crate 350 for the street makes them the fools. (ZZ465).. Apparently a GM847 is a 427 sbc cam not a 350 sbc cam. Can someone ring GM and let em know they made a huge mistake...
(PS) I ran that crate zz465 ..

Here is how to big a cam drives LMFAO (ZZ465)
http://vid1294.photobucket.com/album...ps12ff2120.mp4

Here is how a silly to big GM cam pulls LMFAO (ZZ465)
http://vid1294.photobucket.com/album...psf893deb9.mp4


Additionally , I also have a cam a hundred thousands less then my max spring lift .. If 50 to 70 is max to prevent damage I guess I am living on the edge ..

Max Lift of my heads , .710" , with 1.6 rockers I lift .611" / .592"

It is all the double talk that infuriates me ... It seams to me the best cam to buy comes from a dart board , a blindfold and an open bar surrounded by hookers and nuns...If that is not available you can pick a cam grinder there has to be one somewhere . . .

 

Many of the cams have been spec'd in by one source, that's what really pizzes me off. Specing in cams via PM ? Double secret motor-home cams as far as I am concerned, when they should be listening to forum members who have had success with with numerous incarnations of the big inch small block. They should be asking for more opinions from members that aren't making money on these puny cams.

Seems like someone asks for cam advice and takes only one persons advice via PM and the phone with his alter ego backing him up here and bingo the cam pops up, and neither of them have big inch small blocks, and don't realize a 350ci cam won't work in a 427ci small block which is the same as a 427ci big block and should be using heads and cam similar to a big block high performance build. It's getting ridiculous.

I don't even bother telling anyone what cam and heads to use because they never use them and listen to BS advice from someone that just doesn't know what he is talking about, pretty sad

 

What is the relevance of a 427 ci in this conversation?

 

The OP is running 1.7 Rockers. Rocker ration will change the duration the valve sees but not the duration the cam lobe sees.

Trying to judge a cam by lift is impossible. The OP's duration is much shorter and is not even close. Stroke swallows cam and in doing so doesn't affect the lift as much as it does duration. Lifts might be similar but the duration is not the same.

The OP's horse power is base on the lobe area. His lobes are nearly 20 degrees shorter and does not want to make power at a higher rpm. He is after usable power in a lower rpm. I don't feel 20 degrees of duration makes it the same camshaft.

The GM heads in the crates don't flow anywhere near what an AFR head does. The 195 AFR at .300" lift flows 198 the GM head flows 187. The GM head is 202cc, the AFR 195. Not only does AFR out flow the head it has better port velocity as it is smaller. Packing the cylinders quicker means it takes less time. Cam duration is time...how long we hold open the valve. If we do something faster it takes less time.

About your heads and cam lift. I did not build the engine. When we build an engine here we set the valve train up to the cam profile. If I had supplied the head than that is what we would have done. The OP's engine builder has been in contact with him and he agrees on what to do with the install height and is correcting his problem right now.

 

Your assumptions as to what is happening is just that. Assumptions. I get PM's, emails, and referrals everyday. No secrets. The cams belong to the customers. They can post what they want.

Your assumptions to my business are incorrect also. My main business is making and supplying part to the industry. The heads you currently have on your car have my parts. We supply 100K's of parts to other manufacturers every year. We supply engine builders components also. Working with shops on a 1 to 1 we supply valve train and cams to these guys. The feedback I receive is from all over the world whether it is a street driven 623 in Denmark or a 6.0L air boat engine in the swamps of LA. Some of these guys I have done business with for over 20 years. You don't build relationship like that supply inferior parts and sub par service. My owner ship of particular engine I feel doesn't affect the tech that I supply customers since we do our own R&D here along with the info I get from well respected companies in this industry.

I don't doubt that you have some technical info you can add but you need to look in the mirror and work on your delivery and leave out the snide remarks. Most on this board are successful career guys with many owning their own business. This success was not built on childish remarks meant to tear someone down in the attempt to make yourself look smarter. Doing this gives educated people a bad taste as it is very unprofessional. No matter how good your tech might be on a subject it is clouded because they have form a professional opinion of you.

427 CID is 427 CID. Whether it is referred to as "Small, Large, Chevy, Ford". There exist formula's to figure out a given induction size and a given exhaust size to make power at a given rpm. I choose to use math when developing a customers combination.

These forums give us a wealth of info to choose from. One must read and choose who they feel is giving good technical info and go with that choice.