diehrd

350

9.8-1
Fast Burn 62cc heads
575/595 lift 238/242 duration 112 center line
1 7/8 headers
Full 3" dual exhaust
1000 CFM Fast F/I
Single plane intake manifold
700R4
2600 stall
3.92 gears

StraubTech

If that is a roller cam it is way to much duration and not enough split. Lobe sep can be much tighter.

hugie82

I would double check that compression also. 62cc is a pretty small chamber if you're running flat top pistons. Not saying that's a bad thing and that cam would work well with higher compression.

diehrd

How would it perform as listed in your opinion ?

StraubTech

lazy until about 4000 rpm

diehrd

It is a roller cam . . I bought the lifters from you !!

StraubTech

If it was a flat tappet it would be 256/260 @ .50". Large for a 350 CID engine.

Thank you for the patronage.

diehrd

The set up copy's and improves on a Crate zz465 ... My improvements are a way better true dual 3 exhaust , 1 7/8 headers , single plane intake , fuel injection and MSD Ignition..

I was set up as a ZZ430 before I made the above changes ( 430 hp 430 tq )

In LT4 motors with that cam many put down 390 to 420 rwhp. I have not put the car on a dyno but from the zz430 I was running this set up dogs that one easily ..

It also is better in daily driving , better at low speed high loads and even idles as well as the LT4 Hot cam I had for the ZZ430.

I am guessing but this cam and these fast burns seam so perfectly matched I can not imagine how a different profile cam would make it run so well in all driving conditions.

gkull

If I am reading this right........... The above is what you have now?

diehrd

Yes

StraubTech

2 years ago I got a project that my customers customer was told their wasn''t anything left in the combo, for a 23 degree 406 SB it was maxed out after 7 years of perfecting it.

A cam change to a smaller cam and the un-improvable was .2th quicker.

The combo may make good power, but there is still room for improvement if and when you want too.

gkull

i was trying to find some flow numbers on the 210cc intake fast burns.

http://www.superchevy.com/how-to/031...ng-horsepower/


I think that the small valve size aids in your ability to run a cam @20 degrees more than the GM ZZ hot cam.

diehrd

The cam was used on LT4 motors ,, 1.94 intake and 1.5 exhaust.It is older technology , was used on F/I motors and people almost unanimously loved it. It is also well known for laying waste to bottom ends because it will build power to 7200 rpm ..

I did this build because I have always thought a 383 to be a waste unless your going for 550hp and 525 tq which is very rare . The 383 set ups I have seen here on the forum and in town , most are 420 or so hp and torque. For 550 plus I say jump to a 406/ 421/ 427/434 .. Spend the money get the cubic inches ,, but 500 hp I can not see why any 350 wont give you all of that and have street manners.

I posted this topic because I sorta new some would say it cant run well wont make power ect ect ect ... Some said that about the fast burn head.. ( supports 500 + hp out of the box )

The truth is I have to be at or so so so close to 485hp that saying I have 485hp can not be seen as a lie .. And all of it was done with GM parts

StraubTech

350 CID, 4.00" x 3.48 stroke needs 1.90" of valve area to make power to 7000 rpm
372 C"ID 4.125 x 3.48 stroke needs 1.90" of valve area to make power to 6600 rpm
377 CID 4.00 x 3.75 stroke needs 1.900" of valve area to make power to 6500 rpm
400 CID 4.125 x 3.75 stroke needs 1.900" of valve area to make power to 6100 rpm
427 CID 4.125 x 4" stroke needs 1.900" of valve area to make power to 5700 rpm

So if all things equal, each engine would max the cylinder head out at that rpm. Can you make power higher, YES. The cam would then have to be manipulated with more duration as now the job of making power is now more cam oriented since the heads are maxed. The compromise is the powerband will be peaky and very narrow.

cardo0

When u get over 280 degrees full duration of cam u need to calculate the dynamic c.r. - i think it because the intake vlv closing has a much larger effect at that duration. Anyways that large of duration cam can handle/need more compression. Try a compression test and see what your cranking pressure is. Should be 200 - 210 psi.

Just my best ball park guesstimate is your stall is a little low also. Something over 3000rpm would better match your cam.

Nice setup though. I think u are close to a mean azz C3.

bluedawg

When You say lt4 are you refering the mid to late 90's reverse flow engine? If so the heads they use are different then the heads that fit a gen one or two small block.

diehrd

LT4 had reverse cooling that head was the stepping stone to the fast burn combustion chamber and tall intake runner.

Not sure on cranking pressure and took on faith GM had some idea these parts would play together well.

Stall speed .. Here I am not sure if higher would be better.The cam profile is 2k to 7200 .. I am at 2600 stall. When I launch with a power break and nail it this car makes the tires useless as if I am in the snow.

When i do go for full power take off's I do it from idle and just punch it and tire spin is there but only for a car length and it shoots forward pushing me back in the seat pulling like mad. More stall may cause more tire spin.

Between my dislike of 383 CI and my belief a c-3 is at its limit with 500hp without serious changes to the suspension and chassis . I think I mixed and matched gearing trans and motor pretty well here.

And I have to include this forum and several others for all the reading material and information I have gathered.

Now to MR Straub .. Once I tire of this engine combo I will set up a 427 , taller gears and a 4L80e 6 speed automatic in this c-3 and will then need a cam that GM never had time to dream up I am sure you can help me next season or at the latest the one after !

gkull

I have a 383. I build it when I first had lots of free money and I was tired of problems with 355 ci 7200 rpm motors. It was only 383 because it was going to take time to get a big buck 3.875 inter.al balanced forging for a 396 sbc.

The first thing i noticed about the 383 was the additional 30-40 foot pounds of TQ over a 350

diehrd

I am not sure most 383 have that much more torque then the motor I have now. GM rates it at 440 ft pounds at 4600... I would guess I may have a tad more then that.

And for sure the 383 makes it's torque sooner. Most I have run with display that with tire roasting I can clearly see in my mirror Bahahahahahahahaha .......

mvette76

how about 494tq 520hp out of a 383 using one of straubs cams