Home | Register | Login | Contact Us

 
Auto Math
Classifieds
Forum
Gallery
Games
Garage
Tech Articles
Utilites
 
FAQFAQ    SearchSearch    RegisterRegister    Log inLog in    Log in to check your private messagesLog in to check your private messages    Forum Subscriptions1/4 Mile Table 

Chevy 416 Heads
Goto page 1, 2  Next
 
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1
View previous topic :: View next topic  
Author Message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Thu Feb 02, 2012 9:07 pm    Post subject: Chevy 416 Heads Reply with quote

I am trying to make the most out of my 416 heads that are being put onto a 305. I currently have 1.94" intake valves installed but I am looking to have the exhaust cut to accept 1.6" valves instead of the stock 1.5" valves. Will the 1.6" exhaust valve fit into the 416 head and will the valves clear the small 305 bore?

Thanks Alot!!
Back to top
View user's profile Send private message
af2
Member


Joined: 01 Sep 2003
Posts: 5398
Location: grassvalley, ca
66491.04 points


1933 Willys Coupe

PostPosted: Thu Feb 02, 2012 10:19 pm    Post subject: Reply with quote

Make the intake as big as you can. The difference from a 1.5" to 1.6" exhaust is nothing to worry about.


Did you look at Stan's site?
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Thu Feb 02, 2012 10:56 pm    Post subject: Reply with quote

Yeah I did. Thanks for the link to the page but there was a statement added to this years rules stating that the head must be stock to the motor being used. So are the 416 heads the best? I also have a set of 081 heads that would need freshened up. Would these be any better? Also, I am tring to squeeze every little bit out of this 305 and from my knowledge, a engine that is able to breath (in and out) will run better than stock. Will the 1.6" valves help enough to notice a difference on the track?

Thanks!
Back to top
View user's profile Send private message
squeeezer
Member


Joined: 02 Mar 2007
Posts: 2414
Location: new richmond WI
191175.26 points


1991 Chevrolet Camaro

PostPosted: Fri Feb 03, 2012 6:26 pm    Post subject: Reply with quote

imo i dont think making the valves bigger will net anything in a 3.736 bore
what happened to your 311 idea?????

_________________
Back to top
View user's profile Send private message
Big Dave
Moderator


Joined: 04 Dec 2005
Posts: 2547
Location: Tampa Florida
116113.74 points



PostPosted: Fri Feb 03, 2012 7:45 pm    Post subject: Reply with quote

The bigger valves actually hurt air flow due to shrouding of the cylinder wall. The 305 bore is too small to support a bigger valve unless you cut notches in the block down to just above the top ring (don't get too close as the rings sweep up and down and you do not want what little compression you built up to escape).

Big Dave
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Fri Feb 03, 2012 8:33 pm    Post subject: Reply with quote

Thanks for the help guys and the 311 is an ongoing project but it will not be done by the time the season begins so we need to start the season with the 305. Any suggestions on making more power with the 305? How thin of a head gasket can I pull of with the 416 heads that are milled .025"? Also I was looking into an aluminium flywheel that is 11 lbs compared to a 17lb steel one. Would this swap, saving 6lbs of rotating weight, be worth the money/

Thanks
Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3156
Location: South Carolina
315996.97 points


1972 Chevrolet Nova

PostPosted: Fri Feb 03, 2012 9:40 pm    Post subject: Reply with quote

Heads being milled has no bearing on how thin a head gasket you can run. You need around 0.040" clearance between the piston and head at tdc. If you mill the head, it's still flat - nothing changes there. Measure how far the piston is down in the cylinder at tdc. Usually it's around 0.025" - 0.030" down. If this is the case you can run the 0.015" steel shim gasket to help compression. All this is assuming you are running a flat top piston. If you have a dome you still probably won't have any problems but if you really get into angle milling the heads with a large dome you could. I'm guessing the aluminum flywheel won't be worth the money in your application. Since you are in a limited class I'm guessing the rpm's aren't climbing fast enough that it would help. I could be wrong on that though. You might have put some of this in your other post - I'll look after I post this, but what are your carburetor, intake, and exhaust rules? Seems like it was hydraulic flat tappet camshaft, how about rocker arm rules? Clay

Edit : Saw the carburetor rules. How about intake? I would probably get a custom camshaft. How about specific porting rules?

_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Sat Feb 04, 2012 1:22 am    Post subject: Reply with quote

Ok thanks for the help!! To fill in the gaps.. The 305s in this class are far from stock 305s. They will run circles around a stock 350 on the track from previous experience. The intakes must be a 2bbl intake with a stock casting number stamped on it. That is it. I would like to run the .015" head gasket to boost the compression up a little bit also.We are required to run flat top pistons. The aluminium flywheel i thought might help because from corner to corner the car needs to accelerate as fast as possible and I know eliminating rotating weight has make some kind of difference. I normally turn 6200 rpms at the end of a straightaway. The exhaust rules call for a stock manifold but we are running the "Ram-Horn" design and the car has passed tech several times already with nothing said.

Thanks!!!
Back to top
View user's profile Send private message
Big Dave
Moderator


Joined: 04 Dec 2005
Posts: 2547
Location: Tampa Florida
116113.74 points



PostPosted: Sat Feb 04, 2012 11:28 am    Post subject: Reply with quote

These guys take what Smokey started to extremes.

http://www.castheads.com/

They use a slurry of sand and aluminum oxide in water to open everything up improving the flow rate. They claim their cast iron exhausts flow as well as a long tube 1-5/8 th inch primary headers, and that you can get similar gains from their intake treatment.

Big Dave
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Sat Feb 04, 2012 12:54 pm    Post subject: Reply with quote

Those guys seem like they have the cast iron running just as good, if not better, than some of the aftermarket heads/intakes. As far as buying their stuff, they are pretty expensive and that is most likely out of my price range. Do you know how I could possible do something like they are doing with the intake/heads that I already have?

Thanks!!

Also, do you think the aluminium flywheel will help?
Back to top
View user's profile Send private message
Big Dave
Moderator


Joined: 04 Dec 2005
Posts: 2547
Location: Tampa Florida
116113.74 points



PostPosted: Sun Feb 05, 2012 11:46 am    Post subject: Reply with quote

Smokey Yunik built a simple tank with a bottom drain that recirculated a mixture of sand (he lived and worked on Daytona beach so all he needed was a shovel) and water. He machined a fixture that connected to the end of a three quarter inch rubber hose that came off a cheap pool pump at the bottom of the tank that sucked in the sand and water and pumped it up to the head where it bolted up to the head side of intake port (it would also bolt to the intake manifold).

He went through a few pumps as the sand errodes everything but as he could attest he had never ported anyting which would have been a violation of the rules back then that out lawed grinding on the heads and he believed everyone should follow the rules. (of course he interpreted the rule book as saying if ithe book didn't out law a specific idea he had then it was obviously legal to do it).

Big Dave
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Sun Feb 05, 2012 12:06 pm    Post subject: Reply with quote

Ok so the trick here is pumping a mixture of sand and water into the heads and intake manifold? Would rigging this sand/water machine up to the heads help eliminate uneven spots and improve flow? Also I have access to a sandblaster... Would sandblasting the intake/exhaust ports help improve flow?

Thanks guys!!
Back to top
View user's profile Send private message
Big Dave
Moderator


Joined: 04 Dec 2005
Posts: 2547
Location: Tampa Florida
116113.74 points



PostPosted: Sun Feb 05, 2012 2:01 pm    Post subject: Reply with quote

The water will find the course of least resistance and wear away anything that gets in it's way. It is cheaper than sand blasting and can be left for hours unattended without wearing out your compressor or burning through tips. You are attempting to improve the flow in the throat area and the slurry will open it up and provide a smooth contour (transition as the air and gas have to bend ninety degrees). You just have to keep checking periodically the progress to be sure you don't burn through the port wall, and expect to replace the valve seats with new ones.

Big Dave
Back to top
View user's profile Send private message
clay
Moderator


Joined: 24 Nov 2002
Posts: 3156
Location: South Carolina
315996.97 points


1972 Chevrolet Nova

PostPosted: Sun Feb 05, 2012 8:42 pm    Post subject: Reply with quote

O.k. - from what you are saying the aluminum flywheel might make a difference. On the intake - have you done any modifications to it? Are you running a spacer of anykind? What I'm thinking is either cutting the intake divider away under the carburetor to let each cylinder effectively see both barrels of the carburetor. An open spacer will effectively do the same thing. Just another thought. Clay
_________________
I have done so much with so little for so long, I can now do anything with nothing.
Back to top
View user's profile Send private message
jtb0322
Member


Joined: 29 Jan 2012
Posts: 23

994.54 points



PostPosted: Mon Feb 06, 2012 1:08 am    Post subject: Reply with quote

I am pretty well sold on the aluminium flywheel and as far as the intake goes I have one that is just polished and one that has the divider already cut away from it. Which one is better to run? Also, I plan on trying to bead blast or use the slurry technique to smooth out the intake. Can anyone give me a little bit of instruction on how to make a cheap setup? Like what gph pump would suffice to do the job? One more question... If I use the slurry on the heads, what would I have to do to the valve seats afterwards?

Thanks for all the help!!


Edit: We are not permitted to run any type of carb spacer.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    SMOKEmUP.com Forum Index -> Chevy - Small Block Gen 1 All times are GMT - 5 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
Home | Contact Us | Automath | Cam Files | Dyno Search | Forum | Garage | Picture Gallery | Reaction Timer

Copyright 1997-2014 SMOKEmUP.com All rights reserved.
Advertising Info     Disclaimer     Privacy Policy