Double Hump heads
#51
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by SSC
Agreed, I went that route on a few builds and never once ran into a flow issue. I was pushing some high numbers with 305 heads but the price of fuel was killing me.
1.94 valves are perfect for the street and strip 2.02's arent nessasary unless your running oval track and stay over 6k. Are you?
Agreed, I went that route on a few builds and never once ran into a flow issue. I was pushing some high numbers with 305 heads but the price of fuel was killing me.
1.94 valves are perfect for the street and strip 2.02's arent nessasary unless your running oval track and stay over 6k. Are you?
#53
Supreme Member
iTrader: (1)
Join Date: Oct 2001
Location: decatur IL
Posts: 1,056
Likes: 0
Received 0 Likes
on
0 Posts
Car: 86 iroc, 87 iroc, 89 iroc, 89 formula, 84 supra, 85 trans am
Engine: t\a motor 355 lt1 intake, t56,the works, 89 roc 427 sbc tt project
Transmission: to many to list
Axle/Gears: 9bolt 4:10 in the T/A
like my avitar
#54
Originally posted by @ZZKKER
like my avitar
like my avitar
I'm serious. The first time I saw that thing, I had just woke up. I strolled in here to check my email, and a friend had sent me one saying "To funny".
I about whizzed all over the computer!!! Now I can't stand to look at that pic. I'm too old to be scared like a little kid, but I am!!!!
Please take it down.
#55
Supreme Member
They're 492's?? And how much do they want for them? Grab em asap. Are they angle or straight plug? 492's are from the Vette and Camaro LT-1's and I would snap them up asap.
#56
Supreme Member
Mark :
The 492's are probabily the best of the "camel back" class heads.
As long as they are not cracked, I say go for it.
If they need new valves, go for the 2.02's and 1.60"'s
There is no difference in the price.
Either port them your self or get some one to do it.
Even a simple pocket port job will do, but the more effort you put into them the better they will work.
Yes you can get good flow out of ported 305 heads
but again it depends on the amount of effort your willing to invest.
By a Book by david Vizard called " How to build Chevy Small Blocks on a Budget" It explains what to do to these heads
and the results In a straight forward manor. It also covers the Vortecs and Corvette l98's
the kind of stuff in this book is what makes or breaks a good hp motor. Some you can do your self, some it's better to pay someone else to do.
Again as long as they are not cracked, go for it.
You can have them checked for cracks by "Magnafluxing" them.
Ask your machinist.......
The 492's are probabily the best of the "camel back" class heads.
As long as they are not cracked, I say go for it.
If they need new valves, go for the 2.02's and 1.60"'s
There is no difference in the price.
Either port them your self or get some one to do it.
Even a simple pocket port job will do, but the more effort you put into them the better they will work.
Yes you can get good flow out of ported 305 heads
but again it depends on the amount of effort your willing to invest.
By a Book by david Vizard called " How to build Chevy Small Blocks on a Budget" It explains what to do to these heads
and the results In a straight forward manor. It also covers the Vortecs and Corvette l98's
the kind of stuff in this book is what makes or breaks a good hp motor. Some you can do your self, some it's better to pay someone else to do.
Again as long as they are not cracked, go for it.
You can have them checked for cracks by "Magnafluxing" them.
Ask your machinist.......
#57
Supreme Member
Join Date: Jan 2002
Location: Addison. Il
Posts: 1,519
Likes: 0
Received 0 Likes
on
0 Posts
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
#58
Supreme Member
Join Date: Jul 1999
Location: Plano, TX
Posts: 1,817
Likes: 0
Received 1 Like
on
1 Post
Car: 1992 RS
Engine: 406 Stealth Ram
Transmission: 700R4
Originally posted by fattie92
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
#59
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by F-BIRD'88
Mark :
The 492's are probabily the best of the "camel back" class heads.
As long as they are not cracked, I say go for it.
If they need new valves, go for the 2.02's and 1.60"'s
There is no difference in the price.
Mark :
The 492's are probabily the best of the "camel back" class heads.
As long as they are not cracked, I say go for it.
If they need new valves, go for the 2.02's and 1.60"'s
There is no difference in the price.
So, considering their in working order, how much should I offer for the heads? With hardware and without.
#60
Supreme Member
Originally posted by Mark A Shields
Well, they already have all the hardware with em including 2.02/1.6s. But, now his dad is saying he may not part with them or that he might keep the hardware, I already have matching valve springs.
So, considering their in working order, how much should I offer for the heads? With hardware and without.
Well, they already have all the hardware with em including 2.02/1.6s. But, now his dad is saying he may not part with them or that he might keep the hardware, I already have matching valve springs.
So, considering their in working order, how much should I offer for the heads? With hardware and without.
screw in studs and guide plates, tell him to include them in the deal or no deal. These are not the only set of heads in town.
Like I said you'll have to weight out the total cost of the project.
If you have to buy all this hard ware in addition and have some work done, You may as well buy some vortecs and the manifold
and do the mods to them. It will be about the same $'s
and the vortecs will probabily work better for you.
There are lots of good heads floating around for sale.
#61
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by F-BIRD'88
If by harware he means the valves springs locks retainers
screw in studs and guide plates, tell him to include them in the deal or no deal. These are not the only set of heads in town.
Like I said you'll have to weight out the total cost of the project.
If you have to buy all this hard ware in addition and have some work done, You may as well buy some vortecs and the manifold
and do the mods to them. It will be about the same $'s
and the vortecs will probabily work better for you.
There are lots of good heads floating around for sale.
If by harware he means the valves springs locks retainers
screw in studs and guide plates, tell him to include them in the deal or no deal. These are not the only set of heads in town.
Like I said you'll have to weight out the total cost of the project.
If you have to buy all this hard ware in addition and have some work done, You may as well buy some vortecs and the manifold
and do the mods to them. It will be about the same $'s
and the vortecs will probabily work better for you.
There are lots of good heads floating around for sale.
#62
Supreme Member
Originally posted by fattie92
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
the new cr would be 10.25:1 with 58cc heads.
Most motors like Marks Good wrench motor are not even close to 8.5:1 actual cr because the pistons are way down the bore at TDC.
Usually these motors are 7.8/8.2:1 as delivered.
thats why 58cc's heads do not result in exessive cr
when you swap them on. Your actual cr will be between 9.24
and 9.65 depending on your actual measured deck clearance.
By the time you've swept out the chamber for some bigger 1.94x 1.6 valves your chamber will be closer to 60cc's
finished. A little deck milling can bring the final cc's to what ever you want.
You can down load a good working compression ratio calc
for windows from performance trends
www.performancetrends.com
You can find typical piston specs ( dish vol's) etc from
http://www.kb-silvolite.com/
Lots of info here....
#63
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by F-BIRD'88
Usually these motors are 7.8/8.2:1 as delivered.
Usually these motors are 7.8/8.2:1 as delivered.
#64
Supreme Member
I would pay $500 to $700 (canadian) for a set of 492's
that are ready to go but unported. And not cracked!
thats $300 to $500US.
really depends on the condition, Why does he want to keep the "hardware" ? Is he trying to dump the heads?
Questions you need to ask.
I have a set of fully ported 305 heads with new 1.94x 1.50
valves 3 angle valve job hi perf springs pinned studs etc
Painted bagged ready to go for $600 canadian.
They are for sale......
thats what??..... $375+/- US money.
There are lots of good deals out there.
that are ready to go but unported. And not cracked!
thats $300 to $500US.
really depends on the condition, Why does he want to keep the "hardware" ? Is he trying to dump the heads?
Questions you need to ask.
I have a set of fully ported 305 heads with new 1.94x 1.50
valves 3 angle valve job hi perf springs pinned studs etc
Painted bagged ready to go for $600 canadian.
They are for sale......
thats what??..... $375+/- US money.
There are lots of good deals out there.
#65
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by F-BIRD'88
I would pay $500 to $700 (canadian) for a set of 492's
that are ready to go but unported. And not cracked!
thats $300 to $500US.
really depends on the condition, Why does he want to keep the "hardware" ? Is he trying to dump the heads?
Questions you need to ask.
I have a set of fully ported 305 heads with new 1.94x 1.50
valves 3 angle valve job hi perf springs pinned studs etc
Painted bagged ready to go for $600 canadian.
They are for sale......
thats what??..... $375+/- US money.
There are lots of good deals out there.
I would pay $500 to $700 (canadian) for a set of 492's
that are ready to go but unported. And not cracked!
thats $300 to $500US.
really depends on the condition, Why does he want to keep the "hardware" ? Is he trying to dump the heads?
Questions you need to ask.
I have a set of fully ported 305 heads with new 1.94x 1.50
valves 3 angle valve job hi perf springs pinned studs etc
Painted bagged ready to go for $600 canadian.
They are for sale......
thats what??..... $375+/- US money.
There are lots of good deals out there.
#66
Supreme Member
Join Date: Jun 2001
Location: Calgary, Alberta, Republic of Western Canada
Posts: 3,238
Likes: 0
Received 4 Likes
on
4 Posts
Car: 1986 Sport Coupé
Engine: 305-4v
Transmission: 700R4 and TransGo2
Originally posted by fattie92
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
how much would 305 heads raise the compression?? say i did the same hting sittingbull did, but to my LG4 416 heads, then bolted them onto my 8.5 compression 350?
#67
Supreme Member
Originally posted by Mark A Shields
yikes, that is horrible. for a non blower car.
yikes, that is horrible. for a non blower car.
And measure the deck cleareance on your motor.....
You'll see what I mean......
#68
Supreme Member
Join Date: Jul 2001
Location: Pueblo Co
Posts: 3,974
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1989 C4
Engine: L98
Transmission: 700r4
Axle/Gears: 307
Originally posted by F-BIRD'88
Hee Hee Heee!!! wait till you pull those heads off.
And measure the deck cleareance on your motor.....
You'll see what I mean......
Hee Hee Heee!!! wait till you pull those heads off.
And measure the deck cleareance on your motor.....
You'll see what I mean......
Mark, I was doing mid 13's with the old camaro uncorrected, 355/TH400, 270H cam, double springs 58cc heads 1.94 intakes, 3.42's and dual 2.5 exh.
#69
Supreme Member
What kind of springs are you gonna run Mark? you'll have a fun time tryin to open the spring pockets for larger springs on these heads because of revised and enlarged water core on these heads. Running a 1.25" spring poses no problem though.
#70
Supreme Member
Join Date: Jan 2002
Location: Addison. Il
Posts: 1,519
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by Sitting Bull
305 heads have 58 cc combustion chambers, so if you were going from the typical 76 cc 350 chambers you would definitely raise the ratio over 9:1 on a 350. You would be in the really good street performance range.
305 heads have 58 cc combustion chambers, so if you were going from the typical 76 cc 350 chambers you would definitely raise the ratio over 9:1 on a 350. You would be in the really good street performance range.
#71
Supreme Member
Originally posted by fattie92
would running nitrous on these heads be ok? also, what is the typical hp/tq increases from compression alone. is 1.0 good for 10, 20, 30, 40hp?
would running nitrous on these heads be ok? also, what is the typical hp/tq increases from compression alone. is 1.0 good for 10, 20, 30, 40hp?
there are 3 rules
1. supply enough extra fuel to burn with the nitrous. And
help in cooling the chamber and fuel charge.
2. use a fuel with a octane high enough to prevent detonation
due to the increased cylinder pressures and temp while under nos boost.
3. Only give it just enough spark advance to match the increased burn rate of the Nitrous/fuel mix. (retard the spark)
Heads that have good exhaust flow relative to intake flow,
work especially well on Nitrous.
each 1 ratio increase is worth about 2/4 % more torque and hp.
this is not linear but a general statement.
going from 7:1 to 8:1 is worth more gain than going from 12:1 to 13:1
#72
Supreme Member
Thread Starter
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by iroc22
What kind of springs are you gonna run Mark? you'll have a fun time tryin to open the spring pockets for larger springs on these heads because of revised and enlarged water core on these heads. Running a 1.25" spring poses no problem though.
What kind of springs are you gonna run Mark? you'll have a fun time tryin to open the spring pockets for larger springs on these heads because of revised and enlarged water core on these heads. Running a 1.25" spring poses no problem though.
Thread
Thread Starter
Forum
Replies
Last Post
ambainb
Camaros for Sale
11
04-25-2016 09:21 PM
gixxer92
Engine/Drivetrain/Suspension Parts for Sale
5
09-01-2015 04:32 PM