DOHC heads on LSx from a Nissan Titan...read
04-02-2015, 04:57 PM
#41
Moderator
iTrader: (4)
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,446
Received 1,838 Likes
on
1,146 Posts
That article references "specific power", which is along the lines of "horsepower per liter". By that metric, we should all have 1.6L Honda engines running 230 HP and twelve pounds of torque at 9,000 rpm in our cars.
The write even says that the specific horsepower does not necessarily win any races, so it's only bragging rights.
Look at it this way, Northstar was a 4.6L 32V engine.
The write even says that the specific horsepower does not necessarily win any races, so it's only bragging rights.
Look at it this way, Northstar was a 4.6L 32V engine.
04-02-2015, 05:25 PM
#42
That article references "specific power", which is along the lines of "horsepower per liter". By that metric, we should all have 1.6L Honda engines running 230 HP and twelve pounds of torque at 9,000 rpm in our cars.
The write even says that the specific horsepower does not necessarily win any races, so it's only bragging rights.
Look at it this way, Northstar was a 4.6L 32V engine.
The write even says that the specific horsepower does not necessarily win any races, so it's only bragging rights.
Look at it this way, Northstar was a 4.6L 32V engine.
02-04-2017, 07:43 AM
#46
TECH Senior Member
On paper it might sound ok, but in the real world when you factor in cost, complexity and added weight (to the top of the engine, giving you a higher center of gravity) and actually getting the huge heads to fit in the engine bay all for a few hp in the upper RPM range it seems totally silly unless you are just being trying to be different and don't mind losing to a pushrod LSx for a lot less money and effort.
02-04-2017, 12:25 PM
#47
Originally Posted by jimbos'ss
eventually pushrods will go the way of the dodo bird. LS motors are the last real bastion of pushrod engines in the market. I'm willing to bet the Gen V SBC motors will be DOHC with DI much like the SIDI LNF motor.
02-05-2017, 01:04 PM
#48
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
VK-56/LSx = OK Hi "GTS", I have GREAT experience with the VK-56 engine with OEM Ti-Retainers.
I worked with Butch Meyer and Carl R. to win CORR racing championships.
I manufacture O/S intake and exhaust valves that are LONGER.
I manufacture Valve Springs for the VK-56.
I manufacture ITB's @ 50mm (eight) for the VK-56.
Thus MY Camshaft set (4) is @ 600.00.
I have heads in stock with porting, cams, springs, O/S valves. (BBB)
My typical VK-56 with cams and ITB's = 485 RWHP
Would you like my help ?
I can do an EAP ?
Lance
I worked with Butch Meyer and Carl R. to win CORR racing championships.
I manufacture O/S intake and exhaust valves that are LONGER.
I manufacture Valve Springs for the VK-56.
I manufacture ITB's @ 50mm (eight) for the VK-56.
Thus MY Camshaft set (4) is @ 600.00.
I have heads in stock with porting, cams, springs, O/S valves. (BBB)
My typical VK-56 with cams and ITB's = 485 RWHP
Would you like my help ?
I can do an EAP ?
Lance
02-05-2017, 08:32 PM
#49
Teching In
Join Date: Dec 2016
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Hi "GTS", I have GREAT experience with the VK-56 engine with OEM Ti-Retainers.
I worked with Butch Meyer and Carl R. to win CORR racing championships.
I manufacture O/S intake and exhaust valves that are LONGER.
I manufacture Valve Springs for the VK-56.
I manufacture ITB's @ 50mm (eight) for the VK-56.
Thus MY Camshaft set (4) is @ 600.00.
I have heads in stock with porting, cams, springs, O/S valves. (BBB)
My typical VK-56 with cams and ITB's = 485 RWHP
Would you like my help ?
I can do an EAP ?
Lance
I worked with Butch Meyer and Carl R. to win CORR racing championships.
I manufacture O/S intake and exhaust valves that are LONGER.
I manufacture Valve Springs for the VK-56.
I manufacture ITB's @ 50mm (eight) for the VK-56.
Thus MY Camshaft set (4) is @ 600.00.
I have heads in stock with porting, cams, springs, O/S valves. (BBB)
My typical VK-56 with cams and ITB's = 485 RWHP
Would you like my help ?
I can do an EAP ?
Lance
02-05-2017, 08:46 PM
#50
Teching In
Join Date: Dec 2016
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Pretty pointless actually.
On paper it might sound ok, but in the real world when you factor in cost, complexity and added weight (to the top of the engine, giving you a higher center of gravity) and actually getting the huge heads to fit in the engine bay all for a few hp in the upper RPM range it seems totally silly unless you are just being trying to be different and don't mind losing to a pushrod LSx for a lot less money and effort.
On paper it might sound ok, but in the real world when you factor in cost, complexity and added weight (to the top of the engine, giving you a higher center of gravity) and actually getting the huge heads to fit in the engine bay all for a few hp in the upper RPM range it seems totally silly unless you are just being trying to be different and don't mind losing to a pushrod LSx for a lot less money and effort.
can we agree to this?.. the only limitation to power is how much air and fuel in the proper ratio you can get in the cylinder and combust it efficiently.. there is no replacement for displacement with the given exception of boost, nitrous, or raising combustion efficiency. Well guys air flow numbers don't lie. Here are flow numbers on "useless dohc heads"
the bright grey line is a set of ls3 heads for comparison
Last edited by Gtslo04; 02-05-2017 at 08:49 PM. Reason: Additional info on flow chart
02-06-2017, 10:36 AM
#51
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
DFV LS Head Conversion Hi GTS, sounds like a "team" effort.
I use SW, I can create the files.
Do you use Master Cam ?
I would like to send you some pictures of the drive on the VK-56.
I would use a Wegner WP, a "drive" similar to Casey's SC kit.
EAP model @ 740HP (8000RPM) (337 CID)
Sounds like you are interested ?
Lance
I use SW, I can create the files.
Do you use Master Cam ?
I would like to send you some pictures of the drive on the VK-56.
I would use a Wegner WP, a "drive" similar to Casey's SC kit.
EAP model @ 740HP (8000RPM) (337 CID)
Sounds like you are interested ?
Lance
05-03-2020, 08:25 AM
#52
10 Second Club
05-03-2020, 10:34 AM
#53
TECH Senior Member
05-03-2020, 12:59 PM
#55
The DOHC LT5 engine while exceptional added about one hundred pounds of weight. It also required an additional two hundred additional pounds of weight gain in the car with other equipment etc compared to the LT4.
I think GM Powertrain/Propulsion call the concept Power Density. Small package with low weight that makes max power. In other words best power for weight and volume. Often the smaller lighter push rod engines have the best power density.
I doubt GM will go DoHC crazy because electric powered cars are on the horizon as the power train of choice.
Last edited by 99 Black Bird T/A; 05-05-2020 at 04:07 AM.
The following users liked this post:
G Atsma (05-03-2020)
05-04-2020, 01:37 PM
#56
But if I recall correctly, there are F1 engines that don't use a camshaft or mechanical timing mechanisms at all. They had a crazy electronic solenoid thing on each valve and it was 100% computer controlled. No spring even.
Necessity is it the mother of invention though. The reason we still have pushrods in LS engines is because it's economically viable to produce and it just plain works. There is no reason to go to DOHC unless you get something more out of it. We have pushrods going to 8000rpm which no one thought practical 20+ years ago. But they made it work and it's cheap, so it stays. I'm not sure what an over head cam can offer if you can't gain any RPM or engine life. Timing belts are the devils engine part IMO.
Last edited by LetsTurboSomething; 05-04-2020 at 01:42 PM.
05-04-2020, 02:30 PM
#57
11 Second Club
iTrader: (3)
05-04-2020, 04:10 PM
#58
TECH Senior Member
Overhead cam does give the crank more room for longer stroke, but it increases weight, dimensions (height and width).
The comment above regarding power density is very relevant.
The comment above regarding power density is very relevant.
05-05-2020, 07:52 AM
#59
Moderator
iTrader: (4)
Join Date: Jul 2014
Location: My own internal universe
Posts: 10,446
Received 1,838 Likes
on
1,146 Posts
What an old thread...
But if I recall correctly, there are F1 engines that don't use a camshaft or mechanical timing mechanisms at all. They had a crazy electronic solenoid thing on each valve and it was 100% computer controlled. No spring even.
Necessity is it the mother of invention though. The reason we still have pushrods in LS engines is because it's economically viable to produce and it just plain works. There is no reason to go to DOHC unless you get something more out of it. We have pushrods going to 8000rpm which no one thought practical 20+ years ago. But they made it work and it's cheap, so it stays. I'm not sure what an over head cam can offer if you can't gain any RPM or engine life. Timing belts are the devils engine part IMO.
But if I recall correctly, there are F1 engines that don't use a camshaft or mechanical timing mechanisms at all. They had a crazy electronic solenoid thing on each valve and it was 100% computer controlled. No spring even.
Necessity is it the mother of invention though. The reason we still have pushrods in LS engines is because it's economically viable to produce and it just plain works. There is no reason to go to DOHC unless you get something more out of it. We have pushrods going to 8000rpm which no one thought practical 20+ years ago. But they made it work and it's cheap, so it stays. I'm not sure what an over head cam can offer if you can't gain any RPM or engine life. Timing belts are the devils engine part IMO.
I can tell you I've had three engines go where I had to replace all the valves, and all three were overhead cam. One was a belt and two were chains. The belt broke. The other two were the same car. Chain had stretched and jumped a tooth. I repaired it. new chain, etc. 20k miles later did it again. That car is now rebar I think.
Power density FTW. One of the reasons LS swaps are so prevalent (possibly even the main reason) is power density. You can fit it into almost anything - I mean ****, if it can fit in a S10... And name another small block that goes to 440 CI
05-05-2020, 06:27 PM
#60
ModSquad
iTrader: (6)
FreeValve. I want to say koenigsegg developed it. The idea is awesome. VVT plus variable duration. Wouldn't even need gears at the track lol. Now if only Koenigsegg would develop Half Life 3....
I can tell you I've had three engines go where I had to replace all the valves, and all three were overhead cam. One was a belt and two were chains. The belt broke. The other two were the same car. Chain had stretched and jumped a tooth. I repaired it. new chain, etc. 20k miles later did it again. That car is now rebar I think.
Power density FTW. One of the reasons LS swaps are so prevalent (possibly even the main reason) is power density. You can fit it into almost anything - I mean ****, if it can fit in a S10... And name another small block that goes to 440 CI
I can tell you I've had three engines go where I had to replace all the valves, and all three were overhead cam. One was a belt and two were chains. The belt broke. The other two were the same car. Chain had stretched and jumped a tooth. I repaired it. new chain, etc. 20k miles later did it again. That car is now rebar I think.
Power density FTW. One of the reasons LS swaps are so prevalent (possibly even the main reason) is power density. You can fit it into almost anything - I mean ****, if it can fit in a S10... And name another small block that goes to 440 CI