Vq35HR block on DE heads
11-25-2010, 09:38 PM
#1
Vq35HR block on DE heads
Hey guys, I was just browsing around different setups and I noticed nobody had ever discussed this. (this is just a little throw around of ideas for the sake of entertainment right now I have no plans to expand on this idea lol). All I've seen (with search results) is the discussion of putting HR heads on a DE block, but from what I can tell, the HR block should be stronger. The HR has an 8mm longer rod length, a taller block, different cooling passages, and an 'improved' two piece block design.
Now, when I look at the flow dynamics of the DE, its more than adequate, and really isn't the limitation of the VQ, hell some cams, new valve springs and an intake manifold and you can flow 700+whp (yes that is subjective to parts, tune and turbo kit... I'm just talking general VE). The real limitation is the block, which is open deck and aluminum. If the HR block is stronger, wouldn't it be smart to bolt up an HR block to a DE head? Yes you'd run into some problems; a taller hood would be in order, and the HR has a diff trans bolt pattern (and whatever timing chain/cam timing **** would need to be done aside of that), but if you are running deep for 1000+hp wouldn't it make sense to buy a HR block? Especially if you are already going to build a separate block for the car.
Inputs? Is this possible, and or a valid idea? lol this is purely discussion for the sake of discussion. (And I did google/site search this topic). And yes it is easier to get an HR block by buying a HR car.
EDIT:
And what are your opinions on long rod vs short rod? Its a big debate in the Honda world...
Now, when I look at the flow dynamics of the DE, its more than adequate, and really isn't the limitation of the VQ, hell some cams, new valve springs and an intake manifold and you can flow 700+whp (yes that is subjective to parts, tune and turbo kit... I'm just talking general VE). The real limitation is the block, which is open deck and aluminum. If the HR block is stronger, wouldn't it be smart to bolt up an HR block to a DE head? Yes you'd run into some problems; a taller hood would be in order, and the HR has a diff trans bolt pattern (and whatever timing chain/cam timing **** would need to be done aside of that), but if you are running deep for 1000+hp wouldn't it make sense to buy a HR block? Especially if you are already going to build a separate block for the car.
Inputs? Is this possible, and or a valid idea? lol this is purely discussion for the sake of discussion. (And I did google/site search this topic). And yes it is easier to get an HR block by buying a HR car.
EDIT:
And what are your opinions on long rod vs short rod? Its a big debate in the Honda world...
Last edited by Resmarted; 11-25-2010 at 09:40 PM.
11-26-2010, 06:18 AM
#2
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The HR motor is better all around. The heads do flow quite a bit more tan DE heads do as well. IF you did put DE heads on an HR block, you would need a custom intake manifold from the heads up because the deck height change spreads the cylinder heads apart and also the port shape and bolt to port location is different.
IF you were going turbo and wanted A LOT of power, then yes, the block would be worth it for strength.
If you were doing an NA build, i thiink the HR heads on a DE block would be better than the HR block with DE heads.
Short rod VS long rod is and always will be a long, very long, debate. Are you asking which makes more power, or which has proven more reliability? a short rod application CAN make more power than a long rod by increasing piston speed which can in SOME applications increase cylinder fill... BUT with a shorter rod, you increase rod movement across the rod journal which increases friction and heat which CAN effect longevity and wear and tear on the motor.
My personal opinion, if you are going for maximum power and do not care about longevity, I.E. you just do street driving or drag racing, then dont really worry about rod/stroke ratio, it wont really affect you unless you are at a very extreme end of it. IF you are road racing or doing track days, then I would highly recommend sticking to a longer rod setup for longevity...
This debate is very very very VERY lengthy and gets pretty far in and over most peoples heads..
IF you were going turbo and wanted A LOT of power, then yes, the block would be worth it for strength.
If you were doing an NA build, i thiink the HR heads on a DE block would be better than the HR block with DE heads.
Short rod VS long rod is and always will be a long, very long, debate. Are you asking which makes more power, or which has proven more reliability? a short rod application CAN make more power than a long rod by increasing piston speed which can in SOME applications increase cylinder fill... BUT with a shorter rod, you increase rod movement across the rod journal which increases friction and heat which CAN effect longevity and wear and tear on the motor.
My personal opinion, if you are going for maximum power and do not care about longevity, I.E. you just do street driving or drag racing, then dont really worry about rod/stroke ratio, it wont really affect you unless you are at a very extreme end of it. IF you are road racing or doing track days, then I would highly recommend sticking to a longer rod setup for longevity...
This debate is very very very VERY lengthy and gets pretty far in and over most peoples heads..
11-26-2010, 12:13 PM
#3
The HR motor is better all around. The heads do flow quite a bit more tan DE heads do as well. IF you did put DE heads on an HR block, you would need a custom intake manifold from the heads up because the deck height change spreads the cylinder heads apart and also the port shape and bolt to port location is different.
IF you were going turbo and wanted A LOT of power, then yes, the block would be worth it for strength.
If you were doing an NA build, i thiink the HR heads on a DE block would be better than the HR block with DE heads.
Short rod VS long rod is and always will be a long, very long, debate. Are you asking which makes more power, or which has proven more reliability? a short rod application CAN make more power than a long rod by increasing piston speed which can in SOME applications increase cylinder fill... BUT with a shorter rod, you increase rod movement across the rod journal which increases friction and heat which CAN effect longevity and wear and tear on the motor.
My personal opinion, if you are going for maximum power and do not care about longevity, I.E. you just do street driving or drag racing, then dont really worry about rod/stroke ratio, it wont really affect you unless you are at a very extreme end of it. IF you are road racing or doing track days, then I would highly recommend sticking to a longer rod setup for longevity...
This debate is very very very VERY lengthy and gets pretty far in and over most peoples heads..
IF you were going turbo and wanted A LOT of power, then yes, the block would be worth it for strength.
If you were doing an NA build, i thiink the HR heads on a DE block would be better than the HR block with DE heads.
Short rod VS long rod is and always will be a long, very long, debate. Are you asking which makes more power, or which has proven more reliability? a short rod application CAN make more power than a long rod by increasing piston speed which can in SOME applications increase cylinder fill... BUT with a shorter rod, you increase rod movement across the rod journal which increases friction and heat which CAN effect longevity and wear and tear on the motor.
My personal opinion, if you are going for maximum power and do not care about longevity, I.E. you just do street driving or drag racing, then dont really worry about rod/stroke ratio, it wont really affect you unless you are at a very extreme end of it. IF you are road racing or doing track days, then I would highly recommend sticking to a longer rod setup for longevity...
This debate is very very very VERY lengthy and gets pretty far in and over most peoples heads..
I'm not too sure about what you are saying with the intake manifold; are you essentially saying the cylinders will be in a different place (in reference to the heads)???? A custom intake manifold is THAT big of a deal to me, I'd be pretty tempted to make a custom front entrance manifold with q45 throttle body if i was doing my "dream build" anyway.
I'm just suggesting this as a better alternative to sleeving, and if its cheaper than Nikasils, then people should seriously look at this...
Maybe I should have posted this in the FI forum...
EDIT:
to me the head of the HR isn't as wanted as the actual block (and it is likely much more valuable). The DE head again (even if it is out flowed by the HR) flows plenty well; the head doesn't seem to be a limiting factor. The actual cylinder walls seem to be the limiting factor, which the HR should have stronger... HR block could be cheaper than sleeving a DE block, and more reliable (provided it is assembled correctly).
Last edited by Resmarted; 11-26-2010 at 12:20 PM.
11-26-2010, 06:49 PM
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I already have my answer sided on short rod, mainly due to the revving characteristics of a short rod (response and max rpm). Although long rod has the better short stroke 'longevity'. But the biggest reason why under square wins to me, is the fact that at any time on power stroke, the short rod will generate a greater force on the crank pin.
I'm not too sure about what you are saying with the intake manifold; are you essentially saying the cylinders will be in a different place (in reference to the heads)???? A custom intake manifold is THAT big of a deal to me, I'd be pretty tempted to make a custom front entrance manifold with q45 throttle body if i was doing my "dream build" anyway.
I'm just suggesting this as a better alternative to sleeving, and if its cheaper than Nikasils, then people should seriously look at this...
Maybe I should have posted this in the FI forum...
EDIT:
to me the head of the HR isn't as wanted as the actual block (and it is likely much more valuable). The DE head again (even if it is out flowed by the HR) flows plenty well; the head doesn't seem to be a limiting factor. The actual cylinder walls seem to be the limiting factor, which the HR should have stronger... HR block could be cheaper than sleeving a DE block, and more reliable (provided it is assembled correctly).
I'm not too sure about what you are saying with the intake manifold; are you essentially saying the cylinders will be in a different place (in reference to the heads)???? A custom intake manifold is THAT big of a deal to me, I'd be pretty tempted to make a custom front entrance manifold with q45 throttle body if i was doing my "dream build" anyway.
I'm just suggesting this as a better alternative to sleeving, and if its cheaper than Nikasils, then people should seriously look at this...
Maybe I should have posted this in the FI forum...
EDIT:
to me the head of the HR isn't as wanted as the actual block (and it is likely much more valuable). The DE head again (even if it is out flowed by the HR) flows plenty well; the head doesn't seem to be a limiting factor. The actual cylinder walls seem to be the limiting factor, which the HR should have stronger... HR block could be cheaper than sleeving a DE block, and more reliable (provided it is assembled correctly).
As for the intake manifold, with the HR block, the deck height is roughly 8mm taller on each bank than the DE block. With the heads raised up higher, the spacing between the heads increases. Meaning that the bolt spacing from the right head to the left head wiill probably increase by about 8mm and thus the stock DE intake manifold will be 8mm too narrow and will not bolt on. You could possibly make a custom one, and or cut the LIM and make your own piece from parts of the stock one or so on....
Last edited by gt20ir; 11-26-2010 at 06:50 PM.
11-26-2010, 10:31 PM
#5
Yes, I do agree about the short rod making more power. been there and built many K24 Honda drag motors that run stupid high piston speeds with 1.35 R/S ratio's and over 6500fpm piston speeds.... they dont last forever, but they make stupid power...
As for the intake manifold, with the HR block, the deck height is roughly 8mm taller on each bank than the DE block. With the heads raised up higher, the spacing between the heads increases. Meaning that the bolt spacing from the right head to the left head wiill probably increase by about 8mm and thus the stock DE intake manifold will be 8mm too narrow and will not bolt on. You could possibly make a custom one, and or cut the LIM and make your own piece from parts of the stock one or so on....
As for the intake manifold, with the HR block, the deck height is roughly 8mm taller on each bank than the DE block. With the heads raised up higher, the spacing between the heads increases. Meaning that the bolt spacing from the right head to the left head wiill probably increase by about 8mm and thus the stock DE intake manifold will be 8mm too narrow and will not bolt on. You could possibly make a custom one, and or cut the LIM and make your own piece from parts of the stock one or so on....
Ah, I see what you are saying now.
11-27-2010, 08:34 AM
#6
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stock 87x99.
Most are 89-90mm bore and 99mm stroke,
Many are 89mm x 103mm stroke for a 2.6L
Nothing I would do for road racing or long term street as they tear bearings up pretty fast.
I do understand why you would want to run the DE heads because of the cams and other sensors working with your current setup, it may be cheapest though to buy a complete long block and part it out and keep what you want.
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