![]() |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
![]() ![]() |
![]() |
Dave_Darling |
![]()
Post
#21
|
914 Idiot ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 15,255 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California ![]() ![]() |
Part of the disagreement would appear to be that you guys are using two different definitions of "less heat". I believe that Jake is saying that less heat was staying in the heads and in the oil, while DB was referring to the overall heat produced by the engine, including those and heat being radiated away and heat coming out the exhaust, etc.
Physics is physics; to make more power you burn more fuel and produce more total heat. But that heat does not have to go into the heads and into the oil; it can leave through the exhaust among other things. And my guess (just a guess!) is that this is how both of you can be right at the same time... --DD |
Jake Raby |
![]()
Post
#22
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
Part of the disagreement would appear to be that you guys are using two different definitions of "less heat". I believe that Jake is saying that less heat was staying in the heads and in the oil, while DB was referring to the overall heat produced by the engine, including those and heat being radiated away and heat coming out the exhaust, etc. Physics is physics; to make more power you burn more fuel and produce more total heat. But that heat does not have to go into the heads and into the oil; it can leave through the exhaust among other things. And my guess (just a guess!) is that this is how both of you can be right at the same time... --DD This is why people disagree on forums, so often. If bigger engines melted down, no matter what, we'd all be driving around in 3 cylinder Geo Metros. |
DBCooper |
![]()
Post
#23
|
14's in the 13's with ATTITUDE ![]() ![]() ![]() ![]() Group: Members Posts: 3,079 Joined: 25-August 04 From: Dazed and Confused Member No.: 2,618 Region Association: Northern California ![]() |
I never said that more power does not increase more heat.... You didn't say that? I could have sworn... oh, yeah, here it is, right here: QUOTE . Just remember that HP=heat. Not if it adds efficiency. All that said, it's all in the combo- yet it may take you over 1,000 tries to learn that. One thing is for sure, you damn sure won't learn it sitting in front of a monitor and keyboard. Jake, any competent mechanic learns early on that matching parts is the key to efficiency. I'm retired now so I learned that long before you built your first engine. And my teacher was a guy who learned that same lesson before I was born, so no news there. Getting the combinations right? That takes longer, no question, and that's exactly the question posed by the original poster about optimum combinations for a 2270. So you're the expert, do you have any suggestions for him? I mean other than just buying parts from your store? You're right, Dave, two different things that are the same. If someone's paying a whole lot of money for more horsepower one has to assume they're going to use it. Is any other assumption reasonable? If you have twice the horsepower (and use it) you'll generate twice the heat, meaning you need to dissipate it. No question there either, right? Not going to create enough heat to hurt anything? Perhaps, since no one's melting down Jake's engines. But that in no way means they generate less heat, as long as they burn fuel that potential's all still there, they apparently just aren't being used hard enough to hurt anything. And of course any marginal additional heat generated is being managed, so good job Jake and God Bless Joe Locicero. |
gereed75 |
![]()
Post
#24
|
Senior Member ![]() ![]() ![]() Group: Members Posts: 1,388 Joined: 19-March 13 From: Pittsburgh PA Member No.: 15,674 Region Association: North East States ![]() ![]() |
not to jump in (there are plenty of people already in the skirmish) but one factor that is part of what Jake is saying regarding efficiency (I think) is efficiency of the system, not necessarily combustion effciency---- Better cooling, better heat transfer, less friction generated heat,etc etc all lend to improved system efficiency, improved heat dissipation and cooler temps.
Part better system effciency and part more effective system. Net effect is cooler temps than a less effective system making the same HP. Pax and out |
Jake Raby |
![]()
Post
#25
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
QUOTE Jake, any competent mechanic learns early on that matching parts is the key to efficiency. And some never do. QUOTE I'm retired now so I learned that long before you built your first engine. And my teacher was a guy who learned that same lesson before I was born, so no news there. I have guys that have been doing this longer than I have been alive attend my Porsche engine classes every month, somewhere across North America. QUOTE Getting the combinations right? That takes longer, no question, and that's exactly the question posed by the original poster about optimum combinations for a 2270. The issue is the constantly changing factors that impact the engine. Fuel, oil, environmental conditions and etc make it impossible to have a perfect combination thats perfect for everyone for years and years. As I have finally based my engines from one combination for 2015, and increased displacement to 2.4L, for all, we have had to take an exceptional amount of time to develop one well oiled machine, but cam CR, and head alterations still remain a variable that each engine must be altered. QUOTE So you're the expert, do you have any suggestions for him? 78.4, 5.325" rod, KB 96mm pistons, Hastings rings. Web 163/86B cam on 104* LC, ground on a 1.065" BC, and he can start his valve train geometry with a 27.1Cm pushrod. Thats a generic combo that assembles easily, and with a 180CFM 76% head will make 140HP at 9:1 CR. Thats the combo that I first started using in the mid 90s with custom parts, that are now so generic that they can be bought on eBay, after I was ripped off and the parts when to China. Thats what happens. QUOTE I mean other than just buying parts from your store? What store? I don't have a store, its been a year since I had a store, I got tired of dealing with people and sold the store to LN. I went back to only building engines, and primarily doing R&D work for other companies, or for new products. I've submitted 4 Patent Applications this year alone, the most recent was Monday, and it was for yet another special tool. Parts aren't my thing, and I never should have created the store, because it held me back more than anything. Thats water under the bridge~ QUOTE You're right, Dave, two different things that are the same. If someone's paying a whole lot of money for more horsepower one has to assume they're going to use it. Is any other assumption reasonable? Use it, certainly, but for how long? Its not reasonable to drive around at WOT on the street in today's world, and thats the reason why the engine won't ever get heat soaked. I did the testing of my 3 liter engine up and down the side of a mountain near me that has a long, continuous 5% grade, and I did the WOT runs in 5th gear with a tall tire and a ZD 5th gear, for max load. On a 90 degree day we couldn't even get the CHT to pass 350F for more than 45 seconds before we'd crest the hill and the temps would drop. These engines don't begin to heat soak till 375-400F and with Nickies not until 425F. QUOTE If you have twice the horsepower (and use it) you'll generate twice the heat, meaning you need to dissipate it. No question there either, right? Nope. Let's say that your engine produces 200HP @ 6,000 RPM, which is basically double the factory 2.0/914 output. Where can you effectively drive that car in the USA and maintain 6,000 RPM continuously? QUOTE Not going to create enough heat to hurt anything? Perhaps, since no one's melting down Jake's engines. You'll kill yourself, before you find out. QUOTE But that in no way means they generate less heat, as long as they burn fuel that potential's all still there, they apparently just aren't being used hard enough to hurt anything. Is 30 minutes at WOT continuous, with a 9,000 RPM at 14:1while making north of 185HP from an 1800cc T4 considered "being used hard enough"? That engine never gets to 400CHT and it only touched 400 on the CHT gauge once, that was a day at Road Atlanta when track temps were 136 in the middle of July. QUOTE And of course any marginal additional heat generated is being managed, so good job Jake and God Bless Joe Locicero. I seldom build a 914 engine that uses the DTM system designed by Joe, even though we did make a 914 specific version of it. The stock cooling system is fine on engines up to 2.4L without Nickies, and clear to 3 liters with Nickies. Add a single Setrab oil cooler and they are fine eve on the track, to well over 200HP with one set of mods to the blower housing and the cooling fan. |
r_towle |
![]()
Post
#26
|
Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States ![]() ![]() |
My advice is to make so much power that all of it is never, ever needed. I am sorry but I was always under the impression that you don't have enough power until you can do a burn out from the exit of one corner all the way to the entrance of the next corner. Never is a very powerful word that I could not comply with and still be a car guy. |
Jake Raby |
![]()
Post
#27
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
My advice is to make so much power that all of it is never, ever needed. I am sorry but I was always under the impression that you don't have enough power until you can do a burn out from the exit of one corner all the way to the entrance of the next corner. Never is a very powerful word that I could not comply with and still be a car guy. And since you are losing traction during that burnout, engine load is decreased and the engine temps would take longer to create heat soak. Until that car could do a burnout constantly, for hundreds of miles, it still doesn't have enough power... Or rubber, or traction. Around 1400 engines have left my facility. These are as early as a pre A 356, and as late as a 2014 Cayman S with everything in between from 4 cam Fuhrmann Carrera through 9a1. To date I have never, not once ever had anyone state that they didn't have enough power after my processes were completed. |
r_towle |
![]()
Post
#28
|
Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States ![]() ![]() |
My advice is to make so much power that all of it is never, ever needed. I am sorry but I was always under the impression that you don't have enough power until you can do a burn out from the exit of one corner all the way to the entrance of the next corner. Never is a very powerful word that I could not comply with and still be a car guy. And since you are losing traction during that burnout, engine load is decreased and the engine temps would take longer to create heat soak. Until that car could do a burnout constantly, for hundreds of miles, it still doesn't have enough power... Or rubber, or traction. Around 1400 engines have left my facility. These are as early as a pre A 356, and as late as a 2014 Cayman S with everything in between from 4 cam Fuhrmann Carrera through 9a1. To date I have never, not once ever had anyone state that they didn't have enough power after my processes were completed. Actually, I was trying to lighten the mood Jake. It was a joke. I suppose we could bring in the East Coast thread killing squad.... I do thank you for posting details on an engine combo that would help a lot of folks out with a basic and fun 2270 . Honestly, thanks for sharing that. Keep building and share when you can, that is what makes these forums great. Rich |
Jake Raby |
![]()
Post
#29
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
I knew what you were doing.. No biggie.
I bet that 2270 combo has already been copied and pasted by 20 people since I posted it. It takes a lot more than just the recipe to build a good engine, for one, you may never know just how long it needs to simmer before you can put it onto the plate. Hell, what we've done has been copied so much, I may as well just give it away and save the copy cats the hassle of buying an engine and dissecting it, then farming out all the parts to be made at a sweat shop in Thailand. |
r_towle |
![]()
Post
#30
|
Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States ![]() ![]() |
This is your business, everyone knows that.
For many of us, this is fun...it's therapy, it's a hobby. Let other build a motor from scratch, enjoy it, and be proud to have done it. rich |
Jake Raby |
![]()
Post
#31
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
This is your business, everyone knows that. For many of us, this is fun...it's therapy, it's a hobby. Let other build a motor from scratch, enjoy it, and be proud to have done it. rich It's the same for me... I personally don't HAVE to build engines anymore, but I do anyway, for the same reasons that you stated. When things work well it's therapy, when you screw up or don't know what you don't know, it gets real. |
JimN73 |
![]()
Post
#32
|
Senior Member ![]() ![]() ![]() Group: Members Posts: 535 Joined: 6-October 07 From: Gig Harbor Member No.: 8,192 Region Association: Pacific Northwest ![]() |
This thread brings up a couple of things that I have wondered about, so maybe someone can answer the questions.
At about what point do you move from 40 to 44 to 48 IDFs, assuming that carbs are being used? Considering displacement, cam, projected usage and other variables. Same question for increases in valve sizes, both intake and exhaust. Thanks for the education. |
r_towle |
![]()
Post
#33
|
Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States ![]() ![]() |
This is your business, everyone knows that. For many of us, this is fun...it's therapy, it's a hobby. Let other build a motor from scratch, enjoy it, and be proud to have done it. rich It's the same for me... I personally don't HAVE to build engines anymore, but I do anyway, for the same reasons that you stated. When things work well it's therapy, when you screw up or don't know what you don't know, it gets real. But the real part IS the therapy, at least for me. Solving the problems, finding ths issue, I know you like that.... For me, that is the fun part, not bolting parts together.. |
Jake Raby |
![]()
Post
#34
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
This is your business, everyone knows that. For many of us, this is fun...it's therapy, it's a hobby. Let other build a motor from scratch, enjoy it, and be proud to have done it. rich It's the same for me... I personally don't HAVE to build engines anymore, but I do anyway, for the same reasons that you stated. When things work well it's therapy, when you screw up or don't know what you don't know, it gets real. But the real part IS the therapy, at least for me. Solving the problems, finding ths issue, I know you like that.... For me, that is the fun part, not bolting parts together.. People are different. I see them give up all the time after they expect things to go smooth and be straight forward, but then they aren't. Keyboards have ruined people and have dulled their spirit to stick with things till they get a positive result. Unless something is difficult, beyond normal comprehension, I care nothing about having any part of it.. Our breed is dying. That said, I don't move to a 48mm carb until I have at least 2.7L of displacement to deal with, often times the larger carb will make less power, because you can't ever optimize it. Bigger is very seldom better. |
r_towle |
![]()
Post
#35
|
Custom Member ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States ![]() ![]() |
This is your business, everyone knows that. For many of us, this is fun...it's therapy, it's a hobby. Let other build a motor from scratch, enjoy it, and be proud to have done it. rich It's the same for me... I personally don't HAVE to build engines anymore, but I do anyway, for the same reasons that you stated. When things work well it's therapy, when you screw up or don't know what you don't know, it gets real. But the real part IS the therapy, at least for me. Solving the problems, finding ths issue, I know you like that.... For me, that is the fun part, not bolting parts together.. People are different. I see them give up all the time after they expect things to go smooth and be straight forward, but then they aren't. Keyboards have ruined people and have dulled their spirit to stick with things till they get a positive result. Unless something is difficult, beyond normal comprehension, I care nothing about having any part of it.. Our breed is dying. That said, I don't move to a 48mm carb until I have at least 2.7L of displacement to deal with, often times the larger carb will make less power, because you can't ever optimize it. Bigger is very seldom better. To go with a trend... There is a much wider set of parts, support, and just plain cool looks with the 48 IDA carbs. Is there a way to make them work? Like smaller ventures? I ask because the wide assortment of cool looking ventures etc makes me want to go with these carbs, and yes, it may be bling... Again, it's a can,t be done thing that makes me want to try (IMG:style_emoticons/default/smile.gif) You inspired me to get Djet to run on a 2.4..... Just wanted to see if I could... Yes, it's not optimal, but it works.... Rich |
Woody |
![]()
Post
#36
|
Sandbox Rabblerouser and head toilet scrubber ![]() ![]() ![]() ![]() Group: Members Posts: 3,858 Joined: 28-December 10 From: San Antonio Texas Member No.: 12,530 Region Association: Southwest Region ![]() |
If you built a 2.4 with huge bore and a small stroke the 48s would probably work better than a smaller bore with a longer stroke. With the longer stroke you have more time to fill the cylinder with a smaller carb. You'll get less intake charge velocity with the larger carb. I believe that is what Jake is touching on.
|
Jake Raby |
![]()
Post
#37
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
Here's the 2.6L MassIVe engine thats in my 356. It has LE 220 heads, 10:1, roller camshaft/ lifters and lots of other tricks. It optimized fairly well with the 52mm Bologna IDAs pictured, with a 40mm venturi. it made more power on the dyno with 45mm Dellortos with a 42mm venturi.
That said, these carbs will not be on the car for that long, because like all IDAs, even with a 3rd progression hole they lack serious drivability. I've had these carbs for over 25 years, and I wanted to use them for the 356, but I am seriously not about bling, and much prefer the Dells. I've only had one T4 like an IDA better than an IDF or DRLA, that was the 3 liter twin plug roller engine in Beth's vert that made 250HP on 89 octane fuel, using these same 52mm IDAs. I can't sleep well at night if something isn't optimized, I don't give a damn about bling. Attached thumbnail(s) ![]() |
Jake Raby |
![]()
Post
#38
|
Engine Surgeon ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States ![]() |
|
McMark |
![]()
Post
#39
|
914 Freak! ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Retired Admin Posts: 20,180 Joined: 13-March 03 From: Grand Rapids, MI Member No.: 419 Region Association: None ![]() |
I knew there was a reason I didn't open this thread earlier. Now I wish I hadn't. (IMG:style_emoticons/default/yawn.gif)
|
Woody |
![]()
Post
#40
|
Sandbox Rabblerouser and head toilet scrubber ![]() ![]() ![]() ![]() Group: Members Posts: 3,858 Joined: 28-December 10 From: San Antonio Texas Member No.: 12,530 Region Association: Southwest Region ![]() |
I knew there was a reason I didn't open this thread earlier. Now I wish I hadn't. (IMG:style_emoticons/default/yawn.gif) (IMG:style_emoticons/default/bye1.gif) |
![]() ![]() |
![]() |
Lo-Fi Version | Time is now: 16th September 2025 - 09:43 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |