HP vs $$$ for SC engine mod
Instructor
Joined: Jun 2001
Posts: 148
Likes: 0
From: Newport Beach, CA
I have a 78SC with the stock 3.0. I have stayed away from engine mods because it takes alot of money to get a little more HP out of these motors. Some improvements that I made, which have been relatively inexpensive, and have really increased the usable power of the stock 3.0 are pre-74 exhaust manifolds w/a factory sport muffler; dropping about 280 lbs of weight, and a good suspension set up. Of course the car has the Carrera tensioners and pop-off valve, but I consider these necessities and not performance mods.
I was also wondering about the 7:13 tranaxle. since gearing really can give seat of the pants improvements. Can a early transaxle with the 7:13 R&P be swapped into the SC easily? Will it be just as reliable as the 915/63 trans with the R&P swapped for the 3.0?
I was also wondering about the 7:13 tranaxle. since gearing really can give seat of the pants improvements. Can a early transaxle with the 7:13 R&P be swapped into the SC easily? Will it be just as reliable as the 915/63 trans with the R&P swapped for the 3.0?
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From: California, MD
901 trans not a good idea -- think you meant 7:31. Although I would like more information on Steve's direction. Move 2nd & 3rd up and 4th and 5th down or 2nd through 4th up?
Advanced
Joined: Apr 2002
Posts: 54
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From: Providence, RI
I'd like to ask to borrow someone's $.02 on this issue as well. I'm in a similar predicament as Dennis, but in a way - more so. I recently lost a cylinder on my 2.7 and have decided to upgrade. I auto-x religiously and I'm going to DE next season.
I am also planning to keep my car for life, and love the lightness and simplicity of my car.
I have been seriously looking at the 3.6 swap(+/- 280HP). After reading Rennlist archives on this topic, it seems "Instant-G" is the way to go. That would be a no-brainer for me but for the $13K price tag. I know I can bring this down a little by doing the install myself, etc. but that's a lot of cake! <img src="graemlins/crying.gif" border="0" alt="[crying]" />
My other dilemma with this is I have already put many upgrades in my now dead 2.7: SSI's, sport muffler, hydrolic tensioners, turbo valve covers.
Would I be able to swap these parts into a 3.0? Would I be happy with the 3.0 power (+/- 200HP)? I was always very dissappointed with the power of the 2.7(+/- 180 HP).
Should Dennis and I go for the big power and starve or settle for the 3.0 and get on with life? <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />
TIA for any advice
Chris Tuck
'75 911s 2.25L
I am also planning to keep my car for life, and love the lightness and simplicity of my car.
I have been seriously looking at the 3.6 swap(+/- 280HP). After reading Rennlist archives on this topic, it seems "Instant-G" is the way to go. That would be a no-brainer for me but for the $13K price tag. I know I can bring this down a little by doing the install myself, etc. but that's a lot of cake! <img src="graemlins/crying.gif" border="0" alt="[crying]" />
My other dilemma with this is I have already put many upgrades in my now dead 2.7: SSI's, sport muffler, hydrolic tensioners, turbo valve covers.
Would I be able to swap these parts into a 3.0? Would I be happy with the 3.0 power (+/- 200HP)? I was always very dissappointed with the power of the 2.7(+/- 180 HP).
Should Dennis and I go for the big power and starve or settle for the 3.0 and get on with life? <img src="graemlins/drink.gif" border="0" alt="[cherrsagai]" />
TIA for any advice
Chris Tuck
'75 911s 2.25L
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catuck, check you class rules before doing anything
If its allowed, then the 3.6 transplant is almost the the only reasonable way to go. I have never heard of anyone being sorry that they did it.
The ssi's & sport muffler will be transplantable as well, though they are a bit small, very impressive power levels can be obtained(ask Rich Glickel) w/ the additional use of warmer than stock cams. None of the other 2.7 pieces except possible the throttle linkage are needed on the 3.6. Sell the 2.7 to partially offset the costs.
If its allowed, then the 3.6 transplant is almost the the only reasonable way to go. I have never heard of anyone being sorry that they did it.
The ssi's & sport muffler will be transplantable as well, though they are a bit small, very impressive power levels can be obtained(ask Rich Glickel) w/ the additional use of warmer than stock cams. None of the other 2.7 pieces except possible the throttle linkage are needed on the 3.6. Sell the 2.7 to partially offset the costs.
Instructor
Joined: Jun 2001
Posts: 118
Likes: 1
From: Auckland, New Zealand
This is as good a place as any to ask this.... so away I go.
I ended up shying away from a 3.6 because:
a) I wanted something a little peakier and which looked and sounded like an early engine
b) I was scared of the extra cooling issues with a 3.6 (and the basic requirement to run a front mounted cooler with a new spoiler)
Being in New Zealand didn't help the decision as it is more expensive to get the 3.6 conversion bits over here.
But what I really wonder about is the cooler. How many $$$ does it end up being when you have to buy a new bumper etc as well? Jack has an alternative (to a front mounted cooler) but it took a hell of a lot of work...
Just to clarify, this should really be answered on the basis of no labour cost (ie DIY) and the drive in-drive out labour cost...
I ended up shying away from a 3.6 because:
a) I wanted something a little peakier and which looked and sounded like an early engine
b) I was scared of the extra cooling issues with a 3.6 (and the basic requirement to run a front mounted cooler with a new spoiler)
Being in New Zealand didn't help the decision as it is more expensive to get the 3.6 conversion bits over here.
But what I really wonder about is the cooler. How many $$$ does it end up being when you have to buy a new bumper etc as well? Jack has an alternative (to a front mounted cooler) but it took a hell of a lot of work...
Just to clarify, this should really be answered on the basis of no labour cost (ie DIY) and the drive in-drive out labour cost...
Race Car
Joined: Jun 2001
Posts: 3,929
Likes: 70
From: Los Angeles
It's actually simpler than that, Cam. Since the power steering pump replaced the engine mounted cooler in the C2, and since you don't use the power steering pump in a conversion, you simply put an engine mounted cooler from a Carrera in the space.
The shop where I got my car worked on just did a 3.6 this way, and I've seen it done on other conversions. It's on the 'things I wish I had known when I started out' list.
The extreme cooling measures are only needed for dedicated track work, by the way. This is true for most models of 911's. Adequate cooling on the street is rarely adequate on the track.
The shop where I got my car worked on just did a 3.6 this way, and I've seen it done on other conversions. It's on the 'things I wish I had known when I started out' list.
The extreme cooling measures are only needed for dedicated track work, by the way. This is true for most models of 911's. Adequate cooling on the street is rarely adequate on the track.
Racer
Joined: Jun 2001
Posts: 486
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From: Scottsdale, AZ
In my opinion, if you do go with the 98mm pistons, you should also go with a 930/3.2 carrera 74.4 crankshaft for a displacement increase to 3.4. I bought one a couple of years back for that modification. One of these days I'll do it, but I haven't felt a need yet.
As far as engine conversions, I have a different opinion than most. I have driven plenty of 3.2/3.6 and turbo conversions. The 3.2 and 3.6 conversions feel nice to me but they never leave me white knucked in disbelief like the modified 3.3 turbo conversions (ever 3.3 turbo is modified since it is so easy). Drive any sc/carrera with a modified turbo motor in it and you will see what I mean. Not to mention the hp you get for the money and the fact that the 3.3 turbo has a heater system and throtle linkage designed to be used in a non-964 chassis.
The neatest conversion I saw was in a 2.7 rs lookalike that they fit an intercooled 3.3 liter turbo into and it all fit under the ducktail. Talk about sleeper. Lag has never been an issue for me when I drive turbos. Though it used to be a long time ago when I didn't know the proper way to drive a turbo on a track.
In my car, I will eventually go 3.4 since it is the extra little bit of power that I need to get by the Z06's quicker. I don't want much more power because I dont' want to upset the perfect balance in my car. Bigger this means bigger that, which requires a bigger that to go with the bigger that and etc... I don't need that. And when I do, I will go turbo.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
As far as engine conversions, I have a different opinion than most. I have driven plenty of 3.2/3.6 and turbo conversions. The 3.2 and 3.6 conversions feel nice to me but they never leave me white knucked in disbelief like the modified 3.3 turbo conversions (ever 3.3 turbo is modified since it is so easy). Drive any sc/carrera with a modified turbo motor in it and you will see what I mean. Not to mention the hp you get for the money and the fact that the 3.3 turbo has a heater system and throtle linkage designed to be used in a non-964 chassis.
The neatest conversion I saw was in a 2.7 rs lookalike that they fit an intercooled 3.3 liter turbo into and it all fit under the ducktail. Talk about sleeper. Lag has never been an issue for me when I drive turbos. Though it used to be a long time ago when I didn't know the proper way to drive a turbo on a track.
In my car, I will eventually go 3.4 since it is the extra little bit of power that I need to get by the Z06's quicker. I don't want much more power because I dont' want to upset the perfect balance in my car. Bigger this means bigger that, which requires a bigger that to go with the bigger that and etc... I don't need that. And when I do, I will go turbo.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Instructor
Joined: Jun 2001
Posts: 118
Likes: 1
From: Auckland, New Zealand
Thanks Jack - that is really interesting - I personally would be completely satisfied with an engine and 1 external cooler. From what I have seen, I wouldn't want a single fender mounted cooler in isolation though.
I see your point about the extreme part of what you did being needed only because you give it what-for at the track. But, rather like you, I am anti-RS bumper and would never use a front mount cooler. Hence I shied away from the 3.6.
Yeah, adding an engine cooler to a 3.6 certainly adds another dimension to the whole deal.
I see your point about the extreme part of what you did being needed only because you give it what-for at the track. But, rather like you, I am anti-RS bumper and would never use a front mount cooler. Hence I shied away from the 3.6.
Yeah, adding an engine cooler to a 3.6 certainly adds another dimension to the whole deal.
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RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
[quote]Originally posted by CamB:
<strong>Thanks Jack - that is really interesting - I personally would be completely satisfied with an engine and 1 external cooler. From what I have seen, I wouldn't want a single fender mounted cooler in isolation though.
I see your point about the extreme part of what you did being needed only because you give it what-for at the track. But, rather like you, I am anti-RS bumper and would never use a front mount cooler. Hence I shied away from the 3.6.
Yeah, adding an engine cooler to a 3.6 certainly adds another dimension to the whole deal.</strong><hr></blockquote>
Hi Cam:
Just a couple of items on this subject as we have completed 7 of these conversions now and we have learned a little bit more on each one.
We have used various combination of oil coolers to
control oil temps as this is a big factor for engine durability. To a point, the cooler they run, the longer they last. Most of these have required 2 coolers and for the people like yourself who do not want the RS bumper or a front cooler, we use a pair of C2 oil coolers (one in each fender). The battery boxes are removed so air can flow from the small grilles next to the turn signals, and we've even used the fog light openings to duct air across the coolers. There is no question that each person's environmental's and usage dictates what solutions will be best.
I like having that pressure side oil filter so we have retained that, again in the interests of engine longevity, and the dual front coolers along with a bigger custom lower fan pulley we make, has pretty well done the job, even under track conditions.
I prefer to see oil temps no hotter than 210 deg F under any circumstances. The valves, guides, and P/C's last longer this way.
Hope this is helpful.
<strong>Thanks Jack - that is really interesting - I personally would be completely satisfied with an engine and 1 external cooler. From what I have seen, I wouldn't want a single fender mounted cooler in isolation though.
I see your point about the extreme part of what you did being needed only because you give it what-for at the track. But, rather like you, I am anti-RS bumper and would never use a front mount cooler. Hence I shied away from the 3.6.
Yeah, adding an engine cooler to a 3.6 certainly adds another dimension to the whole deal.</strong><hr></blockquote>
Hi Cam:
Just a couple of items on this subject as we have completed 7 of these conversions now and we have learned a little bit more on each one.
We have used various combination of oil coolers to
control oil temps as this is a big factor for engine durability. To a point, the cooler they run, the longer they last. Most of these have required 2 coolers and for the people like yourself who do not want the RS bumper or a front cooler, we use a pair of C2 oil coolers (one in each fender). The battery boxes are removed so air can flow from the small grilles next to the turn signals, and we've even used the fog light openings to duct air across the coolers. There is no question that each person's environmental's and usage dictates what solutions will be best.
I like having that pressure side oil filter so we have retained that, again in the interests of engine longevity, and the dual front coolers along with a bigger custom lower fan pulley we make, has pretty well done the job, even under track conditions.
I prefer to see oil temps no hotter than 210 deg F under any circumstances. The valves, guides, and P/C's last longer this way.
Hope this is helpful.
Instructor
Joined: Jun 2001
Posts: 118
Likes: 1
From: Auckland, New Zealand
Thanks Steve - it is very helpful as I have a related issue.
I now have about 270hp (245 at wheels) from a 3.2 short stroke and I need to keep an eye on temps. So far it heads up to and sits at 210 with an engine cooler and a fender mounted RX7 cooler.
But the weather hasn't been hot here...
I will start worrying if it gets too much hotter or affects oil pressure I think.
I now have about 270hp (245 at wheels) from a 3.2 short stroke and I need to keep an eye on temps. So far it heads up to and sits at 210 with an engine cooler and a fender mounted RX7 cooler.
But the weather hasn't been hot here...
I will start worrying if it gets too much hotter or affects oil pressure I think.
RL Technical Advisor
Joined: May 2001
Posts: 11,870
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From: Portland Oregon
[quote]Originally posted by lunchbox:
<strong>Nitrous kit: $500
installation: $300
full tank of laughing gas: $40
blowing away everyone on the motherf#cking planet: pricless</strong><hr></blockquote>
Quite true,...but not for long.
<strong>Nitrous kit: $500
installation: $300
full tank of laughing gas: $40
blowing away everyone on the motherf#cking planet: pricless</strong><hr></blockquote>
Quite true,...but not for long.
Advanced
Joined: Apr 2002
Posts: 54
Likes: 0
From: Providence, RI
[quote]As far as engine conversions, I have a different opinion than most. I have driven plenty of 3.2/3.6 and turbo conversions. The 3.2 and 3.6 conversions feel nice to me but they never leave me white knucked in disbelief like the modified 3.3 turbo conversions (ever 3.3 turbo is modified since it is so easy). Drive any sc/carrera with a modified turbo motor in it and you will see what I mean. Not to mention the hp you get for the money and the fact that the 3.3 turbo has a heater system and throtle linkage designed to be used in a non-964 chassis.<hr></blockquote>
Ed has intrigued me! Is this conversion easier or more difficult than the 3.6? More or less expensive? How much power are we talkin about?
I'm interested in as much power for as little money as possible! (who isn't)
Chris Tuck
'75 911soon to be sleeper!!! <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />
Ed has intrigued me! Is this conversion easier or more difficult than the 3.6? More or less expensive? How much power are we talkin about?
I'm interested in as much power for as little money as possible! (who isn't)
Chris Tuck
'75 911soon to be sleeper!!! <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />
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Joined: Jul 2001
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From: Fremont, CA
How much HP can the factory CIS system support? I have an 82 911SC, that is in dire need of a top end due to excessive oil consumption. My thought is to regrind the cam to 964 or Webcam 20/21 (or the Elgin equivalent). Depending on what I find I may re-ring and reuse the pistons & cylinders, get some JE 9.5:1 or look for a good price on a Mahle euro SC piston & cylinder set. If I have to replace the P&C's anyway, 3.2's may make sense. Because I am in California, I cannot change to carbs, and for the forseeable future I am stuck with the so-called 91 octane ****-water they pawn off as Premium gas. I have SSI's, and am willing to swap them out every 2 years for a smog check.
Euro SC's got 204HP with a essentially just compression change. I am thinking 9.5:1, with a cam and SSI's would be a nice little engine. I also read a post by Bill Verburg in another thread about a "83 SC, 98mm Mahle 9.3 CIS top pistons, 964 grind cams going lean mid to top", and the fix was a Carrera 3 FD. I am stuck with the Lamda system, so I don't think the C3 or Euro SC FD is an option.
What is the best you can do with stock CIS parts?
Tom
Euro SC's got 204HP with a essentially just compression change. I am thinking 9.5:1, with a cam and SSI's would be a nice little engine. I also read a post by Bill Verburg in another thread about a "83 SC, 98mm Mahle 9.3 CIS top pistons, 964 grind cams going lean mid to top", and the fix was a Carrera 3 FD. I am stuck with the Lamda system, so I don't think the C3 or Euro SC FD is an option.
What is the best you can do with stock CIS parts?
Tom
Advanced
Joined: Apr 2002
Posts: 54
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From: Providence, RI
Tom,
Follow this link to a Pelican Parts tech artical on getting power out of a CIS injected motor:
<a href="http://www.pelicanparts.com/techarticles/911_engine_rebuild/911_engine_rebuild2.htm" target="_blank">http://www.pelicanparts.com/techarticles/911_engine_rebuild/911_engine_rebuild2.htm</a>
Chris Tuck
'75 911s
Follow this link to a Pelican Parts tech artical on getting power out of a CIS injected motor:
<a href="http://www.pelicanparts.com/techarticles/911_engine_rebuild/911_engine_rebuild2.htm" target="_blank">http://www.pelicanparts.com/techarticles/911_engine_rebuild/911_engine_rebuild2.htm</a>
Chris Tuck
'75 911s