touring power, build an engine !!!! Options

[orangecrate]

So I been workin on the orangecrate off an on for what seems like forever... seems I now have rod issues. Knock knock.... Any way I'm lookin at building a motor, or rebuilding. Inexpensively (IMG:style_emoticons/default/lol-2.gif) I have only 2 real conditions I want to meet. 1- It will run 80 mph all day thru the desert in the summer in Phoenix and sit at stoplights with out cooking itself. 2- It will pull the 6% grades that you hit leaving the valley at 70 in the summer without cooking itself. 75 would be nicer. Guess I"m talking a torque motor. This is a stock 72 with stock gearing. And maybe one size up tires. Did I say it needs to be reliable? Like Phoenix to Portland and back any time of year reliable. And inexpensive.. I'd love to buy a Raby motor but $$$. Oh yea. I will be doing the assembly myself. And I'd like to use as much of the 1.7 as possible if possible. Thanks for the input. Build away. (IMG:style_emoticons/default/beer.gif)

[mepstein]

Add an oil cooler. Tangerine makes a bolt on kit.

[Superhawk996]

2.0L Stock or maybe 2056 is probably the sweet spot in my opinion. Combine with external oil cooler as Mark suggests will be your best bet short of moving to water cooling. Your situation in AZ with the temperatures and the long grades is a challenge for a 914 as I'm sure you're aware. As long as you avoid lugging the grades, you will be OK with an external cooler.

2.0L crank is bascially a small stroker over a 1.7L No need to get crazy here if you want durability.

Just in case anyone is not aware of the forumla:
(RPM * T) / 5252=HP

Only two ways to make more HP. Make more torque or spin the engine faster. Or, a combination of both.

Type 4 has a bit of an upper bound w.r.t. spinning them faster. Sure there are people that spin them to 7200 or 8,000 for racing purposes but that comes with durability implications both for the valves (i.e. valve float) and for the crank on the bottom end due to the nature of the T4 crank.

That leaves make more torque. That comes from either a stroker crank or bigger pistons setting aside implcations of getting more air flow into and out of the head to support the increased dispalacments.

You could go to a "bigger stroker" crank but at some point the increased stroke of the crank begins to work aginst you by generating bigger forces on the crank (and bearings) than it was designed to handle.

Bigger pistons also work against you beyond a resonable limit by increasing inertial forces on the crank and by generating more torque on the crank than it was desinged to handle. Larger displacement, bigger pistons (i.e more fuel burned) = more heat. Since cooling is limited by the T4 centrifugal fan, there isn't a whole lot more heat extraction you can get without going to Nickies which is what is at the heart of the Raby Kit both in terms of $$ and ability to make more power without compromising durability much. If you can afford them, I'd do them.

The cheapest, easiest way to get more heat out and away from the engine is via external oil cooler as suggested by Mark. Next would be to consider the Thermal Barrier Coatings inside the head combustion chamber and exhaust ports to keep heat out of the heads and high emissivity coatings on the head exterior to help transfer heat out of the heads. HAM can assist you with either of these coatings on their heads.

Bottom line, the crazier you get from 2056, the more cooling problems you'll generate with limted solutions to keep it durable.

Big six or Porsharu are going to be your best bets to get more way more HP and keep the durability.

[Mark Henry]

First is it knocking? Many newbies mistake a "knocking sound" from the normal sounds an aircooled engine makes, especially at idle. If the "knocking sound" disappears as soon as you apply power and never gets louder then you just may not be used to the sounds an AC engine makes. If it truly is knocking then you should be still able to hear it as you drive and the noise should be getting progressively a lot louder as time goes by.

As far as power and/or a rebuild goes you need give us a budget range, because one man's version of cheap is another's man's damn expensive, just saying "cheap" tells us nothing. For example you say a Raby engine is too expensive, but if you DIY that's almost half the cost, so a $8-10K budget which some may consider "cheap". Flip side of that is you have totally unrealistic budget, a case of beer isn't going to cut it.

Are you using the 1.7 stock Djet FI induction or carbs? What exhaust?
What you have? Just the engine in the car? Do you have any spares? A lot of owners have spare core engines, etc., that we can use towards a project.

You need to give us some more info.

[rhodyguy]

Do the 1.7 case spigots and heads limit cyl/piston selection?

[Bleyseng]

As Superhawk says - a 2056cc with a external oil cooler, Raby 9590 cam & lifters, HAM setup AA 2.0L heads with internal coatings and stock Djet FI or Ljet FI, SSI exchangers and a Triad or Bursch exhaust.
115 to 120HP and runs cooler.

[Superhawk996]

Do the 1.7 case spigots and heads limit cyl/piston selection?

Only to the extent that 1.7L heads have smaller valves/ports and will limit airflow. Machine work can fix case/head fit.

I built my original car's engine from a 1.7L and at the time I couldn't afford 2.0L heads. I went 96mm flat top pistons, carbs, performance cam, and had the 1.7L heads fly cut to accomodate the 96mm cylinders. The engine never really achieved it's potential from the displacment bump due to the heads restricting flow and my running stock heat exchanger pipes (minus exchangers for weight reduction (IMG:style_emoticons/default/lol-2.gif) ). Upping the compression ratio helped. Better than what I had started with but certainly wasn't Raby HP (IMG:style_emoticons/default/smile.gif)

Per Mark Henry's note. Budget really needs to be known. I had sort of assumed that best plan would be to source fresh 2.0L AAP heads from HAM but those alone are $1700-1900 per pair (with aforementioned coatings) so may not exactly be "cheap" depending on OP's point of view.

[orangecrate]

First is it knocking? Many newbies mistake a "knocking sound" from the normal sounds an aircooled engine makes, especially at idle. If the "knocking sound" disappears as soon as you apply power and never gets louder then you just may not be used to the sounds an AC engine makes. If it truly is knocking then you should be still able to hear it as you drive and the noise should be getting progressively a lot louder as time goes by.

As far as power and/or a rebuild goes you need give us a budget range, because one man's version of cheap is another's man's damn expensive, just saying "cheap" tells us nothing. For example you say a Raby engine is too expensive, but if you DIY that's almost half the cost, so a $8-10K budget which some may consider "cheap". Flip side of that is you have totally unrealistic budget, a case of beer isn't going to cut it.

Are you using the 1.7 stock Djet FI induction or carbs? What exhaust?
What you have? Just the engine in the car? Do you have any spares? A lot of owners have spare core engines, etc., that we can use towards a project.

You need to give us some more info.

I put a few miles on this before it went down for a lot of work , none engine related. It sat for some time (yrs) with out running. When I finally got it roadworthy and awakened it from it's slumber, that damn green light stayed on way too long after it lit off. My kid, a certified ,factory trained Porsche tech, who has gone to the dark side and is now a factory trained Ferrari tech, heard that nasty little noise too. We agreed it sounds like a rod knock. I would like to stay with FI but I understand the DJet really isn't very compatible with anything but factory stock. Plus it is Stock, meaning everything is pushing 50 yrs old Probably run the stock exhaust so I can have heat if I go north. Haven't ran it in AZ so not sure how it would pull the grades here. I know they are deceiving. once you leave the valley, you are going up north and east.
I said inexpensive , not cheap. I'll buy quality stuff if I need too, but only what I need. This isn't a hot rod, as much as I'd like to go the whole outlaw route. If that were the case , I'd go looking for an aluminum V6. But that's another ball game. All I have is the engine in it . If I can meet my goals staying close to that ,I'd be happy as a clam. And half the cost of a Raby motor is "inexpensive". Not to knock him in any way, but part of what you are paying for is "Raby". That's just business.

[orangecrate]

Do the 1.7 case spigots and heads limit cyl/piston selection?

Only to the extent that 1.7L heads have smaller valves/ports and will limit airflow. Machine work can fix case/head fit.

I built my original car's engine from a 1.7L and at the time I couldn't afford 2.0L heads. I went 96mm flat top pistons, carbs, performance cam, and had the 1.7L heads fly cut to accomodate the 96mm cylinders. The engine never really achieved it's potential from the displacment bump due to the heads restricting flow and my running stock heat exchanger pipes (minus exchangers for weight reduction (IMG:style_emoticons/default/lol-2.gif) ). Upping the compression ratio helped. Better than what I had started with but certainly wasn't Raby HP (IMG:style_emoticons/default/smile.gif)

Per Mark Henry's note. Budget really needs to be known. I had sort of assumed that best plan would be to source fresh 2.0L AAP heads from HAM but those alone are $1700-1900 per pair (with aforementioned coatings) so may not exactly be "cheap" depending on OP's point of view

[orangecrate]

[quote name='orangecrate' date='Dec 7 2019, 01:51 PM' post='2768053']
[quote name='Superhawk996' post='2768030' date='Dec 7 2019, 12:56 PM']
[quote name='rhodyguy' post='2768007' date='Dec 7 2019, 02:58 PM']
Do the 1.7 case spigots and heads limit cyl/piston selection?
[/quote]

Only to the extent that 1.7L heads have smaller valves/ports and will limit airflow. Machine work can fix case/head fit.

I built my original car's engine from a 1.7L and at the time I couldn't afford 2.0L heads. I went 96mm flat top pistons, carbs, performance cam, and had the 1.7L heads fly cut to accomodate the 96mm cylinders. The engine never really achieved it's potential from the displacment bump due to the heads restricting flow and my running stock heat exchanger pipes (minus exchangers for weight reduction (IMG:style_emoticons/default/lol-2.gif) ). Upping the compression ratio helped. Better than what I had started with but certainly wasn't Raby HP (IMG:style_emoticons/default/smile.gif)

Per Mark Henry's note. Budget really needs to be known. I had sort of assumed that best plan would be to source fresh 2.0L AAP heads from HAM but those alone are $1700-1900 per pair (with aforementioned coatings) so may not exactly be "cheap" depending on OP's point of view

[orangecrate]

There is a very good Porsche wrecking yard in PHX. I'm not against good used parts either. I'm not familiar with all displacement increases with new pistons, What does the 96mm give you? and where in the rpm range did your motor run out of steam due to the small heads?

[orangecrate]

As Superhawk says - a 2056cc with a external oil cooler, Raby 9590 cam & lifters, HAM setup AA 2.0L heads with internal coatings and stock Djet FI or Ljet FI, SSI exchangers and a Triad or Bursch exhaust.
115 to 120HP and runs cooler.

What are we talking $$$ wise here?

[Mark Henry]

As Superhawk says - a 2056cc with a external oil cooler, Raby 9590 cam & lifters, HAM setup AA 2.0L heads with internal coatings and stock Djet FI or Ljet FI, SSI exchangers and a Triad or Bursch exhaust.
115 to 120HP and runs cooler.

What are we talking $$$ wise here?

Starting from almost scratch I'd say that parts list is easily over $5K.

[Superhawk996]

There is a very good Porsche wrecking yard in PHX. I'm not against good used parts either. I'm not familiar with all displacement increases with new pistons, What does the 96mm give you? and where in the rpm range did your motor run out of steam due to the small heads?

96mm pistons with the 2.0L crank stroke of 71mm is a 2056 cc engine.

[Superhawk996]

There is a very good Porsche wrecking yard in PHX. I'm not against good used parts either. I'm not familiar with all displacement increases with new pistons, What does the 96mm give you? and where in the rpm range did your motor run out of steam due to the small heads?

My rebuilt 1.7L 66m crank with 96mm pistons = 1910cc. I had Weber 40 IDF carbs, a Bosch 009 distributor (dont' get me started - it was the late 80's I was young and stupid (IMG:style_emoticons/default/rolleyes.gif) ) and a performance "carb" cam (for which I don't remember the exact spec's) had a decent powerband from 2500 rpm - about 4500 rpm but then it seemed to run out of steam on it's way to 5500 rpm. Basically just making noise, building RPM's a bit slower, and not really "pulling" like it did in the power band.

I wish I had known more back then. I wouldn't do that engine again. (IMG:style_emoticons/default/happy11.gif)

[thelogo]

Building a expensive .aircooled .motor that need to be reliable .

Your way outta your league ....
Go build a dozen stock 1600cc that run and then maybe youll be ready for the big/4

But your heading for dissapointment.

Subaru motor is what you need ....
Cheap modern and much more diy friendly .

Relaible ? Jurys out on that one .

But try to spend the money not waste it

[Tdskip]

My rebuilt 1.7L 66m crank with 96mm pistons = 1910cc. I had Weber 40 IDF carbs, a Bosch 009 distributor (dont' get me started - it was the late 80's I was young and stupid (IMG:style_emoticons/default/rolleyes.gif) ) and a performance "carb" cam (for which I don't remember the exact spec's) had a decent powerband from 2500 rpm - about 4500 rpm but then it seemed to run out of steam on it's way to 5500 rpm. Basically just making noise, building RPM's a bit slower, and not really "pulling" like it did in the power band.

I wish I had known more back then. I wouldn't do that engine again. (IMG:style_emoticons/default/happy11.gif)

@Superhawk996 - just a 2.0L or 2056 instead?

[Superhawk996]

showuser=22428]Superhawk996[/url][/b] - just a 2.0L of 2056 instead?

@Tdskip

I'd be hesitant to call it a 2.0L (IMG:style_emoticons/default/dry.gif) It was really 1.9L of displacement trying to suck air though the smaller 1.7L valves and didn't have the benefit of reoriented spark plugs either.

It was the best I could manage when I was just out of the military and working on my 1st year of college. I wouldn't even have rebuilt it but the dreaded oil lamp flicker at idle suddenly happened one day and and it sort of turned into a "while it's apart" excercise but on a shoestring budget.

As metioned, it was a great learning experience but I wound't recommend it. (IMG:style_emoticons/default/rolleyes.gif) Better than a stock 1.7L but it was probably just barely making 2.0L stock power if even that much. It went a boat load of miles though and was very reliable after the rebuild.

[Tdskip]

@Superhawk996 - thanks for the response but I wasn’t very clear. Is your take away not to build from a 1.7 and start from a 2.0L case and crank instead? Make sure to use modified 1.8 or 2.9L heads?

[orangecrate]

Been doin a little figuring and thinking . Based on some very rough estimates and the reliable (ha) butt dyno, I figure I need at least 100 hp to reach my goal. What I really need is torque, as we're talkin hillclimbing here. 70 mph up a 6% grade for 6 miles in the summer in AZ. That's just keepin up with traffic on I 17 North outta Phoenix. Is that possible with a well built (balanced piston, rods, flywheel) 1.7? Or am I overly optimistic. Or just ignorant?? (IMG:style_emoticons/default/biggrin.gif) How many of you have pulled that sort of grade in our little cars??