Best from a 2.0L case
 

What is the best build up for a street 2.0L case. High HP, torque, and reliability. Single plug options prefered.

Max. you can go is 2.7 with single plug (RS P/C with 9.5:1 compression) or 2.8 with similar CR. Add S cams or equivalent and late heads. MFI, Webers or EFI. Selective porting.

Details might include ti valve spring retainers, lightweight valves, upgraded head studs, oil pump, blueprinted rebuild specs, balancing, shot peening, electronic ignition and ....... careful assembly with attention to detail. In addition, add chassis dyno time to optimize spark and fuel.

.... or get a 3.6 if you're on a budget. :-)

MHO,
Sherwood

What kind of numbers can one expect from this?

For the 2.7/2.8, my rough guess is 200-230 depending on configuration. Others might have other thoughts.

Anyone?

In the early 80's I built a 2.7 single plug using an aluminum case and the Euro RS 8.5:1 P/C, 2.2 S heads, S cams and 40 IDA webers with 34 mm venturis and an early S distributor.

The case was modified with squirters for the pistons (theoretically required with the Nikasil cylinders) and the late oil bypass plug for the pressure relief. No boat tail or moon cut on the cylinders.

Engine ran very strong with good throttle response and low end was OK in my 2050 pound 914/6.

I think it was Lou Malone at AJ Racing who gave me a dyno sheet of an engine he built that was similar; the dyno run showed 220 HP- more than a mechanically injected 2.7 RS but his was with open exhaust presumably.

BACK UP.

Is this 2 liter case aluminum or magnesium? This is the biggest factor in getting relaible HP from a 2 liter case. If this is a mag case, you would be doing your wallet a disservice by boring the spigots. You'd be lucky to get 50K miles out of a 2 liter mag case that was bored for 90mm pistons. Additionally, you typically don't want to go over ~200 HP on a street driven 2 liter mag case without MEGABUCK machine work. That said, using Nikasil barrels and 86mm JE pistons (these fit stock spigots) at 9.8:1 CR, 70.4mm crank (2.5L) and the right cams, you could make 230+ HP.

If it is aluminum, you can reliably build a 2.8 screamer that puts out 100HP/liter.

BTW, I assume it is aluminum since your name references a '67 911.

230+ HP out of 2.5 liters depends on the "right" cams. However, the cams necessary for this amount of power might take this out of the realm of a streetable engine.

Weren't RS engines built around the mag case?

Sherwood

Seriously, with the value of SWB stuff escalating, don't cut the case for a street car. Get yourself the parts from a 2,4 and have the case modified for better oil pump, squirters, oil bypass mod.

A 2,4 on that case will be virtually indistinguishable from original and can be put back later. You will also need the heads from the later application.

Why not just rebuild the 2,0? People who buy '67 911's dont do it for the wide tires and huge horsepower, they do it because the car is a time warp machine, back to the days of 165 skinny tires, green gauges with chrome ring, and the flexibility of the early engine. If you want to go fast in a straight line, consider a 930. If you want to go fast around corners, put the $$$ into the suspension and keep it flat longer :)

Yes, the RS car cases were magnesium; a 7R mag case, though. A 2 liter mage case means that the case is a 1R case, which had none of the rigidity improvements of the later 7R. They just can't be stressed like a 7R (which also has a larger spigot bore, other than the 73.5 CIS 2.4 case).

As far as getting streetable cams that make that kind of power, trust me, it can be done. John Dougherty (camgrinder) has some wicked profiles that will allow 90HP/L if you are willing to get a little bit exotic with your valve train. The cams I bought from him are expected to make 190 HP on my 2 liter car; oh yeah, the torque curve is significantly fatter than a stock 'S' cam, too! They should be going in sometime in the next month or two.

On another note, I also feel that cutting an early aluminum case is a tragedy.

Hope this clears some things up.

I think if you really want bang for the buck in the power department and reliability and are going to change the case anyway, go for an aluminum 3 liter case and build something bigger than 3 liters.

No substitute for displacement and it is a waste of time to mess with a mag case unless you already have one, and then the 7R is the only one worth hot rodding IMHO.

I agree with cupcar: unless you have some demented interest in hot rodding an early mag case (like I do), the best way to go is to use an SC engine as the basis for your project. Best bang for the buck, by far.

Kenik, OK, I'm very curious. Would you mind sharing the info on this latest project? Sorry, don't mean to hijack the thread, but the bait was too irresistable. Thanks!

Here's what I have to say; if you have any more questons, please PM me:

Here was the intial plan: it was going to be run 81mm Cosworth ultra-lightweight pistons in 81mm Nikasil bores, 10.5:1 CR w/ twin plugs. Unfortunately the pistons I was going to buy were out of spec, so I am going to stick with my stock 2 liter 'S' pistons for now.

I have already ordered the cams and had them delivered to Henry: They are a custom flavor of John Dougherty’s DC44, running on 102 lobe centers. They lift .490 at both valves. They have very fast ramps, so overlap isn’t an issue at low revs. It will need a top notch valve train, but that is in the cards, too. It will eventually run special headers designed by Steve Weiner and built by Headers by George.

Speaking of the crank, I was planning to run Pauter rods and have the crank fully gone through and zero balanced by Ollie’s, but have decided to hold off on the complete rebuild; my bottom end is dry and relatively fresh. As a result, I may actually back the cam timing off by a degree or so (for now), so I can take advantage of the extra overlap. Since I am not doing the balancing work now, I woouldn't be comfortable revving the motor to the moon until I have the lighter rods and crank work done.

It will be topped off by the 2.0S MFI system I have sitting in a box in my garage. In the intial configuration (10.5:1, high revs), I expected it to make somewhere between 90 and 100HP/L at the crank; which both camgrinder and Steve Weiner verified as reasonable expectations. In the intial config, the motor was expected to make rising power to 7800 RPM, then fall off ~5HP by 8000 RPM, meaning 190 - 200 HP. In the slightly detuned trim, I expect between +/- 180 HP with a significantly more robust torque curve than 'S' cams in both configs.

Sound like fun?

Absolutely!

Talk about dementia. Here's a weird one my friend and I built.

Used NOS Mahle 2.5 racing pistons from the 70's in 86.7 mm bore. They had a wierd barrel spigot size of around 94 mm or so but there was plenty of meat on the barrels to cut them to the 2 liter case size.

Used them with bone stock 2.2 S heads, Garretson GE 80 cams, 40 IDA's with 36 mm venturis, Aasco valve springs, Ti retainers, usual windage mods to the case and squirters. Carillo rods.

The compression came out at 9.76:1 after doing a very careful cut around the perimeter of the head for clearance to 0.038" so as not to lose too much volume. Displacement came out at 2337 cc with a 66 mm crank (would be 2494 with 70.4 crank they were designed for)

1.5" headers merging to Burns collectors with around a 28" primary leading to a 24" megaphone if I remember correctly.

Anyway made 101 HP/liter on the dyno- used 35 deg advance!!

So here is the delemia, the car is a '67 the motor a '65. I know squat about porsche, only ridden in one once. I want to keep the car looking stock so a 3.xL transplant is out. So lets say we don't cut the case but make other mods (heads whatnot) what to do? and what kind of numbers will it produce?

a 3.0 can look pretty stock to the untrained eye.
your going to have to spend a pretty good bit of money to surpass factory numbers for the S using a 2.0 block. so your going to end up with more money into this for less HP than a 3.0

you can take easy to come by 3.0 and do a few minor things to it and install carbs for less than your talking about spending in order to get 150hp on that 2.0 case.

nearly anything is possible.
you can get 200 or 230hp on that case of yours... but it could be a motor that is measured in hours instead of years, and could end up costing anywhere from 10 to 20K

I have a 2.0
I love it.
but I don't want 300hp out of it, and know that if I did I would need to change motors.

so if you don't want to spend an arm and leg then shoot for 150hp.
brant

Bump

If you want to buy all new pistons, cylinders, heads, crank, and possibly induction, then you can use the factory published numbers to answer your question.

if you are certain that you do not want to cut the spigots on that case then you can build it as a T/E/S in various displacements of 2.0/2.2/2.4

you will have anywhere from 120hp to 180hp
you can make radical modifications past that for another $5-10K
if you want more power.

the most economical thing to do with that case is to keep it stock at 120hp

If you want more power then the most economical thing to do would be to use a different motor. You already do not have a numbers matching motor for your chassis so it wouldn't really hurt resale.

you can buy a 3.0 motor for 4K-5K, with 190hp and that is about 1/3 of the cost of building something similar out of your block.

the question is somewhat impossible to answer, because you haven't defined how much money you want to spend.
as well as how much hp you want to have.

if you want 10hp more than your stock parts will provide, that may be easily obtainable with a few bits and pieces.

if you want 50 - 100hp over what your stock parts will provide that is going to be very expensive. For that reason, people have tried to give you good advice in their response, that you may want to buy a larger motor and save $

you can build a 911 motor at nearly any HP output you want, but the cost of doing so varies greatly.

The beauty of doing horsepower with displacement is that you can build a relatively low compression engine to meet your horsepower target.

You want compression over 9.5:1 to help the low end with the cams it would take to make some high end horsepower in a 2 liter.

I see you are in Stockton and High Compression and California's 91 octane gas are not a happy marriage unless you twin plug the engine.

as a reference point.
I have a stock compression 2.0S with 9.8:1
I blend 91 octane gas with 105 octane unleaded race fuel at a 50% ratio

makes gas rather pricey, but should keep the motor happy with a computed 98 octane.

just wanted to throw this in for the original poster's benefit.

brant

I use 91 octane in Cali when I drive down with no perceivable issues on my 2.0S. It might be wise to dial back the timing a bit if you live there, but I haven't heard anything definitive on this.

Another bump for a thread I'm closely following. I'm also looking to get the best from my 2.0 case.

My 1968 911L 2.0 engine is completely apart at the shop and now it's decision time. The car is in decent shape, and very stock. I plan on keeping it that way for now, and using it for fun weekends/occasional DE's/historic rallies, etc.

I want to use the original numbers matching 2.0 mag case. I realize that swapping in a 2.4/3.0 may be more economical in the short term, but I only want to do this once.

I can do a stock rebuild at 130hp, or modify the existing engine. I'm seriously thinking of buying Mahle 2.0S P & C's, some head work, rejet my Webers, S cams, and end up with essentially a Euro 1968 "S" at 160hp.

Another option is to get 2.2 S P & C's and bump it up to a 2.2S engine, but I'd like to keep it in the 2.0 class as a solid basis for possible future vintage racing classes ;)

http://forums.pelicanparts.com/uploa...1155550322.jpg


Any thoughts would be greatly appreciated.

Thanks,

"....as a solid basis for possible future vintage racing classes "

I'd think a suitably-built, non-numbers matching engine would be more appropriate for that purpose. Tuck the orig. engine in a corner of your workshop for the time being. Do they have concours judges at the vintage races too? (nope).

MHO,
Sherwood

There is always the issue of layshaft and layshaft bearing wear in a 2.0 alloy case. The layshaft runs directly in the case with no removable insert and good layshafts were hard to find last time I looked for one. I would make sure I had a plan in place to address this issue before I dismantled the engine and for sure would not buy any parts until I had surveyed my crankcase.

So, let's say the case is good and if you don't want to bore the case for larger bore pistons and want to use readily available pistons and cylinders, I would go with a 2.4 bottom end (70.4 mm crank, short rods) with stock 2.4 S pistons at 8.5:1 CR or 2.2 S pistons which will give over 10:1 CR on the 70.4 mm crank.

The latest Mahle pistons I have used are made with Nikasil cylinders (really nice, better than original Biral) for the 2.2 and 2.4 S replacement parts so you should probably install a case squirter set to cool the pistons.

I like to use the early pre-74 oil pump, the one with the small pressure/large scavenge pump along with the oil bypass modification normally used with the later pump. This keeps some oil out of the case which appeals to me. Also I use the late SC venturi oil screen pick up on the suction side of the scavenge pump which I feel also helps lower the level of retained oil in the crankcase. Using the later small bore camshaft oil line fittings restricts flow to the cams and increases oil pressure with the small oil pump. I have used the late pressure bypass springs and the late hex head relief valve screw caps. I have only done this on a racing engine.

If you use 84 mm bore pistons I would go to 2.2 heads rather than use the 2.0 modified for the 84 mm bore which I am told some have done. Besides a more flat combustion chamber that fits the bigger bore, the 2.2 heads have bigger valves...which I like.

I am sure many have other opinions......

Hold on tight! I will have a complete '67S/68S 2.0 top end, including pistons, cylinders, heads, cams, cam towers...the whole shebang for sale very soon. I am swapping the '67S top end out on my '69S for a correct '69S set. This should definitely do the trick for you. I can vouch that it is very, very fun to drive and the leakdown numbers are excellent.

Kenikh,

You have a PM. :)