performance upgrades

If you don't want to pull apart the bottom end, you're limited to 1641ccs (boring out your existing 85.5s to 87mm). Those p/c kits are downright cheap. I would at the bare minimum, if doing a top end rebuild, send out the heads to be rebuilt at Rimco. I don't really see this route costing more than $500. If you were to tear into the bottom end, you could have the case bored out for 90.5s (1776) or 94s (1915). I don't recommend doing the 92s, due to their thin walls. New bearings, head studs (chromoly), cam, and lifters, along with the machining required, would bring you to your ~$1300 budget.

Charles Navarro
LN Engineering
www.LNengineering.com
Aircooled Precision Performance

Since winter is just around the corner I am thinking of doing some performane upgrades on my 1600cc dual port weber 40IDF and get it ready for next season.A friend of mine told me that I can keep the same engine and bore out the cylinders to 92mm (1835cc).If I do that how much hp will I be able to gain.What I want to see at the end is 100hp or more if it is possible.The bottom line is that I have 1300 bucks to spent in parts and labor.Please give me an advice on how to increase the hp with the budget that I have.Thanks

Charles--Installing 87mm p/c do NOT require any machining (heads or case) They are a direct slip-in fit. Anything larger (90.5-94mm) require machining

Save your money, $1,300 probably isn't going to get you to 100 BHP.

Build a 1914 x 69 with a counterweight crank w/ 8 dowel pins, Eagle 110 cam, full flow the case, weld and set #3, add case savers, decent mid range ported heads, solid rocker arm shafts w/ high rev springs, mild carbs, 009 with Pertronix II ignition, 11 lb flywheel, external oil cooler, remote filter...your good to go in the neighborhood of 95 HP. I built and ran a 1914 as described and it ran flawlessly for four years of hard driving and got a constant 34 mpg!

Don't piss around trying to get a few more ponies out of a 1600 or 1650 (something) or even a 1776. Drive your car for a few years, save your money and then get a quality built 1914 or 2110.
Ron

I found this engine for a good price
Displacement 1835cc
Bore size 92mm
Stroke length 69mm
Valve sizes i/e 39mm 32mm
Cam type 110
Camshaft lift i/e 0.392"
Cam duration i/e 284 degrees
Cam duration @.50 lift 247 degrees
Warranty-1 year-12000 miles
I do not know the hp.What do you think?I know I should save my money for a really good one but next season I would like to drive my car out of state and I don't think my 1600 is comfortable on the hihgway.I could invest a little bit more money but I would like to buy my wide fives with new tires,my moto lita steering wheel,lower the rear end, get new shocks,and buy the original looking VDO. Anyway I found that engine at www.rebuilt-vw-engines.com Thanks again

Lambros:

I drove my 1600 c.c. Karmann Ghia cabriolet from Ontario to the East Coast and back when I was younger. Single carb, stock muffler, etc. and cruised along the freeways with no problem. Not an incident on the entire trip - around 2500 miles, I guess.

What do I think? I think everybody tells me to stay away from 92 mm bores. See if you can get the same engine with 94's- it'll be a 1914 then.

ok....dumb question time.........does anyone have a site we can look at that gives us the differences in the Bore and how they come about the larger bore. I'm confused why a 94 would be better??? Wouldn't that leave you with less cylinder then the 92? I must be missing something, but I'm so unknowledgeable on this subject I'm not sure what I missed.

Steve, I believe this is correct.....The 92's are a bored out smaller cylinder, since it's been bored out from the original... it has very thin walls, and therefore prone to overheat. The 94's however are a different and larger casting, and with a bore of 94 still has a lot of meat left to dissapate heat.....if you overbored that casting too far you would end up with the same overheating problem.

Gclarke "The vacaville Guy"

Interesting discussing the 92mm and 94mm engines.
As I mentioned above, I built and ran a 1914 (94mmx69)and (favorite motor)for a few years and ran it hard with no problems what so ever.
"Rocky" (he posts here on occassion) has a 1835 (92mmx69) in his speedster, he runs the car nine to ten months out of the year.
I built the motor at least eight years ago, and it sill runs great.
Engine overheating is the main concern...external oil cooler( added oil capacity) close sealing engine tin, engine compartment sealed properly, timing and carbs that are set up correctly result in a strong, reliable aircooled engine.

Hey gang,

How much extra cost is involved in going up to a 94 vs the 92. It seems to me a no brainer to use the 94's if your going to go big bore.

It rimes get it!!!

The 94mm cylinder and piston set are around $325 - $375 as I posted earlier, this is a strong engine size that is reliable for the long term.

Steve O'Brien,

Check the Knowledge bas one this website. It has a Bore and stroke to displacement matrix.

Another point VW and Porche air cooled engine cases are sleeved. The pistons reciprocate in a steel sleeve that slides into the "case". The sleeve for a 92 is very thin and doesn't efficiently dispurse or conduct heat to the case. In the 92's the thin sleeves get a lot hotter, causing a lot of problems, oil breaks dwon and the case goes granular, or cracks where the sleave meets it, because of the high temperature.

In the 94's the case is bored a bit so that the the sleeve can be a bit thicker, the thicker case makes for better dissapation and conduction of the heat away from the piston and to the case to the cooling fins etc.

I think this is correct. Maybe George Brown or Jake Raby can make it autoritative by adding a bit.

Here in Southern California, 94mm Piston/cylinder made by Mahle in either "a" or "b" stroke range in prices from $180-$210. They are the balanced and forged variety of course.
Then again, you can order a set from Gener Berg. They also carry Mahles, but they get the POTL (pick of the litter) so you'll get the very best. This of course will cost you ($400+)

Glenn,

I realize that the 87s are slips ins, I was referring to the fact that the original cylinders are better bored out and reused than the cheap brazilian crap floating around today, and just purchase the pistons w/o cylinders.

Charles Navarro
LN Engineering
www.LNengineering.com
Aircooled Precision Performance

I'll add another comment on the whole 92 vs 94. I personally prefer the 94s, since they have thicker walls, but... one concern those 92 users have is that there is too much material removed from the case spigot opening around the head studs if you run the 94s. Personally, I don't buy the claim. It also amazes me that aircraft guys run 92s and claim it's more reliable than 94s because of this point. If you tear it down, just put in 94s and be over with it. :-)

Charles Navarro
LN Engineering
www.LNengineering.com
Aircooled Precision Performance

Of course most of the aircraft engines have constant fresh airflow. Thats why I did the cooling upgrades to my car. I'm convinced it is all about getting as much fresh air flow as possible and having as little restriction of exhaust as possible. Of course you will never be able to get as good of air as the airplane does so I think the 94's are a better deal for our cars.

Charles; I thought Mahle were German made. Are they not? Thanks!

Interesting you should mention airplanes. Back in the 80's there was an experimental aircraft called the "Dragonfly" that was a futuristic looking canard winged design using modified VW power. The engine of choice, if I remember correctly, had 1835cc displacement. According to the chart, this would indicate that it used 92's rather than 94's. Since this aircraft typically use a much higher percentage of available power on a continuous basis (about 55% minimum at economy cruise for this example) I assumed that this configuration must be pretty reliable. Losing an engine can be catastrophic in flight, much worse than having to pull over to the side of the road.

I don't know what has happened to Rex Taylor or his aircraft design in recent years as I have lost touch with EAA activities. I hope Rex is still alive and well and has not met the same fate as some other experimental aircraft designers. Chris Beachner and Steve Wittman come to mind.

Robert, after putting 115,000 miles on a near stock 1600 (one valve job) I agree with you....near stock motors go and go and go. While my performance 2110 went fast, there always seemed to be something to fix.
Stock, or near stock motors seem to last for ever, while high performance motors seem to be looking for a place to blow-up.
Ron

Could it be that higher-performance motors always seem to have a heavier foot coaxing them along?

It could that over bored engines using stock crank shaft and bearings to push larger pistons with more contact area on the cylinder walls have more resistance then they where original designed for.

What type of failures are people experiencing in there over bored engines, are they spun bearings?

Cima/mahles are made in brazil now, along with most of the other crap lots of parts dealers are dishing out. There are AA p/c, made in China, along with some other manufacturers that source out again to brazil, but don't even label their brand on the box. Just to give you an idea of the quality of these foreign cast things, in making Nickies in a stock 1600 size, I purchased a set of cima/mahles for reference. The bore was tapered, the registeres were +/- .005", and the bore was egg shaped .0035". Not exactly what I call quality.

And as far as the guys running vw engines in aircraft, just because everyone uses 1835s and claim they have no problems, that just isn't the case. I have never seen more people that run cobbled together, unsafe engines as I have seen with experimental aircrafts. In general, they run hot, have high oil temps, and have exaggerated TBOs that are unrealistic with the excessively high LOW rpm loads placed on the engines. Top that with 90% of them running poorly thought out fuel systems, and it's no wonder they have problems. But most of these guys are lucky if they even put on 150 hours on an engine in the entire life (or their ownership) of the aircraft, so that's in essence why you never hear of problems.

Charles Navarro
LN Engineering
www.LNengineering.com
Aircooled Precision Peformance

Just a guess here.... they plug the idle jet circuit on their IDFs, and they overheat the oil and heads.

It's my opinion (as yet untested, but soon- very soon), that the main relaibility problems with larger, higher performance Type 1 engines are related to heat and carburators. EVERYBODY uses IDFs (except Paul, who is a wild man with IDAs), which are tempermental and difficult for most shade tree guys to jet properly. George can dial 'em in, most guys will spend a month of sundays chasing down the elusive vacuum leak, or plugged jet, and learn to hate their car for it. The other issue is heat. A larger bore (and to a lesser degree, stroke) will add mre heat to the engine. I'm told a 94 mm bore is better than a 92 mm, but I'm sticking with a 90.5 mm because by the nature of our cars, we have an airflow issue. We all know it- George and Steven cut holes in the fire wall. Henry at IM cuts a hole behind the licence plate. John at JPS puts the engine lid on buttons (no seals).

I'm having a 2110 (90.5 bore) built around a set of AJ Sim's modified Kadron carb kits and heads. I'm getting his 46 mm throttle bodies, with 36 mm venturies, welded and ported manifolds, and a set of ported 041 heads. Everything else is being build around this combination. It's gonna' cost as much as a set of CB's 44 IDFs, so there is no cost savings- I'm doing it because I like the idea of a plenumn based carburator better than individual runners, for the tunability/ reliability issue and because of the KIND of power I'm looking for. I'm looking for max h/p in the 150 range at 5500 rpm or so, and (more importantly to me) max torque in the 150 lb/ft range at 3000 (!) rpm. I want torque, and am willing to give up a bit of power on top, to get more torque- sooner- down low. I want a better engine that is as reliable as a hammer, and strong as an Ox.

Will it work? I hope so. I beleive it will, but am not making any (ALL 10s!!!) claims before even I have the engine built. I'm just a guy who likes to work on the car- please don't tke me for an expert, because I'm not- but I do like to think about something before I do it. The cooling system will be critical, and I'm still debating which way I want to go. I'll let you know...

Stan are you considering a Porsche style fan shroud. I think the extra air and the way it looks would be worth it!!!! Does anyone know any drawbacks to this?

Charles, I hope I didn't mislead you by mentioning 1835cc engines in Dragonflys. While the original prototype was powered with a 1600cc engine, the 1835cc (HAPI) became the recommended engine. Dragonflys flying now use these, as well as 2180cc engines, Subaru EA-81's, Continental O-200's and a smattering of others. Even Corvair engine conversions are in the works. Regardless of which engine is chosen, the reliability and safety of the airplanes are directly related to the skill and knowledge of the builder. Once again, you get what you pay for.

Most of the experimental aircraft builders I have met or read about take their engines and engine installations seriously, as well they should when they leave the airstrip. As a result, in 17 years there has been only engine failure which resulted in a fatality. You are quite correct about "cobbled together fuel systems" since this failure resulted from a clogged fuel filter.

Steven, I had a Porsche style shroud on my 84IM, and if I had it all over to do again I wouldn't go this route. Jake Raby's DTM shroud is a much better solution, and from what I've read it cools better (and has a more equal air distribution to all cylinders). The 911 style shroud does look nice, though.

Just for another resource go to CB Performance. Pat has a neat gearing spread sheet set up, all the bore x stroke combos, and a good tech area.

$1500? You might save a little more and then buy a quality long block from a reputable builder in the size you want. Then do your carbs, clutch and ignition, etc on a piece by piece basis. In the long run you will be happier getting it right the first time... at least for a couple of years. Then you'll want more.

For a strong 1776 I would look at Eddie J's build from Strictly Foriegn. A 2110 is also a great engine... look at Pat Down's long blocks and turnkeys to see what internals he is using. I think he has several variations going on the web site; starting with a 1914. He costs a little more, but I understand it's worth it.

From my limited knowledge, it is all in quality parts put together in a combination that achieves a balance. I think that is easier said than done on a home build, unless you know your Type 1s.

Most Porsche 911 fan & shroud setups overcool a VW engine, and depending on the crank pulley to fan pulley ratio take a lot of BHP to spin.

Many high output VW street engines (2,276, 2,332 or 2,387cc) use a late style doghouse shroud and type 3 oil cooler which is usually enough with the flaps and thermostat installed. This stock setup uses the VW type 3 oil cooler mounted vertically; Gene Berg has a kit to enlarge the doghouse and use a type 4 oil cooler (two more rows).

The type 3 cooler used with a thermostatically controlled auxilliary cooler should handle a high output 2,387 engine in hot summer weather, keeping oil temps below 220 F.

And of course there is the 356/912 alternator pulley that can be used to speed up the fan at lower RPM.

That makes sense I never even thought about how much hp it would take to turn it, I was just thinking about the looks mainly, and that is not a good criteria when it comes to things mechanical.

I'm with George on this; a properly build and tuned engine with a modified doghouse and type 4 oil cooler is preferrable over the 911 shroud. A DTM would be superior in every respect to the 911 setup, if additional/balanced cooling is desired.

Charles Navarro
LN Engineering
www.LNengineering.com
Aircooled Precision Performance

Stan:

I have pretty much the same engine you're building; 2,110 with 90.5's and an 82mm crank, 35.5/40 valve ported and polished heads, 294 duration by 435 lift cam, lightened flywheel and all that good stuff.

I went with the stock, German, 1971 fan shroud and cooler, complete with ALL the associated German cooling tins (oops, I have chromed head tins, but the rest is stock), thermostat, air vanes and so forth. Everything is working as the Germans intended it.

All that would keep it cool most of the time, but on hotter days (anything over 80F) the oil temp would begin to creep toward 220F. It never quite got that far, but it was at least 215F, so I added my full-flow oil cooler/filter system (a DeRale 16-pass cooler and thermostat set for 185F). Now, it'll sit around 180 until the ambient temp gets over 75F and then the external cooler kicks in to hold it right at 200F. If I'm hammering it on a turnpike and have to stop for traffic, it'll run up to 205 F and sit there til I start moving again, and then it rapidly goes back to 200F (I have a dipstick thermometer). I now have a 356 fan pulley and haven't noticed any big difference (since it is probably masked by the cooler) but I'm sure that the heads must be a bit cooler with 11% more air flow across them, even if the oil temp is masked.

So the moral of the story for you is; if you're running a 2,110 and want to run these kinds of temps, this is a good, reasonably priced alternative. I have no experience with "Down the middle" or "911" style coolers, having always used a stock German cooling system appropriate for the engine size I was working with. I HAVE, though, worked with enough German designers in the past thrity years to understand that they have probably thought out the type 1 cooling process a whole lot better than I ever would, and I trust them.

Hope this helps......gn

My wife has this peeked expression on her face as she sees me spending hours in front of the computer. I am sure her co-workers tell her he is "really looking at porn" Well it is eye candy but of a different sort.
Gordon,I love the creativity in mounting your dog house externally HOWEVER since it only recieves cooling from ambient air in an enclosed engine bay, how could this be superior to the normal position where the DG is getting blasted from cold air from under the car---or is this a second dg?

Huh?

Yeah, took me a couple of re-reads and then I looked at the picture above again.

OK, that's NOT a cooler on the right, middle of the picture, it is a breather box for the crankcase. It is also where you put the oil in when you add/change the oil. It also has breather lines going to the crankcase and both carbs to cycle oil fumes from the crankcase into the carbs to get burnt off.

I am running a stock, German, VW "doghouse" oil cooler which sits in a spot behind the fan housing just to the left of center, but it's out of sight in that picture, buried behind the fan houseing.

I also have an external, add-on oil cooler tucked into the left rear wheel well, with a 12V fan pulling air through it whenever the oil temp gets over 185F degrees. tHAT cooler holds everything to 200 - 205F max.

gn

Got you with that question, didn't he, Stan?

Yeah, took me a couple of re-reads and then I looked at the picture above again.

OK, that's NOT a cooler on the right, middle of the picture, it is a breather box for the crankcase. It is also where you put the oil in when you add/change the oil. It also has breather lines going to the crankcase and both carbs to cycle oil fumes from the crankcase into the carbs to get burnt off.

I am running a stock, German, VW "doghouse" oil cooler which sits in a spot behind the fan housing just to the left of center, but it's out of sight in that picture, buried behind the fan houseing.

I also have an external, add-on oil cooler tucked into the left rear wheel well, with a 12V fan pulling air through it whenever the oil temp gets over 185F degrees. tHAT cooler holds everything to 200 - 205F max.

gn

Got you with that question, didn't he, Stan?