550 Spyder "4 cam"-like engine build up **NEW UPDA

[TurkTurk]

Hey guys. I am starting a project, building a 550 spyder replica using plans from an original frame and the molds taken from an original car restored in NC. I will be building the engine as well and here is what I'm shooting for:

type 1 1600cc
911 heads, bevel drive DOHC
twin-plug ignition using distributors
twin oil coolers with dry-sump lubrication.
carbs. (probably large DCNFS, or solex 40P11)

First: I have read every thread on both the 911 heads and twin plugs. So after looking through all of this information here are my questions for those who know:

1: In order to bolt 911 heads to the bore spacing of the type1, do I "offset" machine the heads in order to avoid modifying the cam towers? How does this affect the performance, flame travel?

2: I know that the porsche 964 uses a dual-distributor system but obviously for 6 cylinders. Could I modify one of these with 009 dizzy internals, utilizing the componets that link the two distributors together?

I sould say this as well: I am hoping to make between 110-130 HP AT MAX with an operating RPM range of 4-7500 RPM with a redline around 8-8500. This was the HP and op range for the original 4 cam and I'd like to stick close to that. Anybody care to comment on the possiblity of reaching those goals?
Lastly, what do you guys think? I know it is a big undertaking, but it would certaintly be an awesome engine to drive. Let me know your input, suggestions ect.

[miniman82]

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Wouldn't it be a whole lot easier to just simply locate a Porsche engine?
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Build thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=212747

[TurkTurk]

If I had $165,000 to spend on an original 4-cam, not to mention the pocketbook to maintain it, I would. Furthermore, this would certaintly be a challenge and a great deal of fun at that

[Glenn]

Here's a 2110 with CB blow through turbo system and 4 Cam fan shroud and fan.

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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

עַם יִשְׂרָאֵל חַי

[sactojesse]

FYI, Jake Raby posted pictures of an original 4-cammer he's working on in this thread:

http://www.thesamba.com/vw/forum/viewtopic.php?t=266611
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1966 Karmann-Ghia convertible

[TurkTurk]

Any info guys?

[Ohio Tom]

You can order an Aluminum case w/o the head studs drilled or inserted. This will allow you to re-locate any/all of the studs required.

Offset boreing the heads would not be ideal, but proper chamber re-shaping should balance things out. Choose your valve sizes accordingly.

One beauty of the T-1 motor is that it's real easy to modify and change. You'll need to completly block off the lifter oiling gallys, but maintain some kind of "dummy" cam to drive the oil pump.

I thought the old 4 cam motors ran 2, 4 cyl distributors.

[TurkTurk]

Thats a good idea. I think i'm going to use an original magnesium case though. What I'll do is plug the old holes in the cylinder heads and then tap new ones there. Yes, the 4 cams did use two 4 cyl distributors. I've heard this is where alot ofthe issues with tuning those motors comes in. Like I said, the porsche 964 distributor is basically one distributor case to another with a belt drive. I imagine that if I use the components which connec them together but replace everything else with reg. dizzy components I should be on my way.

The original 4 cam used an itermediate shaft in place of where a camshaft would be in a pushrod type1/4 engine in order to drive the cams in the heads. I was thinking about running two shafts with bevel and pinnion gears off the front of the engine. If this sounds like simply two much complexity, the original engines were damn near rube-goldberg. I'd kind of like to maintain some of that using shafts. What would the issues be with setting these shafts up in terms of complexity?

[58 Plastic Tub]

TurkTurk-

Knock yourself out.

Glenn-

Any info on the 4-cam shroud in the replicar at CB? Is that from Dario?

[Glenn]

[Jake Raby]

I have been studying the 4 cam engine for the better part of two decades.. Most recently I spent a week at RennWagen Motor Company working with Bill Doyle while getting critical data and dimensions of the cooling system for the solid models that my cooling system is being based from.

While I was there I took 800 photos and will share those with you when I get back to the shop on Monday.

I can add a ton to this thread and I will as time allows. I am building 4 twin plug engines now and over this summer I did several tests in my lab on plug location, count and their effects on power and efficiency...

[M-Owen]

Hey Turk if you get time look up Russ Fellows in London he has already done an engine like this, His is a little ugly but it runs and is reliable, I get the impresion that his concept could be tidied up and made alot more attractive. It may be easier to start with a type 4 engine I think you will find things line up a lot better. I have been collecting parts for a simular project and would like to share some of my findings. I saw in another post that Jake Raby may be working on a 4CAM fan set-up but I was never able to verify that, Maybe he can.

[M-Owen]

I found this link, It might be a good start

http://www.centralvwaudi.com/protoruss.htm

[Mr. T]

[TurkTurk]

Thanks Jake, I look forward to seeing those pictures. The engine is so hard to come by that detailed photos are almost as rare. Furthermore, your experience with building twin plug motors will certaintly be of use. I PM'd you by the way.

Thanks for the other site suggestions, I have actually researched all those. In regards to starting with a type 1 base or a type 4 base, I'd like to stick to the type 1 simply because I have a base of experience and parts to work from.

So..step one will be to obtain the neccsary parts to begin tinkerin, which I am doing right now. I'll keep you guys up dated. Until then, any additional thoughts, comments? I beleive one of the biggest challenges will be shaft-driving the camshafts.

[TurkTurk]

I've posted below on this subject: I am planning on using 911 2.0L heads coupled with their 84mm pistons and cylinders. With a 69mm crank this will give me a discplacement of 1530cc's which is right were I'd like to be. The issue is that the case I am using (a J code AS21 without the fuel pump) utilizes bores for 85.5mm. My imagined solution to the problem is to simply machine spacers that have an O.D of the case bore and an I.D for the cylinders. Any thoughts?

Furthermore, the bolt spacing (bolt circle) on 911 cylinders is larger than on type 1 cylinders which will require either to plug and re-drill and tap holes in the case(welding magnesium case without warpage??), or I could just enlarge the holes in the 911 cylinders to allow them to fit the type 1 dimension (its only off by a few millimeters over the diameter) Suggestions?

[mightymouse]

IMHO. this is gonna be cool, but the question arises, why spend so much money, for all this one off trick stuff, to only have 130 hp?
my 1679 did this with pump gas. you could have a wonderful 1955, or 2007 that will spin 8500 all day, and make 200 easily on pump. for 1/4 what youll spend on this project.
not to rain on the parade, i like stuff like this. but i just wanted to pose that question. cause its what first popped into my mind.

[M-Owen]

This might get me in trouble.... Maybe you could contact Charles at LN engineering about machining cylinders and pistons to fit your application you would have to spend a little extra but I think it would work alot better than spacers. In order for spacers to be effective they would have to be of a simular metal to either the cylinder ( pressed on) or the case (pressed in) . I also wanted to send you some CAD drawings of the 908 engine this might give you some suggestions about bevel drives. The only other problem I ran into was the cam towers,I have not figured this out yet, but I suspect that you will have a little more to worry about since you are going type 1. I will find the Drawings when I get to my office and send you a note with my Email address.

[TurkTurk]

Definately send me the drawings M-owen, I'd appreciate that. As for why do this, it is really about just having a unique engine in my 550 replica that more closely captures the spirit of an original 4 cam motor in function, feel, ect. I'd only like to make 110-130 HP because thats all these 4 cam's had in the day. Also, I love the challenge. In terms of the money, I am really fortunate to have done alot of work with a full-capability machine shop and I am close friends with alot of the guys that work there so machining costs are negligible. IN addition, I am affiliated with Georgia Tech in Atlanta, GA and I have alot of resources to draw on there. One last thing: the actual cost of good used 2.2L heads, cylinders, ect isn't actually that bad so the actual cost of raw materials isn't crazy. Just wanted to point that out.

In regards to the cylinder spacers: I am fairly certain that I can use aluminium spacers as the coef. of expansion between AS21 and 6061 is small. And, if they are made correctly, the difference of expansion of cast iron on magnesium vs. cast iron on aluminium on magnesium won't be that great. However, can anyone comment on the side loads of cylinders where they enter the block? I imagine that it isn't that great and that properly made spacers there wouldn't be cause for weakness.

I've received emails from several people that have built these engines before and they suggest leaving the 911 bore spacing alone ( some guys, including russ fellows, used to offset grind the heads) so that the heads bolt to the cylinders and the cylinders bolt to the case with the only modification being the bolt spacing on the case. (911 are individual heads per cylinder which makes this possible) You would then modify the cam towers to fit the new spacing ofthe type 1 engine, cut and shorten, ect. I'd don't see this being a huge issue because the component most affected would be the camshaft and I'll be making custom camshafts anyway!

[M-Owen]

I absolutely agree with you, I am doing one simular to Russ' using a type 4 as the starting point, My engine will end up in my 912. I would however like to have an atractive engine when I finish, I am using Porsche 95mm Pistons and Cylinders and 3.2 Heads. My thoughts are to use Custom Rods ( one of my major expenses) This way I can use the stock crank journals and the stock wrist pins . I am stuck on several issues, Camshaft design for one ( I can't visualize the camshafts yet )and I am having trouble deciding on what type of oil system to use Wet or Drysump. I just bought a second set of Cam towers to Cut and have Electron beam welded back together to see if my Camtower idea will work. One other thing I did finish a dual plug distributor that was the easiest task, one of the nissan truck motors has a four cylinder engine with eight plugs if you modify an 009 to fit that cap and rotor your home free with very little expense