2450 (78mm x 100mm) engine build

[Type 4 Unleashed]

I, agree with Clatter on using something other than the CB VW650 springs, but not for the same reasons. This is to give you an idea of what to look for. Now, the 650 springs are designed for cams with valve lift from .600" to .630" and the 86b is only .500" lift, The 650 springs @ installed height are @ 160 psi, which is way to much pressure for the weight of such small valves, which actually robs power from the motor, but the over the nose pressure @ 500" lift wouldn't be to bad, basically the springs are not for that cam.

So what you should look for are springs designed for a .500" lift cam, Web has dbl spring good for a cam to .510 lift as an example, but there are others more reasonably priced CB has 1490 singles @ 1.500" are 120 lbs and @ .500'' their 220 pds but no coil bind specs, and the 1491 duals don't show any specs at all, and that's one thing that has always sucked about CB, they give very few specs about their products, and if you call them to inquire, they don't even know. I had called one time trying to find coil bind on a set of their springs I wanted to purchase, they had no idea.

So do your research before you buy anything else.

[Eddie010]

Ray,
Thanks for the info on the spring... needed that.

Richard,
I thought I had gathered enough info, but seems I overlooked some stuff. (especially the max lift for the springs).
But thanks fot the help, now 2 persons said I have to rethink the springs, so will look into this.

This is great help... thank you guys.

[Eddie010]

Clatter,

Weighted the adjusters.

Original M10 adjuster:


SwifelFeet adjuster M10


Ok a bit surprised they weigh the same.
Oooh weight is in grams.

[Eddie010]

http://vwparts.aircooled.net/Beehives-D ... eet-ki.htm

Is this an option, I like that they are single and I don t have to cut the valve guide bosses.
Aircooled net, has printed the specs also… they are for lift up to .550.

Edit: the only thing I don t like about it is the use off keepers, I will have to shim the rockers than.
With probably interference with the stock valve cover.

Ps always had good results with ordering at aircooled.net

[Type 4 Unleashed]

You may not have to shim the rockers very much at all if you go with that setup. The additional installed height looks like it's in the retainer, and the lash caps and swivel feet adj's help clear the retainers. I had a set of Gene Berg retainers the same way, that I was able to set up @ about 1.850" with stock length valves. Rocker geo becomes more involved when you use valves over stock length.

But, you still might have to trim valve boss's some, I believe the Type lV boss's are larger than Type 1 boss's.

[Clatter]

Correct; you do have to cut down the guide boss to the smaller type 1 size to run the beehives..

[Eddie010]

Ok,

Fall/winter is coming so I am starting with machining parts for this engine.
But a question, what would you guys suggest for the sizes to machine the heads and case for the 100 mm cilinders?

I can machine the deutz cilinder in whatever size I want so.
Case is now still standard 100mm
Heads still standard 105mm

I have found some info on cilinder sizes and case and heads sizes
Type 4 Empi 100mm - case 106mm - heads 108mm
Type 4 LN Nickies 100mm - case 108.5 - heads 115mm
Type 4 AA 103mm - case 109mm - heads 115mm
Type 4 Mahle 103mm - case 106.8 - heads 112mm

So what are you guys think also considering good sealing for the heads with the 100mm pistons/cilinder.

Thanks in regards

[Eddie010]

Got some info gathered.
But would appreciate some info from you guys?

[wreck]

Hi Eddie , I would go to the smallest spigot sizes you can , I went to the same size as the AA's and you don't have much left in the case or the heads . I was discussing his with friends a few weeks ago and we all agreed that machining out into the head stud holes on the heads must really weaken them .

[Eddie010]

Collecting some last parts.

[Tony Z]

coming back to your valve spring choice. I run the 86C cam with 1.4 rockers in my T1. Titanium retainers and aly pushrods. I also use the cheap CB dual springs (S40 for the set). My rev limiter is set to 7000rpm and I do not suffer from any valve bounce.
You are using a milder cam and lower ratio rockers. You dont need CB 650's


On my T4 build, I was going to run Deutz barrels before I got QSC nickies practically for free. I also thought about different sizes for the heads, so that I could keep as much strength in the heads as possible. My thoughts? Standard head is 105mm for a 94mm bore. This is a 5.5mm wall and its damn thick. Keith black 96mm uses the same head size, so its 4.5mm thick. The new 92mm thick walls for the T1 are all the rage and they are 4.5mm thick. Stock T1 is 4.15mm thick.
That said, I'd be happy with 4.5mm thick walls using the (super strong) Deutz castings... 100+(4.5x2) = 109mm head size. This will definitely leave your head stronger than it would be with a 112 or 115mm hole

[Clatter]

FWIW, I haven't any experience with big big cylinders,
But, within reason, you're going to want to save as much aluminum meat as is practical.
The cylinders, while a lot of work, are generally cheaper than heads.
Especially the heads; head/cylinder leakage is a known issue with big bores, partly because of the missing strength from cutting the head.
A lot of those type 1 thin-wall 88s aren't known for breaking at the bottom cylinder spigot..

WRT valve springs again..
Here's how much you will have to trim the guide bosses for the beehives - same as for type 1 single springs.


Here's where I weighed a set of those beehives:
https://www.thesamba.com/vw/forum/viewt ... start=1760

Seems that you -might- be able to run without the lash cap if you use the real Porsche swivel feet?
(Still need to mock that up and see)

Did me a bunch of research, talked to John Connelly and Dan Ruddock and on and on..
The 86b on 1.3s is right at the limit lift-wise for the beehives.
in terms of controlling the valves, having 8mm stems, only 42 x 36, 8mm adjusters, and stock type 4 lifters,
I was convinced it would even be safe to run steel pushrods.
If you have even lighter parts... Sounds like you're safer.
(Disclaimer - I'm still just going by what people say, and it will be years before my project hits the dyno and I know for sure).

I went ahead and bought the type-4-specific duals that Web sells and recommends for the 86b,
And they are indeed a set of larger-diameter type 4 springs, not just some re-packaged Type 1 Scats or something.
So there's a reason they cost 4x as much..
They are still sitting here in the wrapper, for an 86c/86b project that's next,
So take me FWIW, or not..

[Eddie010]

Thank you guys.
Good information.
Will help for sure.

[bushoarder]

Eddie
WhAt spec do you have to get 125hp?


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[Eddie010]

Eddie
WhAt spec do you have to get 125hp?


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CJ case with Bus 71 mm crank (CJ case so I could fit a CSP upright conversion)
Bus 2.0 rods with 22 mm bushes for type 1 94mm B mahle pistons.
Crank with 200mm AA Type 4 flywheel, stage two clutch, balanced together.
Schleicher 316 cam with solid lifters.
Aluminium pushrods.
26mm Type 1 oil pump.
CU (square exhaust port) heads with 42x36mm (8mm stem) SS valves
lightly ported. 9.5 compression with 2mm deckheight.
Twin Weber 40mm carbs.
41mm Turbo Thomas header/exhaust (1 5/8 Inch).
Thats about it... very nice to drive in low rpms in a light beetle…
But also revs easy till 6000 rpms.
125HP
180NM

Here is a little bit more about it
http://cal-look.no/lounge/index.php/topic,8473.30.html