1766 CC ENGINE BUILD UPDATE

[totallyconfused]

Hi,

Just an update on the engine build.

Put the crankshaft plus new bearings in the engine case....
I installed the Enkle 100 cam shaft.....
put the case back together and all was good.

Put the new oil pump in and all was NOT good....
Engine would not turn....

The cam shaft was hitting on the back of the oil pump.

Split the engine case again....ground some off the rear of the oil pump housing and off the top of the camshaft bolts.

That did the trick....

Engine case now back together and spinning.

Have just put the bigger 1776cc pots on and checked the compression ratio.

I used a handy ratio calculator app...

http://www.csgnetwork.com/compcalc.html" onclick="window.open(this.href);return false;

Bore Size : 90.5 mm
stroke length : 69mm
Headgasket bore : 0 (no gasket)
Headgasket thickness : 0 (no gasket)
Combustion chamber volume : 59 CC's
piston Dome : 0 (as Flat Piston Head)
Piston Deck Clearance : 1.43 mm (measured with piston at TDC)

Got a compression Ratio of 7.508 : 1.

Aircooled .Net state "Enkle 100 Cam compression Ratio range is 7.5 to 8.25 : 1"

so all seems good to go ahead and put the cylnder heads on.

Will have to work out the piston rod lengths once the head goes on.

Will put some pictures up in a moment but need to get them off my phone first.

Cheers.

[937carrera]

Just a few questions / thoughts:

Is this a CT engine upgrade ?

That deck height looks a bit big to me which is why the static CR is down at 7.5, mind you the best you will probably get with those heads and pistons is about 7.8:1. Are you sure you don't have any compression rings in the head or barrel rings on the bottom ?

That engine calculator misdescribes combustion chamber volume as Total Displacement Volume as well, but you probably realised that

I don't understand what you mean by "will have to work out piston rod lengths once the head goes on" either

but it sounds like you are having fun

[totallyconfused]

Here are the pictures.

The one of the piston and barrel shows the Deck cleatance.

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[totallyconfused]

Hello,

Many thanks for the response. Any thoughts or comments welcome.

Yes, it is a 1600 CT case.

I haven't put any shims/spacers on the pots. Do you think 7.5 : 1 ratio is too low? The haynes manual says the original 1600 ratio is 7.4 : 1.

The cam shaft I have put in is slightly tweaked. So not sure if that will effect the pushrod length, or not?

I have got some new stronger pushrods which need to be cut to length.


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[totallyconfused]

Here is a shot with head on. [SMILING FACE WITH SMILING EYES]

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[937carrera]

It's looking very red

Is the cam designed for hydraulic tappets or are you moving to solids because it isn't ?

That'll dictate the type of pushrods you need to use, and is there a reason why you want / need to fit non OEM ones, especially ones you have to "cut to size", as the ends are profiled.

I'm generally a stock / OEM type of guy across all types of vehicle, unless it's for a race application, as a lot of the performance upgrade stuff isn't. But, as the Yanks say, there's no substitite for cubic inches so the 1776 conversion has always been popular.

I agree the CT was 7.4 as stock, but as your cam is good up to 8.25 and I can't see other constrints such as heat dissipation being an issue, why not take advantage of the higher CR, you'll get more torque that way (note I said torque)

Let's hope Sarran1955 wanders by as he knows much more about the CT and mods to them than I do, just some thoughts as you are posting your pictures.

[totallyconfused]

Hello,

Oh, you noticed its red!!! [FACE WITH TEARS OF JOY]

I wasn't sure if the cam would run with hydraulic followers so have got some manual ones.

I read somewhere that be better to have stronger pushrods with the cam. Can't remember where, and may be overkill, but have got them now.

So to increase the compression ratio I need to lower the deck height...is that right? I am guessing that means machine work to either lower the pots in the case, or shorten the pots?

Am slightly out of my depth here!!!! As the saying goes....a little knowledge can be a dangerous thing. [SMILING FACE WITH SMILING EYES][FACE WITH TEARS OF JOY][FACE WITH TEARS OF JOY]

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[937carrera]

The cam lobe profiles are different between cams designed for hydraulic / solid tappets, so you need to ask the manufacturer which they are designed for. Being as it's a 1776, therefore Beetle upgrade, I suspect you will need to move to solid tappets. I've never even heard of cutting down pushrods so my first reaction is , but it may just be my lack of specific knowledge. I hope your cam manufacturer can answer that question

To increase the CR, yes it would be machine work, most likely to take a little off the bottom of the barrels so they slide in further. (you can always shim it back that way too). Rule of thumb, you don't want to much below 1mm deck height.

Where did you get your head cc's from, 59cc seems a lot, are you still using CT heads, if you measured them yourself did you remember to deduct the volume taken up by the barrel walls ? It's important for assessing the CR as you know.

Don't take my musings as gospel, I know my way round type 4 engines, and others, reasonably well, but have never done the Beetle type mods. Others have I am sure so specific experience is more valuable.

[totallyconfused]

Hi,

The head CC measurement came from the manufacturer....they came from the states. I didn't think about the barrels reducing the CC's....so it may be less. Is there a way to calculate the CC's with the barrels included? I have seen a thing online where you fill the combustion chamber with water and measure how much it took to fill the chamber. Don't think that will include the barrel bit though...so is there a way to deduct that after? If the CC's are less, I am guessing that will increase the compression ratio?

I agree, the cam is for a beetle/type 2 engine so thats why I thought better to go for manual lifters. [SMILING FACE WITH SMILING EYES].

The manual lifters may alter the pushrod lengths....I have an adjustable pushrod tool that allows you too set the right length and you then cut pushrods to suit.

Got the tool from Niel at Boatyard Buses. He is very helpful.










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[937carrera]

You set me thinking and I realised I have a stripped CU engine lying around and went to have a look at those heads, it's been a while since I examine an Aircooled head and I have been doing head checks on WBX engines more recently.

The head design is similar, except that the WBX has a significant dish and small head volume, whereas the Aircooled has a small dish and a large head volume. Looking at the head design I'm pretty sure that the 59cc will just be for the head cutout. You can cc the heads yourself, and then use Pi to adjust for the barrel thickness. If you read Sarrans thread he measured his aftermarket heads at 53cc

I take it you are just going to fit the barrels direct to the head, no compression seal. If there is going to be one, then you need to add that to the compression volume.

You realise you are going to have to put up some photos of you cutting your pushrods and the tool now

[totallyconfused]

Thanks alot for the info.

Thats great to know. Will look up Sarran thread. I think I have the same heads as Sarran so will come in around the same I guess.

Will slot that figure in the app and see what compression ratio that gives.

I wasn't going to put a compression seal in and just put the head straight onto the barrells. Not sure if thats wise, or not. [SMILING FACE WITH SMILING EYES].

Will take some pictures when get to setting up the valves/rocker's.

Once again, thanks for your comments and thoughts.

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[937carrera]

A standard compression gasket at 0.7mm will add 4.5cc to the compression volume, so that will reduce the CR from what you already calculated. It will also increase the piston to head clearance to 2.13mm which I think is quite a bit too much.

Old schoolers use compression gaskets, aftermarketers tend not to

Look at Sarrans thread, he did a 1679cc engine, so the heads may not actually be the same, measure, check, recheck before final assembly. It's a lot of work to find out the engine doesn't perform as you expect because of a CR or clearance issue

Happy to take a look at the components if you provide links

[sarran1955]

Hello,

I've been off doing VW meets...

Q: what is the distance between the top of the piston and the top of the cylinder, at TDC, measured on the axis of the piston.

I did say at the beginning of this project that fitting beetle bits to CTs can cause problems....

Did you check this:



then this:



How to do the deck height test:



The problem with cutting down cylinder height etc, which is often done on big bore T1 motors, is that the
engine width changes, and so exhausts and heat exchangers get more difficult to line up properly.

As for Engel 100 and 120 cams, I don't see how you can use them to advantage in this set up.. unless you are fitting
a lightened flywheel and twin carbs...not enough rpms, not enough newton-metres.

Cordialement,

[totallyconfused]

Hello Sarran,

Not so much a problem, as a challenge!!!

Will double check the deck hieght as measured it at the edge, rather thsn centre. Will also check the barrel lengths.

Wont be till the weekend, but will let you know how it goes. Will also measure the head Combustion Chambers....just to make sure the figure I have is right.

Hope the vw meets went well and you had a good time.

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[totallyconfused]

How do,

Have remeasured my deck height....as per Saran's picture. Thanks for that Sarran.

Got a deck height of 1.22mm.

That gives me a compression ratio of 7.6 :1.

Have cut a bit of perspex to seal of top of combustion chamber and will check the 59cc measurement given by manufacturer when I get a chance. (See picture).

Took a pucture of adjustable push rod too. Will do that once I have measured the combustion chamber.

Enjoy your weekends.



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