JBugs - 1971 VW Super Beetle - Engine Build Series - Clearancing Pistons & Setting Compression Ratio

[@CTmoog]

Oh man. I'm going to have to watch this a few more times. Some of that went right over my head. Great video!

[@Sam_Mebane]

Don't worry CT, the video isn't going anywhere!

[@dakotamonroe9746]

As someone who is will be doing their first engine build (2007/2110, not sure yet) this video and the others like it have been invaluable. Thank you!

[@daos3300]

don't forget to mention the cylinder has to be torqued before measuring deck height.

[@brettfoster6786]

Great video . thanks for the advice .having a great time building my motor -

[@pjdillon7982]

I've always heard deck hight is supposed to be between .040 and .060 ideal is .050 and compression should be adjusted with chamber cc

[@Sam_Mebane]

It all comes down to the CCs of the chamber and the piston diameter. Talk to 10 different builders and you'll probably get 10 different answers.

[@vintage76vipergreenBeetle]

👍 Nice info.

[@miltona09]

Do you need to check the end gap of the piston rings when they come as a kit like that?

[@Sam_Mebane]

It doesn't hurt one bit, but for a mild performance engine it isn't crucial. If your are building a high compression or turboed engine then absolutely.

[@JayDubCustoms]

You're building an 1800cc motor and say that 7 to 8.5 is an ideal compression ratio. Is it ideal for this size motor only or all bug motor sizes? What's the best ratio for a 1600 daily driver? Thanks!

[@JBugsVWParts]

That is across the board, regardless of engine size. Grant it, with proper tuning and fuel higher compression ratios can be run but keep in mind, VW built the engines at 7.5 or less.

[@monkeysuncle2816]

@@JBugsVWParts What is considered the "safe range" for compression ratio? Are there different measures one can take to make the upper end of said safe range safer?

[@Sam_Mebane]

@@monkeysuncle2816 We wouldn't recommend anything over 8.5 to 1.

[@muzzcovw7674]

@@monkeysuncle2816 Totally depends on cam selection

[@anangelshero0410]

Interesting that you used metric input for calculating the deck height but chose standard measurements in setting it. Was there a reason for this?

[@Sam_Mebane]

It's just the way most calculators are set up and the shims are always listed in standard measurements.. The math is the same either way so it just comes down to preference.

[@matthewreese2199]

Did you have any extra vibrations from the clearance cuts on the piston? I am going to need to do the same I have a 78mm stroker with 87mm pistons apparently type A and I should have gotten type B

[@JBugsVWParts]

As of now with about 3 hours of run time on the engine we haven’t seen or heard anything off from the engine, no. Cutting the skirts on the pistons is relatively common and as long as the pistons are cut symmetrically and balanced there shouldn’t be any ill effects.

[@secondlooksformen3836]

Thank you, J. Bugs, for sharing so much info at no charge! Learning a lot that I did not understand - so thank you. Great videos.

[@billmiller9901]

Can you please tell me where the oil sensor is on a 1971 type 3 1641? I cannot find it

[@Sam_Mebane]

It is located on the oil cooler.

[@russellp1982]

I've always read that minimum deck height should never be under .040

[@Sam_Mebane]

It all comes down to the CCs of the chamber and the piston diameter. Talk to 10 different builders and you'll probably get 10 different answers.

[@muzzcovw7674]

Correct. You risk contact anything below that.

[@rwebdaddy]

So you measure with the copper shims on top of the head then you put the steel shims at the case. Why not use the head shims??

[@Sam_Mebane]

Because we needed more height than head shims allow and case shims are more commonly used than head shims.

[@rwebdaddy]

@@Sam_Mebane the copper head shims help seal the head also.

[@Sam_Mebane]

@@rwebdaddy which is why we used both.

[@VolksStokes]

Some say to hand tight those studs onto engine case like you say, but some say to torque these to 22 lbs/inches if 10MM chromoly. When i tried to torque these, they keep going deep inside engine. Can someone please help

[@Sam_Mebane]

We thread them in by hand.

[@VolksStokes]

@@Sam_Mebane Thanks Sam. Whew! Close call to ruin the engine case, glad i stopped when it kept going and made no sense at the time

[@pepi12xbr]

Way no sealant between shims and cylinder base? I always use it and added an extra 0.010 to the math.

[@Sam_Mebane]

Not during mock up, no. We use sealant when we do the actual assembly.

[@vwmadness1591]

Why would you use a copper shim on a street engine when you have to always re torque the head

[@Sam_Mebane]

The copper shims are used as a head gasket of sorts. Either way, we re-torqued the heads after about 3 hours of run time.

[@rygelrygel1832]

@@Sam_Mebane It looks like, from the video, you used one steel shim and one copper shim to make up the .080" between the case and each cylinder? I did not see where you installed the copper shim between the cylinder and the head in the video unless that is in another video. Thank you.

[@Sam_Mebane]

@@rygelrygel1832 when the heads are installed, yes. The copper shims install at the top, between the cylinder and the head.

[@brettfoster6786]

I need some help . 2110 cc. 74 strocker crank , head's have 52 cc . how much deck hight do I need ? Looks like I need to have the cylenders cut down . tork motor in a 63 bus ? I have deck hight of mm3.46. Inch 0.135.5.

[@JBugsVWParts]

Some of your information seems off. A 2110cc engine would have 90.5 pistons and a 82mm stroke crank. If you have a 74 crank and 90.5 pistons, you’d have a 1904cc engine. That may be where you’re having problems in calculating. With your current configuration (assuming you have 90.5s) you’d have 7.4 to 1 compression. If you wanted to bump the compression up then yes, you’d have to cut the cylinders down a bit.

[@brettfoster6786]

@@JBugsVWParts thanks for Your help. The 82 crank broke and I got a 74 from Roger at century . trying my best .

[@brettfoster6786]

7.4 to 1. Will that work ? How much should I have cut off . for best running . I dont drag race. Just camping and VW shows ABC

[@JBugsVWParts]

7.4:1 is right in line with what VW originally set the compression ratio at. It could be bumped up a bit for performance but at the end of the day, it probably won’t be worth the time or cost at the machine shop. I’d leave it be and get on with the assembly.

[@johnnyharrison7973]

You go to fast.

[@Sam_Mebane]

Playback at .75 speed if it's hard to keep up.

[@bentkarma83]

No way I will cut anything engine related.

[@ArthurSperotto]

lol don't build an engine then.

[@timavery7984]

No thanks -will stick w a stock engine.

[@ArthurSperotto]

Then why watch the how-to video on building a stroker motor, and then take the time to make a pointless comment?