PART 7 - CB Race Rods- How to Build a CB Performance 2017cc Builder’s Choice VW Engine

In this video I'm looking at the CB Performance Race rods -5.4. I'm checking the weights and tolerances of the big and little ends. To do this I'm using a few specialist tools - micrometer and bore gauge indicator.

[@johnfreeman1189]

Excellent content! Thanks for posting!

[@masbeetleboy9169]

Sounds like your going to have a stout motor, though I think it might be a bit overbuilt for the street.

[@tospicy4ya]

When’s the build coming ? You must be itching to get on with it?

[@aircooledanything2415]

It’s coming very soon. I’ve been having push rod tube problems. Waiting to resolve that before I can finish that post it is going to be looooong and full of fun mishaps hahahahaha. New post this evening.

[@bwm999]

The wear limit for the small end clearance is 0.04mm!. New spec has a super tight tolerance and is effectively machinist “slip fit” which is a hair over an interference fit.

[@aircooledanything2415]

Good to know. I need a guage that will fit the little ends.

[@bwm999]

Checked the Bentley manual. The new spec is 0.01-0.02mm. At that you should not be able to rock a fresh pin beyond a tiniest amount (pin measuring bang on 22.00mm), at 0.04mm you get a little rocking. So you can do it by feel. Also checked the VW rod clearance spec. That should be 0.02-0.07mm new, with a wear limit of 0.15mm. The side clearance of the rods (to the crank webs) is 0.1-0.4mm, with a wear limit of 0.7mm. Race engines are often set up a bit loose to reduce friction losses at the expense of lifespan. Thanks for doing these videos. I’m finding them very useful so please keep it up, even sharing the mistakes! 👍

[@aircooledanything2415]

@@bwm999 the pins were super firm In there. 👍

[@vpinhorn]

Never use loctite on ARP bolts. Only use the supplied grease!

[@aircooledanything2415]

Ooops. Too late. 😬

[@vpinhorn]

@@aircooledanything2415 I would be taking it apart and cleaning off the loctite before I ran it :) the loctite will mess with the bolt torque. ARP are very specific that you use only their lube.

[@aircooledanything2415]

@@vpinhorn blimey. That’s a bit drastic for me. Short block assembly is now complete. Yikes. I thought loctite helped with torque settings. I put both the loctite and their grease on. For my all plication as a daily driver, low revs and nothing serious with regard to hard driving I should be okay. I know for next time though. Thanks for the advice.

[@patrickmclaughlin6013]

@@aircooledanything2415 sticking my nose in here I wish I had split my cases and rechecked the innards while it was out rather then regretting it after I put the thing back in. That's where I am right now. vwdaren isn't so hot on lock tight on the crank or any internal parts, he says it can flak off after it hardens, but he does race his engines

[@aircooledanything2415]

@@patrickmclaughlin6013 Damn,sorry to hear that. What was the problem?

[@patrickmclaughlin6013]

I thought the rod bolts were not supposed to be reused after they have been torqued? Something about the bolts stretching? maybe that's if you run them in the motor for a while?

[@aircooledanything2415]

That would make sense. I know 356 Rod nuts are one time use only. Time will tell I guess. I hope it doesn’t cause a problem. 🤨

[@vpinhorn]

These are ARP rod bolts they are reusable. If you’re concerned, use a stretch guage

[@aircooledanything2415]

@@vpinhorn that’s good to know. Just the loctite issue that will give me sleepless nights now 🥺

[@vpinhorn]

@@aircooledanything2415 it maybe ok, but if it were mine and seeing the amount of time and effort in that I know you do on your projects I think I would be doing it right for peace of mind :) I’ve just checked on the arp website, they say either lube or loctite, not both.

[@charliemessenger6537]

Just keep weighing them until you get the numbers you want! I thought it odd that you were putting Loctite along with the assembly lube. I know you had done that elsewhere.

[@aircooledanything2415]

I know right!? I noticed that the numbers changed depending on where you placed each rod on the scale's plate. On the last round I put them all central and I liked those numbers, so stopped there. Hahahahahaha.

[@bedlamite42]

bend a stand out of wire so you can weigh the big end and small end separately, match both ends.

[@mikehammer4546]

Great info. Btw; are you sponsored by WD40 🤔

[@aircooledanything2415]

🤣 Sadly not.

[@vpinhorn]

Race engines have loser clearances than a street engine

[@bedlamite42]

Notch the rods so the oil leaving the journals get squirted to the bottom of the piston. From a vw service bulletin: thesamba dot com/vw/gallery/pix/933841.gif

[@patrickmclaughlin6013]

hot tip, Thanks do you cut that grove on both sides or just one?

[@aircooledanything2415]

That’s a great tip. All of those little details can make a huge difference.

[@bedlamite42]

@@patrickmclaughlin6013 Both sides, and I usually use a round needle file and don't leave sharp corners. You can do something similar to the rockers with CB's rocker arms too along with the HVX oil system mods: bobhooversblog.blogspot dot com/2007/05/hvx-mods.html