Time-Sert Installation Guide

modz · October 19, 2019

Firstly, full disclaimer: Ordinarily Time-Sert installs would be done by a machine shop and would also be done on a bare block. BUT I had neither of these options.

This thread is purely to assist others, and probably humour the rest of you.

Best source of reference is my old mate 50's Kid on youtube, who has a great vid: https://www.youtube.com/watch?v=kOfxg_Dto-U

For those who are interested, I did perform this myself and with success. Took my time, machined up guides to ensure straight drilling, used multiple drill bits etc

Scary? Yes. But completely do-able, and without a drill-press IF you are careful.

Would I use time-serts again? Yep absolutely. To the point I'd not put headbolts back into an alumium block without doing it. So much stronger.

All up this took about 2 hours end to end. And 3 whiskeys.

What you need:

10.3mm drill (sharp)
12.3mm drill (sharp)
M12 x 1.5 pitch tap
14x Timeserts on their own these are around $80 delivered from https://www.alleuroparts.co.nz/parts in Silverdale. Great team to deal with.
A range of drill bits up to 10.3mm and up to 12.3mm
A torch
An old vacuum or air compressor
Cotton buds
Good lighting
Patience
Whiskey

Preparation

Remove the head mount guides (2x) from the block with needle nose pliers.
Don’t bend them as they’ll be reused!
Tape over all of the block
Drop the head gasket back on and trace around the bolt holes
Cut out areas where the holes are (sharp razor blade or scalpel)

Drilling out the threads

Start with an 8.5mm drill bit drilling out the threads, move up in 0.3mm-0.5mm increments.
The depth of each hole is 46mm. Mark this on each drill bit (masking tape and a sharpie work) so you don’t over or under drill.
Take your time, start each hole slowly. The drill will naturally straighten in the hole – this is why using small incremental drills is essential.
Vacuum away debris whenever possible – aluminium shards go everywhere!
Have a whiskey.

Drilling the tapered collar

Time Serts have a tapered collar to stop them going deeper than necessary into the block. This collar is 12.3 mm
Once each hole is drilled out to 10.3, drill out the upper sections of each bolt hole to 12.3 mm.
Note: You ONLY want to drill 6mm deep. Again, mark your drill bits (or even better, use a drill bit stopper) and take your time.
Start with an 11mm bit and work your way up. This will be tricky!
Have a whiskey.

Tap the threads

Get some oil or cutting oil, and also pack the edges of the Tap with grease to help pick up any threads.
A 2 handed tap handle is best as this will keep your tap straighter.
Even better, is a Tap guide, which is about $8 USD.
Take your time.
Every 3 turns or so, turn the tap handle anti-clockwise to break the threads free. This keeps the tap clean to continue to tap.
Bottom the tap out in the hole.
Wind the tap completely out of the hole and repeat until all are done.

Clean up

Aluminum is non-magnetic, so magnets in the hole will be useless for debris. A vacuum doesn’t really work as there is no cylindrical force to lift the debris up.
A compressor will a little (and spray metal debris everywhere), but by far the best I found was buying 200 cotton buds and using about 10 in each hole until I could see the bottom of the hole clearly with a torch

TIP: Put a dab of grease on the end and it’ll sponge up the particles

Re-tap

Once the holes are clean, run the tap right down and back up in each hole to check for binding and to clear any debris from the threads.
Repeat the clean up with cotton buds

Guide reinstalls

Reinstall the guides in the block for the head. They will fit back into their original location.