Mi16 Con Rod Bolts

[Andy 105 1 Cars]

I am rebuilding my Mi16 engine to more or less a standard spec( details in the 'projects' section.) I have just installed the crank, rods and pistons and am now having a moment of doubt over the rod bolts. I have used the old ones . Should I have replaced them ? Advice please?

Andy

[Tom Fenton 1,541]

Yes I would replace. If one breaks then it creates carnage. Either standard replacement or ARP uprated.

[TAG 25 1 Cars]

Last time I looked at prices on Servicebox, the rod bolts were around £100. ARP can be had for slightly more than that on eBay, hence I shall be going ARP when the time comes (requires slight modification to rod)

[petert 586]

If you can afford it, buy new. Otherwise for a street engine I'd be happy with 2nd hand ones. I've never had a rod bolt let go from failure on its own. Plenty of times from oil surge however.

[Andy 105 1 Cars]

Thank you. As always, very helpful

[Miles 331 1 Cars]

Used old std ones and never had issues but if you do need to replace then the ARP for the cost is the way to go for the same price, ignore Ebay prices as normal as there is a huge mark up, I do them if needed

[Andy 105 1 Cars]

Thank you. All mine looked in good condition and angle tightened without drama. It was only afterwards that I began to doubt their integrity, but for no compelling reason, hence my query on this forum. My bigger concern was the fitting of the pistons into the liners. If I were doing this again I would definitely get an old liner machined as per the Petert suggestion, or at least in the first instance see if a better ring compressor is available .

[petert 586]

You can buy tapered ring compressors fairly cheaply from eBay, Summit, etc.

[Mikey S 29 1 Cars]

If it helps ease your mind...... I did big end bearings on my Mi16 back at the beginning of last year along with a new oil pump and I reused the old bolts. It gets its neck rung when ever I go out in it! it'll be fine.

 

Mike

[Andy 105 1 Cars]

Thanks. It does!!

[Jon_Bmw 13]

It is the most important bolt in the engine...

 

Unless you have the history of the bolt (stretch data from new) then it should be replaced. This is true for decent bolts like 625 arps let alone a stock pug bolt!

 

For the amount of time you have put into building this, I would have thought 100 quid on 8 bolts is a no brainer.

 

Hopefully all will be OK though! I've liked the build report so far.