Loose Bolts - ZR-1 Net Registry Forums

Jim Nolan · 04-16-2007

Just an FYI I was pulling my plenum and injector housings so I could send them for port and polish and the first 4 outside bolts on both sides of the injector housings were loose. I mean they had zero torque on them. I think this is the first time this engine has been torn down this far. It's a '92.

04-16-2007

It happens, I've had a few motors that have been like that. Might cause a small vacuum leak that is hard to track down. They are not torqued down very hard in the first place.

A26B · 04-16-2007

Quote:

Originally Posted by Jeffvette

It happens, I've had a few motors that have been like that. Might cause a small vacuum leak that is hard to track down. They are not torqued down very hard in the first place.

If low torque results in loosening over time, then I would recommend application of a low strength Loctite or similar brand product. That type of vacuum leak would be a real bear to track down....almost like your secondary shaft seals Jeff. Wow!!

Locobob · 04-18-2007

Quote:

Originally Posted by A26B

If low torque results in loosening over time, then I would recommend application of a low strength Loctite or similar brand product. That type of vacuum leak would be a real bear to track down....almost like your secondary shaft seals Jeff. Wow!!

Use a low strength Loctite when you reassemble - an ounce of prevention

Paul Workman · 12-26-2009

I found my IH bolts in much the same situation - first time I pulled the plenum. One was little more than finger tight! A little BLUE Locktite seems to be doing the trick.

I suspect too that after using LT or other goops one should run a thread chaser thru the bolt hole to clean out the threads of any residue before reinstalling the bolt and torquing it down in the interest of uniform bolt pre-load. (Or, at least I would on an iron head. running a tap thru an aluminum part gives me some pause, how-some-ever.).

P.

tomtom72 · 12-26-2009

Yea I noticed the same on my 90 when I had to replace my bad OE injectors. You should have seen how loose the CCVB cover bolts were also. Made a mess of my valley!

W/pump T/Q = 26 N.m or 20 Lb/ft

I/H bolts = 26 N.m or 20 lb/ft, my 90 FSM has no pattern diagram.

Plenum bolts = 26 N.m or 20 lb/ft, see pattern in FSM

T/Body bolts to plenum = 26 N.m

CCVB cover bolts = 10 N.m or 89 In/ lbs

Tom

04-16-2007	#1
Jim Nolan Join Date: Jan 2007 Location: Florida Posts: 241	Loose Bolts Just an FYI I was pulling my plenum and injector housings so I could send them for port and polish and the first 4 outside bolts on both sides of the injector housings were loose. I mean they had zero torque on them. I think this is the first time this engine has been torn down this far. It's a '92.

04-16-2007	#2
Jeffvette Guest Posts: n/a	Re: Loose Bolts It happens, I've had a few motors that have been like that. Might cause a small vacuum leak that is hard to track down. They are not torqued down very hard in the first place.

12-26-2009	#5
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Loose Bolts: IHs as well... I found my IH bolts in much the same situation - first time I pulled the plenum. One was little more than finger tight! A little BLUE Locktite seems to be doing the trick. I suspect too that after using LT or other goops one should run a thread chaser thru the bolt hole to clean out the threads of any residue before reinstalling the bolt and torquing it down in the interest of uniform bolt pre-load. (Or, at least I would on an iron head. running a tap thru an aluminum part gives me some pause, how-some-ever.). P. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

12-26-2009	#6
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Loose Bolts Yea I noticed the same on my 90 when I had to replace my bad OE injectors. You should have seen how loose the CCVB cover bolts were also. Made a mess of my valley! W/pump T/Q = 26 N.m or 20 Lb/ft I/H bolts = 26 N.m or 20 lb/ft, my 90 FSM has no pattern diagram. Plenum bolts = 26 N.m or 20 lb/ft, see pattern in FSM T/Body bolts to plenum = 26 N.m CCVB cover bolts = 10 N.m or 89 In/ lbs Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member