Intake/Exhaust Manifold R&R

[55 Fargo]

Okay, gonna bite the bullet, and try and get the manifolds swapped on my 55 Fargo 251 engine.

I have a nice donor set, bead blasted and painted, heat riser is working too.

I do dread this job, as I have never got a set of manifolds off to date without breaking a stud or bolt.

So this hopefully goes relatively smooth, or can be a nightmare....wish me luck

[BigDaddyO]

Luck.

[55 Fargo]

Luck.

Thanx Big DaddyO, I am approaching this job with some trepidation......

[mrwrstory]

You got heat?  If any studs are stubborn, heat 'em real good and melt on candle wax.  Can save your good nature!   

[55 Fargo]

Hi Bill, the studs aren't too bad, on Canadian long block engines, it's the 2 long 3/8 bolts that go through the centre section, that break off, then the fun begins...

[Dodgeb4ya]

I've done a quite a few of few of these manifold jobs myself.

When those two center bolts break they are a real PITA!!

 

The two center bolt heads broke off at the manifold leaving corroded weak and thin studs on the last one I did.

Sometimes lube/wax and or a Oxy Acetyelene torch will enable a broken bolt or stud to be removed- my last flattie job-wasn't easy at all...broken bolts, broken drill bit and frozen cone nuts to the studs-just a lot more time to do the job!!!!

[55 Fargo]

Hey Bob, I feel your pain. Would you beleive the donor manifolds I bought this winter. The Guy I bought these off, he removed 2 sets from 2 engines, and not 1 bolt or stud broke, go figure, what luck or was it luck?

These were from farm grain trucks, and maybe they were not so corroded, or something.

I have heard of thos who broke 1 bolt, and reinstalled the manifolds minus 1 bolt, and all was well, not sure I would do that though.

I plan to try this job possibly later this week.....

[RobertKB]

Good luck, Fred. I broke one of those long bolts. Eventually got it out and replaced it with a long stud with a bolt on the end. Some of my engines have a bolt and some with the long stud. I used a brass nut on the end for easy removable if I ever do it again. 

 

[55 Fargo]

Thanx Rob, will need the luck, I do not mind doing the work, it's just I do not have great tools to deal with a broken stud/bolt. Once a stud is broken an oxcetylene torch can be real handy, but don't have one. I have considered taking it to a general shop I deal with, but if it ends up being an 8 hour job, thats $500.....

Edited May 25, 2014 by Fargos-Go-Far

[T120]

I've also broken a middle manifold stud ...As shown in Bob's photos,I drilled mine out as well.I used good quality cobalt drill bits starting with a pilot hole.I didn't have a right angle drill at the time, fortunately there is a very good tool rental shop nearby where I rented a Makita right angle drill.I was able to remove the stud without damaging the threads in the block. 

[Bobacuda]

I broke the front generator mount bolt in my block.  It had about 1/2" of shaft showing.  I tried heat and vice grips (and a stud remover), but the best I could do was chew off about 1/3rd of the protruding shaft.  A friend of mine brought his mig welder over, we took a washer that was about the diameter of the shaft, placed the washer over the shaft and welded the shaft to the washer.  Then we put a nut over the shaft and welded the nut to the washer and the inside to the shaft.  It gets red hot, so we let it cool a few minutes and put an impact wrench on it (90 - 100 lbs).  The first two attempts broke off more shaft till we were down to about 1/8th" of shaft showing.  We repeated the process and the third time was charm. 

 

This saved me from having to load the truck chassis on a trailer, or pulling the engine again, to take it to a local mechanic that has been very good at getting broken bolts and studs out.

[55 Fargo]

Glad that worked out for you Bobacuda, lot of patience,time and energy.

I have 2 choices, do the job myself, not a bad job, but I do not like dealing with broken studs in my home shop, not equipped like a machine shop by no means.

Or I let a local small shop do it for $80 per hour, under my supervision, they have everything to deal with broken studs etc.

I did this job on my old 47 Chrysler, I drilled off center, big trouble, then hired local machinist to come over with his right angle drill,cobalt bits and taps, that cost a $150, and it was tapped 1 size over.

Will decide next week what I will be doing, hot weather is no fun with a stuck heat riser in the wrong position......

[55 Fargo]

1 question for those who have done a manifold swap.

I have a really nice donor set, bead blasted painted, heat riser in good working order.

I do not intend to split the intake from exhaust prior to installing. Have any of you done the same thing?

[DJ194950]

Suggest,

Look inside and out at the gasket between intake-exhaust. Holes? Maybe time to take a chance break bolts and replace as needed. Repair if needed or not.

All looking good and Maybe last a while?

Put a straight edge across the mounting flanges- first across straight and x'ed the faces of the mounting surfaces of the block side.

If the are very level, great!.

If not, replacing the intake to exhaust manifold bolts loose (replaced if needed) Allow them to settle in with the new gaskets when tightened and Then the intake to exhaust bolts get tightened., ( per repair manuel.)

 

DJ

[Young Ed]

If the mounting surface checks out for flatness go for it. With your long block why not break them loose of each other? You have no danger of the bolts getting stuck in the intake like the 23" one.

[55 Fargo]

Hi Ed, they check out really well for trueness. I could remove the 4 long bolts, but would rather not, if possible.

How are the 23 inch manifolds diffeent?....

[Young Ed]

Hi Ed, they check out really well for trueness. I could remove the 4 long bolts, but would rather not, if possible. How are the 23 inch manifolds diffeent?....

The exhaust is attached with bolts into blind holes in the intake. They ALWAYS break off and then you are stuck removing broken bolts.

[MBF]

I was in the same situation a few years ago.  While I had the manifolds off I took them apart to replace the gasket.  I heated the blind hole area of the 4 corners of the plenum until they got red hot.  I was able to walk all of the bolts out w/o breaking a single one. The machinist told me that this would work because the cast housing and the steel bolt don't heat at the same rate, and that is what allows this to work.   It's easier to do now than to have to take it off again in the future.   Whatever you do, neverseize the studs, use brass nuts wherever possible, and try to stay patient.   Good luck-you'll get it done.   Mike

[NiftyFifty]

If you really want pain, try and take those 4 bolts out...you'll definitely need a torch then. Honestly I've had three off and no issues..those two long studs seem to break mid way I find if they do and then its just some heat, PB blaster and vice grips or a stud remover. When I rebuilt my 251 I used all grade 8 coated bolts, they have worked great, and I'm 3 years in and no issues at all. I check them each spring and they all are free enough to give a tiny move tighter....but I only check cold..don't want the heads snapped off later.

[55 Fargo]

4mula, I am on your side with the seperating the intake from exhaust, been there, but did it on the bench with some heat and PB Blaster.

I did break off 1 of the 2 bolts on the last job I did, it sheared off close to the blcok, so no fun.

I am pulling the manifolds very soon, and will see what adventure I will be on in the process.

I also used grade 8 bolts, on the last job, and all is well there too.

[Bobacuda]

The three attempts to weld to the stud and remove it took less than 1 hr of time.  No drilling, cobalt bits, or ruined threads.  It took longer for my friend to come over with his welder and set it up than it did to remove the broken bolt.

 

I first saw this on Fast & Loud.  I later saw it on a different automotive program.  The "different program" used a large handled box-end rather than an impact wrench.  The heat transferred from the welded area to the broken bolt had to be significant.  I tried using a 1/2 inch socket with a breaker bar on the two failed attempts - the impact wrench worked much better. I think the hammering of the impact was more effective than a constant pull.

 

Had the third attempt failed, then I would have taken it to the mechanic for the labor intensive drilling, tapping & etc.

 

Good luck.

[NiftyFifty]

Welding a nut to the stud is a good option, and I use that removal technique all the time, actually had to use it to remove all the locking lug nuts off my truck, but that was welding a nut to the stripped out locking nut, rather then the stud. The issue with that is ensuring you have no gas anywhere close to your weld, and with the fuel line in that general vicinity, its good to be extra careful. Also of course if your welding on the vehicle, unhook your battery as you can fry alternators etc with a welder.

[Dodgeb4ya]

I also welded a washer and nut to one of the short damaged studs. Broke the stud off at the block. Ended up drilling it. My specialty that I'm really pretty good at.

Welding the nut and washer is a good way out of a bad situation with broken bolts. Not 100% though.

[48Dodger]

i

Edited May 27, 2014 by 48dodger

[HanksB3B]

i

 "i" what ? I passed out at 2:46 AM and never finished this post ?

 

Goodnight in the morning Tim,

 

Hank