Community Forums

Daybreaker · 09-21-2014, 11:06 AM

Hi all Im fairly new here and live in the uk. I have a Daybreak 3270 yr 2000 with a 7.4 petrol converted to run on LPG. We love her and she is called Daisy as in " Driving Miss Daisy" Sad aint we. Anyways we have had loads an loads of trouble in the 3 yrs we have owned her the latest is that the exhaust manifold has blown/cracked. After 3 days of spraying the bolts with Plus Gas I attempted to remove the first bolt. It sheared off of course it would. I don't hink I will be able to drill out and use a easy out do to its location and fear I may damage the head. Im thinking how hard is is to remove the head and do it on a workbench? Anyone ever done this? Im fairly skilled, ex aircraft Tech and now a heating engineer /plumber. Haqve worked on cars in the past (rebuilt a classic E Type Jag) which I know is nowhere near as complicated as this beasty. Moan... the manifold bolts are only 1/4 dia. Hardly man enough methinks.
Thanks in anticipation
Bill

Skip426 · 09-21-2014, 11:24 AM

Welcome to iRV2.

Cylinder head Re & Re on the big GM V-8, is far less complex than that of a Jag, I-6, overhead cam engine. Access and weight of the parts will be the real test of your abilities.
Parts supply could be the biggest part of the problem. Gaskets and studs.
But if you have a supplier for the manifold, gaskets shouldn't be too much of a problem.
JMHO: If you end up having to remove one head ; do both.

Once the intake manifold and one head are off, second side is only another couple of hours work.
Hate to go through all the work on one side, then have to go back in next year for the other side.

EDIT: A second though, I always have them. If the manifold cracked, it could be from the, extra exhaust heat of the LP and the valves could be in trouble too, check all parts closely.

KJINTF · 09-21-2014, 12:08 PM

Had one of those "E" Type Jags with the 12 cylinder engine - stupidest thing I EVER did was to sell it way back in 1975 - as I remember it leaked oil and had the Prince Of Darkness electrical system but was fun to drive and looked COOL!!!

Regarding your 454 chevy engine - as stated above take both heads off. I found the hardest part of the job was access with the engine in the rig you will need to become a noodle and have a cheery picker at hand as well as a friend the heads weight close to 75lbs each. How many miles on the beast? Hope it's not an old carb model. Most of them cracked exhaust manifolds over the years, be happy you do not have the ford 460ci with a 750 cfm carb what a pain that thing was - Was a happy day that thing left my property NEVER to return

Parts for the 454 can easily be found on line - not sure what suppliers you have in the UK (surprised a bit it still includes Scotland)

jsides · 01-02-2015, 07:32 AM

Do not take the heads off!!! You will only open up a can of worms. Do not try to drill out bolts with manifolds on. You could screw things up royaly! I have done manifolds twice. It can be time consuming but its not hard. Jack the front of mh up put on jack stands. Take front wheel or wheels off turn wheel hub back or forward to access manifold. Get a small seat with wheels on it and roll right under the body panel. If you dont have the wide track workhorse it will be easier. Take off heat shields. Loosen exhaust pipe. Proceed to undo the rest of the bolts, if any break too bad, not all will. They are 3/8 16. You said you are fairly skilled, great no problem. Dill 1/8 hole in center of bolt all the way through, keeping drill straight, till you hit the gap at bottom of the bolt and bottom of hole. Spay wd40 or similar product into hole. Proceed to drill out bolt or bolts with increasingly larger drills. Do use easy outs!!! They break! If you break one you will might have to take head off. That will be a real pain. Some bolts will come out easier than others. When you get the manifold off you will notice the holes on the ends are bigger than the ones in the center. They are made that way. The manifolds expand and contract, thats why some bolts break.

Davel · 01-03-2015, 12:16 AM

Another method requires a welder to attach a nut to the broken bolt. The heat will generally loosen the stuck bolt and it will come out. I would put ARP studes back in rather than regular or oem bolts. They are available at speed shops like Jeg's or Summit. They are much better material.

Good luck,
Dave

jsides · 01-04-2015, 05:48 AM

Some bolts break off flush with the head, some the head comes off. Welding a nut trick works good. Flush with the head is harder to do. Thats when you have to start drilling. ARP studs will work probably easier to get in the UK. The GM bolts are ok also, but they are not cheap. There are four bolts that are used with 5/16 x 1/2 long threads on the back end that are used to hold spark plug shields on. Back in the day we took them off cars with headers or manifolds they were a pain. Lots of air flow no problem. On a mh i would try and keep them on. With all the shrouding it gets hot around the motor. You need all the help you can get to keep plugs cool.