Ferrari Forums banner
1 - 5 of 5 Posts
G

·
Discussion Starter · #1 ·
I've run into a brick wall

I've run into a brick wall trying to figure out how to remove the cylinder heads from an 85 308 QV motor. From what I understand from searching the net, the aluminum of the head reacts with the steel studs when coolant is present and they fuse together. The bond between the block and heads seems incredibly strong & I don't want to wreck or warp them by trying to pry them off.

I thought this would be a perfect situation where Ferrari would have made an extremely expensive tool to do the job, but I was surprised to find that there was never one. I have seen talk of people who have made them, but no details on how to do so.

Does anyone have any cool tricks to do this task, or plans for making a puller rig? I have fairly limited metal fabrication stuff in my shop. Pretty much just hand-air-power tools, oxy-accetayne torch, mig welder, plasma cutter, chop-off saw, etc. It seems like a puller should somehow put upward force on the head, and downward force on the studs, with an even force, but the studs are hidden in that cavity. Any help would be GREATLY appreciated.

-Kevin Pearson
 
G

·
Discussion Starter · #2 ·
Kevin,

Welocme to Ferrari T


Kevin,

Welocme to Ferrari Talk!

Pulled a many 4-valve heads, with "rarely" a problem...On the 2-valve cars, this appears to be more of an issue.

Do you have the engine out of the car? his helps!
Are you sure that you've got all 10 (?) nuts removed? I know, obvious, but you never know...

Typically, I'll remove the cams...keeping the plugs in and then turn the engine over. Or, use compressed air in the spark plug holes to break the head gasket to head seal...

And I've used oak wedges to break the headgasket seal...though you've got to "pry" evenly, so not to jam the head on the studs. The first couple of mm are the toughest.

Where are you in NH? I live outside of Manchester and would be more than willing to share my experience with you...

Regards,
David
 
G

·
Discussion Starter · #3 ·
Quite common even on the 4v mo

Quite common even on the 4v motors. They are getting old so the corrosion has had many years to develop. The tools generally made will not work on the 4v motor because the head studs are not exposed in a straight line to the top of the motor. Compressed air in the cylinder is fine but will only break the head gasket fire ring seal, a seal that is almost invariably broken just by removing all of the head nuts. The best process we have come up with if the heads are really stuck is to heat the head through and through with a rosebud attachment on an acetelyne torch to 300 or 325 degrees. At that temp the head will have loosened its grip just enough to get some movement of the head. The 308 and 328 heads overhang the ends of the block just enough to allow a thick (1/2 inch or better) block of aluminum to seat well on a strong piece of the head so a large hammer can be used to coax the head off. It will teeter totter on the studs when you switch ends so some material will need to be inserted in the growing gap between the head and block as it is worked up. We use roof flashing because it is very cheap and individual sheets can be slipped in one, two or three at a time as needed. It distributes the load over a large area so no damage will be done to the surface of the head or block.

You will not get more than about 10 minutes working time before the head will need to be reheated.

It can be very time consuming and we have had motors where we used the contents of entire large bottles of Oxy and Acetelyne to get one pair of heads off. In bad cases it can take a pair of people an entire day or more to get one head off. Losing patience will result in expensive damage so take your time.
 
G

·
Discussion Starter · #4 ·
I'm sorry to butt in like

I'm sorry to butt in like this, but I'm compelled to say how impressed I am, and always have been, with the technical knowledge and advice on this website. I think that is what ftalk founder JRV wanted most for this forum. I am a do-it-yourselfer, and on many occasions both Mr. Feinberg and Mr. Crall have rescued me when I was in over my head with my first Testarossa. I make notes in my shop manual, and download postings from these gentlemen whenever I can. We are very lucky to have them here. There...I feel better, Thanks for letting me get that off my chest.

P.S. Brian...it is GOOD to see your still taking time from your busy schedule to help those in need.
 
G

·
Discussion Starter · #5 ·
Thank Jeff!

We do what we n


Thank Jeff!

We do what we need to do to just keep on having fun...I did drive up North to take a look at this engine. Hey...I needed an excuse to take the BB out. What I found really odd was that the block is dated 1978, yet it had 4-valve heads on it and it's out of a 1985 308QV GTSi. I was lead to believe that the 2V and 4V blocks were not interchageable...and that 4V blocks didn't start production until 1982 or 83.

Anyhow, it's always nice to meet another owner in person and admire these cars.

Take care Jeff,

David
 
1 - 5 of 5 Posts
Top