You are not quite grasping the idea here are you?

 

Haven't got the files here but do as Norri says above and you will be able to download the pdf which is all you need in addition to the description in the post.

 

Do you still rent the head puller?

 

People local to me can borrow against a deposit (for damage and/or non return). But with me living in Norway you will find it rather expensive regarding transport ...........

 

Thanks Per, I built the instrument and are able to extract heads!
Rome, Italy

 

This is because your dimensions aren't accurate. The stud size of the cam housing is 5/16" (7.937mm). Accordingly, if the holes are drilled 9mm, the plate should drop on.

I blindly followed your dimensions and machined the plate on a CNC machining centre. The plate didn't go within a bull's roar of assembling.

Doing a rough measurement with a tape measure shows that the extreme dimension of 684 is close to 682. As the measurement system used in the manufacture was Imperial, the rough measured dimension of 682 is close to 26 and 7/8 inches.

Regards,

Brent

 

can you rent it to me plase!

 

Hello,
This thread caught my eye so i wanted to post my experience with this activity going back 14 yrs ago.

I wound up making a press plate out of .500 thick mild steel, measuring the bolt pattern demensions, then drilling and threading on a Bridgeport vertical manual mill. I bought grade 8 all-threaded rod and grade 8 nuts at the fastener shop and welded the nuts on to the cut to length press studs.

The cavitation and electrolysis from not changing the anti-freeze yearly was so atrocious, that i had both heads entirely rebuilt to the tune of $2000K.

By the time i pulled both heads off, the tool was expired.
The mild steel plate and machining had stretched itself beyond any more use, and the studs remained frozen, internal threads stretched and fatigued even with lubrication. It was a miracle they came off as clean as they did, but the cost, i wound up pulling everything out anyway and it would have made life such more pleasant including my back doing this on an engine stand.
I did this with engine in the car with the hood on. MISTAKE.
Three days per head, 8 hours per day, basically 24 hrs turning each press bolt a half turn at a time to evenly pull the head up and off without bending the head studs or reaming out the casting bores for the head studs, let alone damaging a head itself or at worse , CRACKING this cheap casting alloy material.
24 hours per head at a half turn per fastener,all in torque sequence.
That is called undivided patience on a very expensive automobile.

I found a shop down in Tacoma Washington "AllCast LLc." that was willing to do the work. He gouged out 75 % of the surface area with a burr getting back into the virgin raw casting alloy, then slowly TIG welded and flowed it all back in. They then went to a place called HeadsUp in Auburn Washington and they shimmed the heads, put them into the oven to flatten them back to datum , inclusive the cam journal alignment, then milled them back into flatness, then a valve job. They found one cracked factory valve that had an internal flaw that had manifested over 94K miles, i grabbed hold of it with a pair of common pliers and with a little leverage the piece broke right off the edge of the valve head.They staked back in two valve seats.
With all the reading i have done on the development of these heads, Jaguar Cars Ltd. could have certainly taken a different route as far as the material grade used in these castings and the tolerance fitting of these valve seats.

I don't have the dimensions or press pattern any more but i did find the stud drawing, these rascals are or were $20 a piece and at 54 fasteners i believe, there is a lot of money in bolts or rather studs.

Cheers,
Stür

 

Calvin. Do you still have the head puller?

 

Hi Greg,

Were you ever able to get a drawing of the hole locations? I sent a PM to Per but have not yet received a response.

I guess I could work with the PDF file he posted but I was hoping to get a CAD file to save me time in programming.

Let me know if you might have something.

Thanks!

Mark

 

Mark
Sorry, I was never able to make head or tail of what the file said. basically people of my age need paper and clear notation of what's what!

i bought, by sheer luck, a head puller from a firm in the UK last year. They are a TR specialist but had done some work as a favour to a customer on an E type. They had a made a few pullers and were selling them at a reasonable price (200 UKP), and I found out by sheer luck. Now I just have to pluck up the courage and energy to use it!

Greg

 

Hi Greg,

Thanks for the response.

No worries. I can make one myself. It just would have saved me some time if someone had already worked out the dimensions and had created a CAD file.

Mark

 

Hello Mark,
The drawing posted by Per is not within a Bull's Roar of being correct. I was half way through the process of digitizing the hole locations of an actual head when a colleague found the PDF file posted by Per. I abandoned what I was doing and used Per's dimensions in a program to machine a plate in a CNC machining centre. On completion, I went to fit it to the head only to find that some of the holes were out of position.

Not being accustomed to making mistakes with NC programs, I consulted Per's drawing and confirmed the coordinates in my program were correct to the drawing, and that the drawing is clearly incorrect to the actual hole coordinates of the head.

The only way the plate worked for Per, is that he drilled the holes for the Cam housing studs way oversize and he must have been bending these studs to get the plate to fit. He states in his post that he could only just get the plate down past the Threads of Cam Studs. This indicates that the Cam Stud holes are out of position, and would have sounded alarm bells had I read the whole post at the time. With the size holes he drilled for the Cam Studs, he should have been able to throw the plate on from a distance like a quoit.

I haven't got back to that project, but if you can wait a week or two, I'll digitize the head and post an accurate drawing.

Regards,

Brent

 

Hi Brent,

That would be great. I'm working on it now but it would be great to check it against your's and see if we came up with the same dimensions.

I made a proper drawing and model using the dimensions called out from Per's drawing but some of the numbers just don't look correct. If you would like a copy of my drawing PM me your email address. You can mark it up and send it back to me and I will make the corrections.

Thanks!

Mark

 

I recently tried making the simple ones listed in experience in a book. What I would up with was broken studs. The offset of the holes caused the plate to "****" the cam bearing studs. I then made plates for both ends of the head, that catch 4 can bearing studs, and push against 4 of the main head studs. I put the simple 4 hole one in the center. This worked like a charm. I will be glad to send pics, measurements if anyone wants them

 

Hello Mark,
You're wasting your time with Per's dimensions. PM sent.



The Cam Studs are 5/16" (7.937mm). Drilling 9mm holes should have allowed the plate to fall on if the holes were in the correct positions, not jam on the short threaded section.





Regards,

Brent

 

I have made myself set of 8 pulleys 4 for each bank of the engine for my 1994 XJ12. They worked beautiful! Naw engine works like new! If anybody need this tools I'm selling them on Ebay or make it your self also.Diagram attached in pictures!

 

Gents, I have been offline for a long time but have just got around to reread the thread plus new posts. The last measurements being off is no surprise although 2mm is more than expected. I did not use force to get the puller onto the heads nor were the heads damaged. However luck may have been working in my favour if the actual holes were 1/2mm off in the "right" direction. If anybody have made the puller to my drawing check which holes are a no go and drill out to a slightly larger dimension. Use a thick washer and all will be well. The whole point of my instructions were to make somthing that anybody could easily copy at home, warts and all.

 

Hello Per,
At 9mm, your holes for the Cam Housing Studs were already drilled way oversize for the 7.937mm (5/16") diameter that the studs are. The fact that the plate assembly was very tight for you, and you could only get it down as far as the threaded part (your comment) indicates that you must have been bending the Cam Studs (they are easily bent) to get the plate to fit.

The mistake I made on the day was not reading your Post; it was my colleague that found the drawing and handed it on to me and I blindly followed the drawing. The fact that you got the plate to fit indicates to me that luck was indeed working in your favor, and I suspect that you may have removed the Cam Housing, thus allowing the Cam Studs to bend from were they entered the Head and not only from the top surface of the Cam Housing. The better application of such a plate is to pull it down firm onto the top surface of the Cam Housing.

Regards,

Brent

 

Building the Legend | V12 Head Removal


Interesting read