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Location: Portland Oregon
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Quote:
Originally posted by Mark McClure
Steve- if the stock heads are good as is I will put a stop to the port & polish! Thanks for your example. What is the web mac used close to with reagrds to the GE grinds.
Hi Mark:

The GE-80 is the closest to the WebCam 171/149's.
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Steve Weiner
Rennsport Systems
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Old 11-10-2005, 05:40 PM
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Thanks Steve....that is what I have sitting on the banch! Did you run twin plug on the race motor or just single and race fuel.

How tractable was it down low.

Cheers

Mark....
Old 11-10-2005, 05:58 PM
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hmmm...I just had my heads done, new valves, springs, guides at Whyms. How did you determine it was a bad job?

thanks
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2007 911 Turbo - Not a toy
1985 911 Cab - Wife's toy
1982 911 3.2 Indiash Rot Track Supercharged track toy
1978 911 3.0 Lichtbau toy "Gretchen"
1971 911 Targa S backroad toy
Old 11-10-2005, 06:37 PM
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Quote:
Originally posted by Mark McClure
Thanks Steve....that is what I have sitting on the banch! Did you run twin plug on the race motor or just single and race fuel.

How tractable was it down low.

Cheers

Mark....
Twin-ignition, indeed,....

It made good power from 5000-7500 and had the typical little "hiccups" between 3500-4500 as ALL carbureted race engines do,...

Exhaust systems make a HUGE difference in drivability and throttle response, as well as HP. 911 motors are quite sensitive about this.
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Old 11-10-2005, 06:54 PM
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An ex employee of Bob's looked at them....you could see daylight passed the valve. When I rang them Bob admitted that he had a new guy doing the work and said somthing like "I guess he is not as good as I thought"...nor is the QC!!!!

IT does surprise me though since two people recommended him.

Cheers

Mark.......
Old 11-10-2005, 06:58 PM
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Crap.
I'm having mine twin plugged @ PR (or their outsourcer) tomorrow. Will have them check the Whyms work...
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1985 911 Cab - Wife's toy
1982 911 3.2 Indiash Rot Track Supercharged track toy
1978 911 3.0 Lichtbau toy "Gretchen"
1971 911 Targa S backroad toy
Old 11-12-2005, 08:41 PM
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This is a reply to to the problem with the cylinder heads for Mike Mclure, from Bob Whyms.

After we had sent the overhauled heads back to Mike he rang me to say there was a problem, one of the valve guides had been fitted incorrectly. So I agreed to pay to have the heads sent back to us so I could inspect them and rectify the problem. In the mean time Mike rings back to say the bore kit he is using is not the same compression ratio as the one that the heads were originally machined for and what should he do. I suggested Burnie from Rams Heads might be able to weld the heads up to get the compression right and re port them to suit the bore kit he was using, so Mike rings Burnie and the heads are sent to Rams. After a few weeks Mike rings me to say that Burnie informs him some of the valves aren't seated properly in the heads. What should he do? As the heads are at Rams anyway I suggest it would be easier if Burnie fixes them up while they are at his premises rather than having to send them back to us and then back to Burnie again thus expediting the delivery of the heads back to Mike. I would then pay Burnie for all of the costs incurred. As I explained to Mike (not in the careless attitude and way he has portrayed me on this current thread) our Head machinist has been contemplating retirement for some time and we have had someone in training to take over his position, unfortunatly as in any business and in life people do make mistakes and I have taken the steps to ensure this problem doesn't occur again, this has been evident in the countless engines we have re-built since this incident that we have had no problems with. Except for the inconvenience Mike has not had to pay for any of the rectification work. In any service provided to you from a business if you get a poor job and you don't have the problem rectified at no cost to yourself then I guess you should let people know (but always inform them of the whole story not just the parts that suit you) but in this case the problem has been rectified. I have been in business for 35 years and stand by all the work that comes out of my premises and have done for all those years.

Bob Whyms
Old 11-13-2005, 02:08 PM
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Well, I have to say I was very impressed by an experience with Bob Whyms today. I had my heads done at his shop 2 months ago. He want back into his records, found my invoice, and called me on my mobile today.

He offered to do whatever needed to be done, include coordinate with another mechanic, to check the work was OK. He is sending a courier over to my work tomorrow to pick them up and have them tested.

Its a shame Mark had an issue, but sometimes the measure of a relationship is how you deal with things when they go pear-shaped. I have to say I was impressed with Bob's proactiveness and follow-through once the problem came to his attention.


John
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2007 911 Turbo - Not a toy
1985 911 Cab - Wife's toy
1982 911 3.2 Indiash Rot Track Supercharged track toy
1978 911 3.0 Lichtbau toy "Gretchen"
1971 911 Targa S backroad toy
Old 11-14-2005, 04:55 PM
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Bob,

JohnJL is obviously happy! It was not clear but did John contact you or did you feel that you had to recall your work for inspection? All credit to you for your proactiveness. Since there is obviously a question here I will have my old valves speced to see if I really did need to replace the full set. I will give you a call ASAP on this matter.

Sorry to read that you feel the comments made have been an attack on your business. Not so, you have paid for the work to be redone. You obviously had a QC issue during a transition period and you have outlined the exact circumstances and trail of events.

I did use your services due to two seperate very good recommendations. You are not, as it has been suggested, being hammered on the internet. You actually come out of this with an "advertised" high level of customer service!

Mark....... ( not Mike ! QC issue? )
Old 11-17-2005, 10:12 PM
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If a business fixes their mistakes that should be good enough for anyone.....no one is purrrrfect,,the perfect comes when the customer is satisfied...............Well.. some will never be.......but ya try to eliminate them b4 the work order starts.......and NO I am not trying to insinuate that here.......in this case everyone ought to be happy!!!!
Old 11-18-2005, 09:06 AM
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Just got the heads back after having the guides redone, port and the 98 mm chamfer welded and machined back to 95........well that was the intention.

Having measured the combustion chamber I have found the following measurments......(mm) as you can see they are quite oval!

Vertical Horizontal
#1 97.92 96.24
#2 97.23 96.97
#3 97.80 95.89
#4 97.46 96.04
#5 96.73 95.67
#6 96.55 96.36

I have made no other measurments. So the question is..........if running 95mm cyl how uniform should the combustion chamber be and are these figures acceptable.

Thanks

Mark......
Old 11-25-2005, 04:51 PM
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Are they Nikasil's?
A machine shop would be able to tell you if that is within specs and what should be done with them.
I don't get the porting-issue. '78's have larger (39mm) ports already.
And about the valves. How much mileage on them?
I had heads done with 140k miles just recently; all guides were replaced but all the valves were good and received a new 3-angle grind.
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Old 11-26-2005, 07:48 AM
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Hello, Mark.

Thiwsndoes not sound good I'm afraid..

it is not powssible to say whether the whole head is distorted , the welded portion has been poorly machined ( a special setup is needed to do this repeqatably head after head), and whether the chamber volumes differ..

Quite alot of work is obviously needed to measure all this accuratley..it not at all simple..

And obviously more work to remachine etc ..

It will be much cheaper to get better heads IMHO..
And you will not be worrying about the weld distortion progressing diuring thermal cyleing in use..

Kind regards
David
Old 11-26-2005, 02:16 PM
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Hi,

I am not sure if the heads are distiorted or not I have not measured anything other than the diamater of the chamber. I need to know the spec the heads had originally.

The Cylinders are Nikasil and within spec. The valves are worn and needed replacing.

Also something else I noticed is that the valves have been shipped back seperate to the heads. It appears as though they have not been lapped into the seats, even though the guides have been replaced.

So first things first, what is the diamater of a standard 3.0 78 chamber, and what are the tolerences.

Thanks

Mark......

PS......I did consider getting replacment heads but these are already twin plugged and the expence of rebuilding was less than replacement value.
Old 11-27-2005, 01:59 PM
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My exp is always (almost) throw away exhaust valves...their job is probably the toughest one in the Eng. Anything but new on rebuild is....not in the best insurance policy . you want cooling margin left and its not there on a reground valve......not as much as new.And consider how many times they have opened and slammed the door so far?? YIPES !!
Old 11-27-2005, 03:23 PM
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Afterburner 549,

If the guides are replaced should the avles be reseated and if so should they be kept in the same port or can they be moved between ports.

Cheers

Mark.....
Old 11-27-2005, 04:22 PM
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if the guides are touched in any way the seats have to be redone to match because the angle will be slightly diff (angle of valve- to seat relation ship)
Old 11-27-2005, 05:10 PM
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Thats was my understanding! so It looks like I will have to examine the valves and seats to see if they have done any work on them?

Thanks

Mark.....
Old 11-27-2005, 05:13 PM
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caveman test- put valves in, no springs, fill ports with solvent or alcohol, flip head over (right side up) holding the valve to the seat by the stem......you should have no shadow for 30 sec. I am guessing you will see a pass fail right away . It will either run out or be in good shape.
Old 11-27-2005, 10:02 PM
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This all sounds strange. Kangaroo job?
When heads are send out for a valve job, the guides are replaced and the valves get ground/lapped, the springs get tested, and the heads come back assembled.
The mating area for the cylinders gets a slight shave if needed.
What is the sense in getting the heads back with the valves on the side?
Are the valves new?
Are the springs tested?
Are the heads the same height now?

Am I missing something here?
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1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.
Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".
Old 11-28-2005, 05:06 AM
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