GSX750ES : Inserting valve guides

[dpascal]

There's a shop in my area that specializes in engine heads. They took off the 16 valve guides from my engine head and I gave them 16 NOS valve guides.
The part # is 11115-49290 in this drawing:
http://www.alpha-sports.com/suzuki_parts.htm?fpg=/spst/1983 GS750ES/15.htm

When trying to fit in the first valve guide they ended up breaking it.
I asked them if they freeze the valve guide while gently heating the head block and they told me that the old valve guides are 11.05 mm in width vs. 11.35 mm of the new ones and there is no heating/freezing process that is going resolve a difference of 0.3 mm.
1. Did I get the wrong valve guides or is it that the 0.3 mm difference in width is acceptable and was caused due to 31 years in which the old guides were squeezed ?
2. Assuming a difference of 0.3 mm, how should the new valve guides be inserted ? The guys at the shop offered to precisely fine-drill the guide holes to remove 0.2mm and I wonder if it should be done ...

 

[Rensdw]

I can't answer your question but what self-respecting engine shop is just going to blindly press those things in without taking measurements, what exactly makes them "specialists"?

Now that the head is damaged you prob. end up overboring the guide hole anyway.

 

[tkent02]

Just curious, the shop specialize in motorcycle engines or car and truck engines?

 

[TxGSrider]

I'm not a metallurgist, but I'd think it'd take allot of force to break a cast iron guide pressing it into an aluminum head. I think you are really lucky the head didn't crack... and they should've realized it wasn't going to work before it broke.

 

[gearhead13]

Do you have a manual for your bike? It says in there that there is a special suzuki reaming tool that you are supposed to use to open up the guide holes to fit the new guides. New Suzuki guides are oversize. You can get new guides that dont require reaming from the aftermarket (APE)

 

[Nessism]

Do you have a manual for your bike? It says in there that there is a special suzuki reaming tool that you are supposed to use to open up the guide holes to fit the new guides. New Suzuki guides are oversize. You can get new guides that dont require reaming from the aftermarket (APE)

Yes, this. Read the manual.

 

[dpascal]

The shop which specializes in both cars and motorcycle was indeed suppose to measure the guides before pressing them. They took responsibility and said they will deduct the cost of the guide from the price we already agreed on.
I just read the manual and there's a rimming tool for 11.30 mm which AFAIK will do the job.
I can get it from a local Suzuki main dealership.
Is this the right tool ?
http://www.cmsnl.com/products/valve-guide-reamer-113mm_0991634561/#.WAZE2_l96Uk

 

[Nessism]

You might want to talk to the shop before ordering. They may already have that size.
Goodson and similar shops sell reamers too so you might want to shop price.

 

[dpascal]

Be sure that I will not spend 183 Euros on this tool
Technically speaking ...
If the guide is 11.35 mm, I need the 11.3 mm reamer, right ?

 

[dpascal]

Ed,
Is 11.30 my magic number for the 11.35 valve guides ?

 

[Nessism]

Ed,
Is 11.30 my magic number for the 11.35 valve guides ?

I can not comment on the sizing without doing research.

 

[GregT]

My rule of thumb when fitting guides is to use .002inch interference fit.

.004inch is for most purposes equivalent to .10mm so .002inch will be .05mm.

The reaming job should be carried out very carefully as it will be very easy to end up with an oversize hole - after which you get into making up oversize guides....

 

[dpascal]

Good. So 0.05 interference fit will be achieved if for a 11.35 mm (over-sized) guide I will use the Suzuki 11.30 mm reamer...

 

[Guest]

I would think it would beneficial to get the head to a qualified shop to do the repairs. A hand reamer isn't accurate enough without some kind of support. The results will be lots of grinding on the seats to get them close. Just my opinion, Jerry

 

[gearhead13]

Might be cheaper/easier to just buy aftermarket guides that dont need reaming. Also the new bronze guides last a lot longer.

 

[dpascal]

I wasn't able to get a reasonably priced high quality reamer and I came up with an idea which seems to be the most simple to precisely implement : Machining the new guides to 11.05 mm.
How come nobody suggested that ? Am I missing a difficulty or a risk involved ?

 

[GregT]

I wasn't able to get a reasonably priced high quality reamer and I came up with an idea which seems to be the most simple to precisely implement : Machining the new guides to 11.05 mm.
How come nobody suggested that ? Am I missing a difficulty or a risk involved ?

It is possible but over 16 guides you WILL stuff up one or two....
The amount you're taking off is so small that effectively you're polishing it off.
If you want to try it, put the guide between centers in the lathe so as to maintain the OD parallel to the bore.

Ask the engine recon shop about honing the head to suit the guides. They may have a setup which would be more accurate than reaming.

It is a pity you've already bought the guides as it is much simpler to get aftermarket guides which press straight in.

 

[dpascal]

The guys at the shop told me that they will be able to achieve much greater accuracy of they machine the guides them-self because they are easy to center.
Assuming that working on 16 guides will cost me less than a third of what would cost me to buy new guides, I decided in favor of this option.