Originally posted by Oslo: I'm curious to find out if anyone knows what the pitch and size of the valve cover bolts are on both the 2.8L and 2.5L fiero valve covers?
I have found a cool replacement part that people may be interested in but I need to know if it's going to work or not.
Thanks!
A replacement part for the 2.8L valve cover bolts would be great because mine are ratty, as is the washer for each bolt, and in particular, the "sleeve" for each bolt. By the way, I know The Fiero Store doesn't have any new valve cover bolts because I called them just a week or two ago about that very subject.
In any case, based on some old 2.8L valve cover bolts I've just measured, the diameter of the shank of the bolt itself, just below the top of the bolt's hex head, is 4mm.
Each bolt thread is 1mm apart from the next.
The length from the start of the bolt to the start of its head is about 1 inch or 25mm.
So far so good.
The bolt itself is the easy part
However, what complicates things is that for each valve cover bolt, there also is a 17mm washer and a 12mm high sleeve with an integral horizontal "circular collar" (15mm in diameter) above its cylindrical part (that has a 7mm outside diameter) into which the bolt is inserted. The sleeve and the washer are there so that the entire bolt, which is fairly narrow, cannot pass through the the larger holes in the valve covers themselves, which would make it impossible to tighten the valve covers with just the bolts, because those valve cover holes are fairly wide by comparison, about 7/16" or 11mm in diameter.
Sorry, but I've no pics, just the aforementioned measurements I took for a 2.8L Fiero V6.
In any case, a replacement part for the Fiero's valve cover bolts, as well as their needed sleeves and washers would be great!
Oslo, I forgot to note that the "12mm high sleeve" I mentioned three paragraphs above has no threads at all; it is smooth.
In any event, have you any updates on the potential "replacement part" you mentioned you found for the valve cover bolts on both the 2.8L and 2.5L Fiero valve covers?
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03:36 PM
TopNotch Member
Posts: 3537 From: Lawrenceville, GA USA Registered: Feb 2009
Originally posted by KurtAKX: I think M6x1.0. I'll check if I get a chance tomorrow.
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Originally posted by TopNotch: I think that's correct. If you go to Lowes or Home Depot, you can get some nice stainless steel ones that will look great.
TopNotch, your suggestion about trying Lowe's or Home Depot for some stainless bolts is an interesting one. However, I don't think the "6" in the "M6x1.0" measurement that KurtAKX cited is correct, at least not for the 2.8L V6 engine.
Assuming the "6" refers to the bolt's shank width in millimeters, and the "1.0" the bolt length under the head expressed in inches, I get "M4x1.0" instead of "M6x1.0."
There also is the added complication of the washer and the smooth, "12mm high sleeve" into which each bolt must be inserted before being able to fasten down the valve covers. That aside, though, some stainless bolts probably would look great (as long as one bought the right size).
Originally posted by Bloozberry: Here's how metric bolts are classified:
M4 X 1.0 X 25 (9.8)
M4 = metric 4 mm diameter 1.0 = thread pitch 25 = shank length in mm (9.8) = grade
I have some 2.8L valve cover bolts lying around the shop I'll go measure before the evening's over, and add a photo of what the spacer looks like.
Excellent!
If you can (because mine are almost half disintegrated), please double check the measurements I posted for what I described as the "12mm high sleeve with an integral horizontal `circular collar' (15mm in diameter) above its cylindrical part (that has a 7mm outside diameter) into which the bolt is inserted." (The photo of this which you mentioned obviously also will be a big help.)
Also, besides my parts' ratty condition, to measure them I was using an ordinary ruler rather than a micrometer, which I don't have, and your reference to "the shop" suggests to me you might have a micrometer to help ensure accuracy of measurement.
Here's what the 2.8L valve cover bolts look like. They're actually M6 X 1.0 X 25. I didn't measure up the sleeves but I can add that info tomorrow. The sleeves are crimped on in such a way that they freely spin on the bolts, but cannot come off. Also, there's a little rubber washer that fits under the sleeve to seal the hole in the valve cover.
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08:27 PM
fierogt28 Member
Posts: 2962 From: New-Brunswick, Canada. Registered: Feb 2005
Guys, check with GM if they are still available. Any fiero V6 that could be in junk yards, these bolts would be a plus to grab.
90% of the V6 fieros I've seen, the engines are not running or even worse...blown. The junk yard shouldn't refuse anyone taking parts off here and there. If your looking for something free, they will refuse most likey. They are in business to make money, not give free-be's every day.
Hope this helps...
------------------ fierogt28
88 GT, loaded, 5-speed
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09:01 PM
TopNotch Member
Posts: 3537 From: Lawrenceville, GA USA Registered: Feb 2009
The 2.5 cover bolts don't use the sleeves. I put the Lowes stainless ones on my duke, even though you can't see them (SD4 valve cover). I'll take a look at Lowes to see if they have anything to replace the sleeves. They have quite a bit of nuts-and-bolts hardware. It'd be nice to have stainless ones on my V6 car.
In my Internet searches last night for the V6 bolt, I found several sources for hexagonal, metric, 6mm, stainless bolts with a 1.0 pitch, but all were too long for our purposes, a minimum of 30mm instead of the 25mm we need.
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Originally posted by TopNotch: The 2.5 cover bolts don't use the sleeves. I put the Lowes stainless ones on my duke, even though you can't see them (SD4 valve cover). I'll take a look at Lowes to see if they have anything to replace the sleeves. They have quite a bit of nuts-and-bolts hardware. It'd be nice to have stainless ones on my V6 car.
I'd like that as well for my V6, but I suspect that finding the appropriate "sleeve" for the valve cover bolt may be more difficult than finding the bolt itself.
Before you check out Lowe's for these parts (and I'm certainly interested in learning what you find), you may want to wait until Bloozberry has had the opportunity to post the dimensions of the bolt sleeves he has. From the photos he posted above, it's evident to me that the V6 valve cover bolt and sleeve assemblies which he has are in far better shape than my junkyard-sourced ones which I'd measured earlier. Therefore, I'd think his measurements of those parts would be more accurate than mine.
I found something that may substitute for the sleeves. Brad hole tee nuts, size 1/4-20 x 1/2. You could drill out the threads to make sleeves out of them. The washer head diamater on these is 3/4" (19mm). The sleeve length is 1/2" (12.5mm) The sleeve diameter seems a bit small. Lowes only sells SAE size tee nuts, but the company that makes these (Hillman) also has metric ones on their website. They have a size listed as M6 x 11 x 19, but the thread pitch is not given. (The picture on the link I gave shows both pronged and brad hole tee nuts. You'd want the brad hole ones.)
Edit: Lowes only has the stainless tee nuts (14-20) in 5/16" or 9/16" long. So they'd either be too short or too long. I'm still investigating this.
[This message has been edited by TopNotch (edited 01-12-2010).]
Thanks for posting the sleeve's measurements, []Bloozberry[/i].
Separately, as you may recall, the bolt measurements I had didn't come close to those which you and Topnotch posted, but now at least I know why. The diameter of my junkyard-sourced bolts is much too narrow for an M6 bolt, slightly too narrow for an M5, but a bit too large for the M4 bolt I'd thought it was. In fact, it's apparently not even a metric bolt that the salvage yard erroneously had sent me for the V6 in the first place. Instead, it fit perfectly for something which I believe Lowe's called a "10-24" (whatever that is).
Topnotch, I thought your suggestion for using the metric Brad hole tee-nuts as a substitute for the sleeves rather clever. However, that washer head diameter of 19mm that you cited for this fitting appears to be about 2mm too wide to fit within 4 of the 6 circular indentations surrounding the 6 holes for the valve cover bolts in each V6 valve cover. That 19mm washer head diameter wouldn't be a problem at the 2 ends of each valve cover, but it likely would be about 2mm too wide for the recesses in each valve cover that surround the other 4 holes.
Nonetheless, that idea inspired another one.
Why do we need these sleeves in the first place? Yes, we need to cover the 11mm holes in the valve cover for the bolts going into them because the stock bolt head isn't wide enough to do that, but why not use bolts which can do that instead of using bolts which can't, necessitating a sleeve?
I found that http://www.totallystainless.com offers several different styles of size M6 x 1.0 x 25 bolts that are in the stainless steel we're looking for. I didn't find them at Lowe's, but two of these (totallystainless.com part numbers 1-2211 and 1-2311) have a 13mm integral flange just below the bolt head. That 13mm flange presumably should be wide enough to cover the 11mm bolt holes in the V6 valve cover, thereby enabling one to tighten down the valve cover without any sleeve, should it not? Also, the hexagonal head of the 1-2211 bolts even takes an 8mm socket, which is the same size wrench as for the Fiero's stock hexagonal-head factory bolts, is it not?
What say you, gentlemen? Do you think these stainless bolts would work?
The sleeves are there as stand-offs to prevent overtorquing the valve cover onto the head and deforming the gasket. When you tighten the bolts, you're actually bottoming out on the spacers which leaves the valve cover semi-free floating on the gasket. If you didn't have the sleeves, you'd squish the gasket out before the bolts were tight enough not to work themselves loose.
This business of finding aftermarket valve cover bolt sleeves and washers apparently is a challenge even greater than I'd thought it was earlier.
Based on your explanation above, Bloozberry, those sleeves are not readily dispensable.
Also, I see that those sleeves apparently have to fit within washers, which in turn are slightly recessed to accommodate the sleeves, and those washers cannot exceed 19mm in diameter so that they'll still fit within 4 of the 6 circular indentations surrounding the 6 holes for the valve cover bolts in each V6 valve cover.
A larger washer head diameter, one wider than 19mm, wouldn't be a problem at the 2 ends of each valve cover, but my measurements of the valve covers indicate that washer can't be more than 19mm to still fit within 4 of the 6 circular indentations surrounding the 6 holes for the valve cover bolts in each V6 valve cover.
That sleeve also has to be able to accommodate a 6mm-wide bolt, and besides that, the sleeve apparently still has to be 12mm high, based upon what you said above, Bloozberry.
Maybe you or TopNotch feel otherwise, but frankly, I despair of locating an aftermarket sleeve having all of those properties.
Originally posted by Bloozberry: There has to be someone out there that makes similar sleeves... maybe a large fastener company like Spaenaur.
Thanks for the suggestion, but if they have those sleeves in stainless (I couldn't find them), it appears Spaenaur requires large minimum orders, like at least 100 pieces for things associated with relatively small items like M6 bolts.
I found a source for some polished, stainless steel, hexagonal head, M6 x 1.0 x 25 bolts with an integral, 13mm circular collar that would cover much of the Fiero's black sleeve, which you'd measured to be 17mm.
Could one re-use the stock Fiero sleeves with these new bolts, or would that not work because of the crimping you'd mentioned earlier:
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Originally posted by Bloozberry: The sleeves are crimped on in such a way that they freely spin on the bolts, but cannot come off.
I'm not entirely sure how you would go about getting the sleeves off. You can see a little divet in the center near the top of the sleeve of the bolt to the right of my picture. There's three of those little divets per sleeve so I'm guessing you'd have to drill them out with a tiny drill bit to get the sleeve off. The reason you want the sleeves to be attached to the bolt is so that when you remove the valve cover (especially the front one), the little pieces don't accidentally fall into the valve train and end up fouling something.
well the product that I discovered that would be a really neat replacement for Fiero valve cover bolts only comes in: 5/16 inch x 18 TPI 1/4 inch x 20 TPI These sizes are really common for many other vehicles, but I guess not the Fiero.
It would work if you wanted to tap the heads, but that's not realistic for most people. I guess it won't work for us.
------------------ Top Line Group Automotive -Aftermarket accessories for the Fiero www.TLG-auto.com
Originally posted by Oslo: well the product that I discovered that would be a really neat replacement for Fiero valve cover bolts only comes in: 5/16 inch x 18 TPI 1/4 inch x 20 TPI These sizes are really common for many other vehicles, but I guess not the Fiero.
Thanks for looking into this anyway, Oslo. I'd hoped for success because whether I've purchased new or used parts for my Fiero from you, I've been pleased with the end result.
In any case, as I mentioned earlier, it looks like the "sleeves" which Bloozberry posted a picture of earlier will be the primary obstacle to overcome if one is looking to obtain new sleeves for some new stainless bolts, as I am:
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Originally posted by Bloozberry: The sleeves are crimped on in such a way that they freely spin on the bolts, but cannot come off. Also, there's a little rubber washer that fits under the sleeve to seal the hole in the valve cover.
I think I've found a source for correctly-sized stainless hex-head bolts for the valve covers, but unfortunately, I've not found any new sleeves for those bolts (whether stainless or not) that are in the dimensions needed (like the used ones Bloozberry pictured).
Does anyone know of another name for such "sleeves" that might prove useful in my locating a source for some new ones on the Internet?
For example, upon showing them the picture Bloozberry posted, a couple of hardware store personnel referred to the "sleeves" (rightly or wrongly) as metric "shoulder bolts." What say you?
