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Do you want to buy a set of NEW CIH Head Bolts?

  • Yes, five sets or more of ten please (I'll contact to confirm number)

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  • CIH-Six Owners: Yes, one set of 14 please

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  • CIH-Six Owners: Yes, two sets of 14 please

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Discussion Starter · #61 ·
Hmm. This changes everything. Dave, if this turns out to be true, I will refund your money immediately. If you (or anyone else) still want the Gr. 8.8 bolts, I will suggest that you deal with the vendor directly.

I checked my old head bolts, and they are definitely marked "10.9". And Bob's comment to me was:
...while the later style are throw-away stretch bolts that are grade 8.8 and have a normal 'Allen' style drive head
I just e-mailed the vendor to request he double check his remaining inventory. I am afraid that if this is the case, I do not expect that this group buy will happen. I'll let you all know as soon as I hear.
 

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sorry, I know what I'm doing. I already looked and I have no problem. Hit me I'm in. single build with a set of spares. honest I looked at it before. no kidding 2 sets for one motor. Lets go, some of us knew from the beginning.

Kick the tire, light the fire

Pull it out, have a look where Bob is on the list. If you F the build then get 2 sets.
 

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Old Opeler
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Old Eyes ..

Just back from my Workshop (3.00am)
After very careful examination of the new Head bolts the number stamped on them is in fact 9.8 (Nine point eight). Had to get out my Loupe' and get some bright light on to several of them but it is definately "9.8"
I will have no hesitation using these bolts myself as they are a quality item.
They are specifically made for the 2.8/3.0 litre six cylinder motor from 1978 onwards and are the same thread as 1.9L four -cylinder ones but are slightly longer. Which is far better than being shorter! They will need to be cut down to the correct under-head length for use with the 1.9L cylinder head, of course.
Here is a couple more pics showing them compared to 1.9L bolts:
 

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That's good to know. I've been watching the progress on this and the box going to Canada will be a heavy one.

Keith you still in?

One thing I'm going to add, Keith is a very honest individual and this is starting to take on a pretty big proportion. Pay for it up front and don't make him foot the bill alone. That's not exactly fair
 

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Is there any problem with going to Class 12.9 Hex Head Bolts?
 

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markandson said:
Is there any problem with going to Class 12.9 Hex Head Bolts?
With hex-head bolts you may not be able to get a socket on them while the cam is in place. That's the reason for the reliefs cast into the camshaft body, for tool clearance while installing/removing head bolts.

I had some high strength ARP head bolts made for Opels years ago, and even though it was a 12-pt. external head on the bolts, the fit was too tight. So you had to bolt the head in place before the cam was installed, and remove the cam before untorqunig the head. Not a big deal for initial assembly, but for racing use where teardowns are frequent it added another degree of difficulty to the mix.

HTH,
Bob
 

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That's why every builder has been on this. It's like putting a couple steaks in with a pack of wolves and then wonder where they went. I full set of torx bits is only 20 bucks. A new set of head bolts is priceless.

Keith if you need help here in the lower 48 just say the word.
 

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Keith, I just noticed. 25 states and over 600 bolts and well that is getting up there.

Word to the wise. if you feed a shark all you get is a hungry shark that swims better.
 

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Torque Talk ......

1.9L Head Bolts - 8.0 kg-m (Hot) 58 lb-ft
10.0 kg-m (Cold) 72 lb-ft

3.0E Head Bolts - Three Stages:4.8/8.0/10.0kg-m 29/58/72 lb-ft

The other advantage of having slightly longer under-head length is that hardened washers can be used under there ......

GBP15 - or less! - for NEW Head Bolts (plus postage) * They who hesitate are lost.
 

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Discussion Starter · #71 ·
Thanks Jim, for being the "Guinea pig" here. I am sure glad that you bought those first sets before I ended up with a garage full of bolts that nobody wants (get it? "nobody" wants the bolts! :D I made a funny!)

OK, The Engineer in me feels compelled to look at the pluses and minuses:
1) They are weaker than the OEM bolts, but stronger than the "one-use-only" later-model bolts. This is a minus, but maybe not as much as I first thought.
2) they are longer, which is good "why"? A bigger concern than having not enough bolt thread is bottoming out in the block holes, so you would almost certainly have to chase the block threads (a good idea anyway, and I just bought a tap to do that), and probably also cut the bolts down or install hardened washers. A bigger minus than a plus, although the washer idea kind of appeals to me. Something about distribution of load, and less bolt-head-friction torque (or at least more "manageable" friction).
3) The Torx-head is certainly better than the OEM 12-point. Not as readily available as an Allen-head, but much easier to find than the OEM 12-point tool, and grips MUCH better. A definite plus in my mind.
4) These have un-threaded shanks that are a bit shorter on the long bolts, but MUCH shorter on the short bolts. Maybe not a big deal, but a small minus? It just "seems" like they would be inherently weaker with threaded shanks versus the un-threaded shanks on the OEM bolts. Maybe not?

RallyBob, what do you make of all this? Is this OK, or just a waste of time. Or something in between? Please be honest, or at least provide a couple of perspectives on my comments above.

I have to say I am a bit pissed about this. I SPECIFICALLY asked the vendor "...are the bolts Gr. 8.8 or 10.9?" and he said they were Gr. 10.9. Not that I gave him the Gr. 9.8 option, but DOH! the number of digits are two, not three! So not only are they the weaker material, but they are also longer.

Frankly, I was originally very interested in these bolts, as I have two engines to put together, and there are at least three other CIH's being built in the Calgary area. Now, maybe not so much...

So here is what I suggest. I would REALLY like to hear Bob's opinion on these bolts first. Then, if Bob doesn't launch the whole idea into the heavens, I will zero the poll, and start a new one from scratch. The vendor had offered me the 14-bolt kits for £9.00 a set (plus shipping etc.) if I ordered 50 sets or more. I have responded with an offer of £10.00 a set for 10 sets or more. If there are at least 10 orders after all this, then I will carry on. If not, members are welcome to do what Jim did, and just buy them direct at £14.99 a set.

Bob???
 

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kwilford said:
Thanks Jim, for being the "Guinea pig" here. I am sure glad that you bought those first sets before I ended up with a garage full of bolts that nobody wants (get it? "nobody" wants the bolts! :D I made a funny!)
well nearly keith :D :D
sorry no help on the bolts but an oppinion that its only a slight drop and just below the multi use bolts strenth but still way above the 1 shot wonder bolts we all have in our new cars (what 1980 on for a stretch bolt use )
 

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Sorry for the confusion due to my last post here, what I MEANT to say was
"are Class 12.9 Socket Head Cap Screws acceptable, and additionally what is the pitch of the diameter of the bolt and the pitch of the thread, I may know a source for all the bolts we want! :D , if the 12.9 is OK.
 

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markandson said:
Sorry for the confusion due to my last post here, what I MEANT to say was
"are Class 12.9 Socket Head Cap Screws acceptable, and additionally what is the pitch of the diameter of the bolt and the pitch of the thread, I may know a source for all the bolts we want! :D , if the 12.9 is OK.
Stock bolts are 12 x 1.5 pitch, with approximately 36mm of thread, the short bolts are +- 70mm long, the long bolts are +- 92mm long.

12.9 grade bolts are certainly up to the task. BUT, there are some potential pitfalls.

If overtorqued appreciably from stock specs, the 12.9 bolts would be up to the task, but the head and block would potentially distort. How much is tough to say, but I won't torque head bolts beyond 80-85 ft lbs. After that head gaskets tend to blow, which leads me to believe the added torque is distorting the area around the bolt threads, and essentially lifting the head from the deck surface.

On the other hand, if higher grade bolts are not torqued enough, the gasket can blow just as easily. There needs to be a certain degree of elastic stretch in the bolt 'as installed'. Otherwise the bolt strength is useless.

Rod bolts are an excellent example of this, if a high strength ARP bolt is installed with a measured .0055"-.006" of stretch, the bolt is substantially stronger than stock (this occurs at about 43 lb ft of torque for an Opel). If you torque the high strength bolt to the stock Opel spec of 36 lb ft, there is not enough stretch. What happens if under cycling of the connecting rod the bolt will stretch the additional amount needed, the rod cap pulls away from the rod, and either the rod bearing spins or the bolt breaks since it is now unsupported.

Head bolts won't break, but if they stretch under use the head gasket can push out. So if you use the 12.9 bolts you will need to 'guesstimate' the required torque spec to avoid each pitfall.

Bob
 

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kwilford said:
RallyBob, what do you make of all this? Is this OK, or just a waste of time. Or something in between? Please be honest, or at least provide a couple of perspectives on my comments above.
While I would have prefered OEM grade 10.9 bolts, I see no problems with using 9.8's for any basic rebuild or performance street engine. My 'order' still stands then.

The stock 10.9's have proven themselves to be capable of handling a 9500 rpm 200+ hp engine, or even 450+ hp turbo engines. I have had a few head gasket failures with the later 8.8's, but that was always from re-use of a 'throw-away' bolt that was not intended to be reused (like water cooled VW's and most Nissans).

So IMO, they're fine for 99% of the applications out there.

Bob
 

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Well, I guess that's the problem. The bolts I was looking at are 12.9, but the pitch is 1.75, the only 1.5 pitch bolts listed are hex head, not socket head.
Thought I had a winner but :( , NOT.
 

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Discussion Starter · #77 ·
markandson said:
Well, I guess that's the problem. The bolts I was looking at are 12.9, but the pitch is 1.75, the only 1.5 pitch bolts listed are hex head, not socket head.
Thought I had a winner but :( , NOT.
Yep, that's why I was kind of excited to find these, and 100 sets to boot! I am still waiting on a response from the vendor about cost; when I hear back, I will post the final total price in a new poll to solicit orders.
 

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why do I need them, again...

kwilford said:
I
although the OEM bolts can be used many times before they are susceptible to stretch.

I dont know if I need these. I got 3 questions...My spare engine is apart,soon we will be putting it back together

1- Keith says the stock bolts can be re-used...I dont plan on rebuilding the engine more than once..so why do I need new ones?

2- will the bolts fit easily or not? I thought I read that the hole needs tapped out due to longer depth.Will a washer cause new problems?

3- I have heard the tap can break as you go for depth, I would rather have used CIH OEM bolts than a broken tap in a hole.
thanks a buch
 

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1 are you sure your bolts are good to begin with?

2 You can easily cut a thread or 2 off for matching length.

3 A standard tap was used in the block so you can follow with a bottom cutting tap and gain more threads.
 

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Discussion Starter · #80 ·
RallyBob said:
...the short bolts are +- 70mm long, the long bolts are +- 92mm long.
Bob
Bob, am I correct in assuming that these new bolts will have to cut down for the 1.9 head? Do you think a washer will be required, or even sufficient without cutting the bolts down? I would just go and measure the length of thread in the block, but both my blocks and heads are tucked away right now. Thanks!
 
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