got any head bolts you can part with?

[Parzival]

I'm close to putting my heads back on, I bought some head bolts from Delorean go, but have now been informed that they are wrong, and will result in eventual failure of the head gasket. Huston is out of head bolts, and Delorean Industries is out until they produce another run, which may be soon, but not sure.
So if anyone out there has a NOS set of head bolts laying around, I'd be happy to take them off your hands.

[Giamanut]

I'm close to putting my heads back on, I bought some head bolts from Delorean go, but have now been informed that they are wrong, and will result in eventual failure of the head gasket. Huston is out of head bolts, and Delorean Industries is out until they produce another run, which may be soon, but not sure.
So if anyone out there has a NOS set of head bolts laying around, I'd be happy to take them off your hands.

Wow how did they send you the wrong bolts? I got mine about a week ago from Houston!

[Giamanut]

Wow how did they send you the wrong bolts? I got mine about a week ago from Houston!
https://www.volvopartswebstore.com/showAssembly.aspx?ukey_assembly=236003&ukey_make=865&ukey_model=20829&modelYear=1984&ukey_category=7072&ukey_driveLine=417&ukey_trimLevel=28245

[Parzival]

Wow how did they send you the wrong bolts? I got mine about a week ago from Houston!

Its not that they are wrong, its what they sell. According to some advice I got from an experienced Delorean tech, they are not rated high enough for use in the PRV. The are bolts for a chevy, and they do fit, but apparently will stretch and cause the a head gasket leak. I tried to get some NOS bolts from huston but they only had 12 left in stock, and mixing and matching head bolts seems like a bad idea so I passed on them.

[Ron]

Its not that they are wrong, its what they sell. According to some advice I got from an experienced Delorean tech, they are not rated high enough for use in the PRV. The are bolts for a chevy, and they do fit, but apparently will stretch and cause the a head gasket leak. I tried to get some NOS bolts from huston but they only had 12 left in stock, and mixing and matching head bolts seems like a bad idea so I passed on them.I find it hard to believe that Chevy bolts are not rated high enough. But that be the case, call Summit (https://www.summitracing.com/search/part-type/cylinder-head-fasteners?sortby=Default&sortorder=Ascending&N=part-type%3acylinder-head-fasteners&keyword=head+bolts&kr=head+bolts) they have Chromoly, Cadmium....

[Bitsyncmaster]

What do the rating numbers on the heads of the bolts say?

[Giamanut]

Its not that they are wrong, its what they sell. According to some advice I got from an experienced Delorean tech, they are not rated high enough for use in the PRV. The are bolts for a chevy, and they do fit, but apparently will stretch and cause the a head gasket leak. I tried to get some NOS bolts from huston but they only had 12 left in stock, and mixing and matching head bolts seems like a bad idea so I passed on them.

What chevy ? and prv bolts also stretch did you check the link I posted they are item number 44 in the diagram.
Funny thing is that each cylinder makes about 22 HP I think DeloreanGo head bolts are fine. My experience with them is they don't sell junk. And I am sure they are class 10.9 tty bolts. I got mine from Houston and some of them had surface rust. 50 year old bolts NOS or not, are not necessarily a great choice either!

[Parzival]

I totally agree that DeloreanGo is a good vender, I've spent tons of money with them. I'm just getting worried about the info I got about these head bolts.

The exact criticism I got about these bolts.

Quote Below
"You posted a picture of aftermarket bolts in one of your posts. Is this what you intent to use or just posting as reference? Unfortunately the Ajusa bolts are wrong for this application for a number of reasons.

The threads are roll formed onto the OD of the bolt- This results in a depth contact issue on the aluminum block threads while torque procedures are performed. You will have serious problems with getting gaskets to seat due to this.

The bolt is below a nominal specification for use- If you look at the head of the bolt it is stamped 8.8. This gives it a Grade 8 rating. The factory fasteners are 10.9 which by comparison and taking the rockwell rating of 28 on the grade 8 versus the 40 on the 10.9 is nearly a 70,000 psi difference. End result is the bolt will stretch and loose tension resulting in head gasket leaks. I would strongly recommend investing in factory style bolts and or head studs."

I know different vendors have differing opinions, as a mere DIYer I don't have the experience to know, and have to listen to all the advice I get, and weigh the differences out my self.
I bought these from DeloreanGo based on the assumption that they sell parts that work. I was all set to use these bolts, but then I got the above advice.
I just want the car to work, for preferably a long time.

[ed uding]

We use the ajusa bold for years with turbo and blower setups. Never fail, rock solid and if you tight it up right, the are perfect.
I rebuild every year lots of stock engine's, and special projects. There not one sign tht the bold are weak or bad. 100% first hand.

Ed Uding
www.delorean.eu


I totally agree that DeloreanGo is a good vender, I've spent tons of money with them. I'm just getting worried about the info I got about these head bolts.




The exact criticism I got about these bolts.

Quote Below
"You posted a picture of aftermarket bolts in one of your posts. Is this what you intent to use or just posting as reference? Unfortunately the Ajusa bolts are wrong for this application for a number of reasons.

The threads are roll formed onto the OD of the bolt- This results in a depth contact issue on the aluminum block threads while torque procedures are performed. You will have serious problems with getting gaskets to seat due to this.

The bolt is below a nominal specification for use- If you look at the head of the bolt it is stamped 8.8. This gives it a Grade 8 rating. The factory fasteners are 10.9 which by comparison and taking the rockwell rating of 28 on the grade 8 versus the 40 on the 10.9 is nearly a 70,000 psi difference. End result is the bolt will stretch and loose tension resulting in head gasket leaks. I would strongly recommend investing in factory style bolts and or head studs."

I know different vendors have differing opinions, as a mere DIYer I don't have the experience to know, and have to listen to all the advice I get, and weigh the differences out my self.
I bought these from DeloreanGo based on the assumption that they sell parts that work. I was all set to use these bolts, but then I got the above advice.
I just want the car to work, for preferably a long time.

[Parzival]

We use the ajusa bold for years with turbo and blower setups. Never fail, rock solid and if you tight it up right, the are perfect.
I rebuild every year lots of stock engine's, and special projects. There not one sign tht the bold are weak or bad. 100% first hand.

Ed Uding
www.delorean.eu

Thank you!


Sent from my iPhone using Tapatalk

[Parzival]

We use the ajusa bold for years with turbo and blower setups. Never fail, rock solid and if you tight it up right, the are perfect.
I rebuild every year lots of stock engine's, and special projects. There not one sign tht the bold are weak or bad. 100% first hand.

Ed Uding
www.delorean.eu

What torque values do you use?

[Ron]

If you are using factory head gaskets use factory torque specs. Otherwise, the procedure/torque may be different, so call the vendor (E.G., I've used several of DPI's and they were one pass, no re-torque. No problems!)

[ed uding]

20 nm first
60 nm wait 30 min
All back to 20 nm
And turn it 115%
Ready

[Ron]

Double check with ED, but I think he meant:
20 nm first
60 nm wait 30 min
One at a time, back to 20 nm
And turn it 115° (not "%")
Ready

(Like the Manual)

===========

Since I'm on a roll, FWIW-
An ISO 8.8 and a SAE Grade 5 ( Not 8 ) are almost equal (120,350 v/s 120,000 psi).
An ISO 10.9 and a SAE Grade 8 are almost equal (150,850 v/s 150,000 psi).
The difference is: 150,850 - 120,350 = 30,500 psi, or 30,500/1250,350 * 100 = 20.2%

:dunno:

[Ethan Rode]

I used the AJUSA bolts on a stock motor using Reinz head gaskets. No problems after about 2500 miles. I used factory specs.

[Parzival]

I used the AJUSA bolts on a stock motor using Reinz head gaskets. No problems after about 2500 miles. I used factory specs.

Good news, I have the reinz head gaskets too. I went ahead and ordered some head bolts from volvo. Looks like I have a set of Ajusa if anyone needs them.

[Parzival]

https://www.volvopartswebstore.com/showAssembly.aspx?ukey_assembly=236003&ukey_make=865&ukey_model=20829&modelYear=1984&ukey_category=7072&ukey_driveLine=417&ukey_trimLevel=28245

Yep, I went ahead and ordered them.

[Ron]

Cool! (I'm glad Giamanut bird-dogged the universal (aka "comfortable") solution ;-)
:wrenchin:

[Parzival]

Scratch that, the volvo site emailed me to say they don't actually have the bolts.

[Ron]

Have you called DMCMW?

[Parzival]

Have you called DMCMW?

Yes, Mike doesn't have any. He also recommended against using bolts rated less then the factory 10.7

[Giamanut]

Yep, I went ahead and ordered them.

Good for you! Hope everything works out great!
I am loving the way mine is running if it wasn't wet out I would go for a spin!

[Giamanut]

Scratch that, the volvo site emailed me to say they don't actually have the bolts.
oops really? dam. sorry to hear that!

[Parzival]

oops really? dam. sorry to hear that!

Yep, I’m still on the hunt


Sent from my iPhone using Tapatalk

[Giamanut]

Yep, I’m still on the hunt


Sent from my iPhone using Tapatalk

Well I did find these! https://deloreanindustries.com/8-head-stud-kit-complete-performance/ 395 but you don't have to worry about them at all!

[David T]

Have you tried ARP?

[Giamanut]

Have you tried ARP?

I have could not find anything. Not sure who makes the one that DI sells but they look like arp

[Parzival]

NOS head bolts acquired. The last ones around

[Giamanut]

NOS head bolts acquired. The last ones around

Bet some guy has a whole barrel full of them and does not even know it! :8ball:

[Parzival]

Bet some guy has a whole barrel full of them and does not even know it! :8ball:

yep, just rusting away,
Could have made a few hundred bucks if he had a set up for sale

[Nicholas R]

I totally agree that DeloreanGo is a good vender, I've spent tons of money with them. I'm just getting worried about the info I got about these head bolts.

The exact criticism I got about these bolts.

Quote Below
"You posted a picture of aftermarket bolts in one of your posts. Is this what you intent to use or just posting as reference? Unfortunately the Ajusa bolts are wrong for this application for a number of reasons.

The threads are roll formed onto the OD of the bolt- This results in a depth contact issue on the aluminum block threads while torque procedures are performed. You will have serious problems with getting gaskets to seat due to this.

The bolt is below a nominal specification for use- If you look at the head of the bolt it is stamped 8.8. This gives it a Grade 8 rating. The factory fasteners are 10.9 which by comparison and taking the rockwell rating of 28 on the grade 8 versus the 40 on the 10.9 is nearly a 70,000 psi difference. End result is the bolt will stretch and loose tension resulting in head gasket leaks. I would strongly recommend investing in factory style bolts and or head studs."

I know different vendors have differing opinions, as a mere DIYer I don't have the experience to know, and have to listen to all the advice I get, and weigh the differences out my self.
I bought these from DeloreanGo based on the assumption that they sell parts that work. I was all set to use these bolts, but then I got the above advice.
I just want the car to work, for preferably a long time.

Whoever told you this is confusing various topics in bolt classification. I'm not quite sure what they're trying to say about bolts being stamped 8.8 therefore being grade 8 as they're mixing the SAE and Metric ratings in a way that doesn't exist.

Metric ratings are by classes: 8.8, 10.9, 12.9.
SAE ratings are by grade: 2, 5, 8.

There is not a direct equivalency between the two rating types as they're governed by completely different industry standards. It can be said that class 8.8 is close to grade 5, and class 10.9 is close to grade 8, but there isn't a direct relationship. There can also be different requirements depending on the diameter.

The note about the strength difference between 8.8 and 10.9 being 70KSI is also wrong. The difference is closer to 30,000PSI. In general, when dealing with metric hardware, the pre-decimal number in the grade refers to the minimum tensile strength of the bolt in MPa.
Class 8.8 ~ 800MPa = 116,000PSI
Class 10.9 ~ 1000MPa = 145,000PSI
Class 12.9 ~ 1200MPa = 174,000PSI

[Josh]

I totally agree that DeloreanGo is a good vender, I've spent tons of money with them. I'm just getting worried about the info I got about these head bolts.

The exact criticism I got about these bolts.

Quote Below
"You posted a picture of aftermarket bolts in one of your posts. Is this what you intent to use or just posting as reference? Unfortunately the Ajusa bolts are wrong for this application for a number of reasons.

The threads are roll formed onto the OD of the bolt- This results in a depth contact issue on the aluminum block threads while torque procedures are performed. You will have serious problems with getting gaskets to seat due to this.

The bolt is below a nominal specification for use- If you look at the head of the bolt it is stamped 8.8. This gives it a Grade 8 rating. The factory fasteners are 10.9 which by comparison and taking the rockwell rating of 28 on the grade 8 versus the 40 on the 10.9 is nearly a 70,000 psi difference. End result is the bolt will stretch and loose tension resulting in head gasket leaks. I would strongly recommend investing in factory style bolts and or head studs."

I know different vendors have differing opinions, as a mere DIYer I don't have the experience to know, and have to listen to all the advice I get, and weigh the differences out my self.
I bought these from DeloreanGo based on the assumption that they sell parts that work. I was all set to use these bolts, but then I got the above advice.
I just want the car to work, for preferably a long time.

As Nick said, there is a lot of wrong information in this "advice" you were given.

[Ron]

Whoever told you this is confusing various topics in bolt classification. I'm not quite sure what they're trying to say about bolts being stamped 8.8 therefore being grade 8 as they're mixing the SAE and Metric ratings in a way that doesn't exist.

Metric ratings are by classes: 8.8, 10.9, 12.9.
SAE ratings are by grade: 2, 5, 8.

There is not a direct equivalency between the two rating types as they're governed by completely different industry standards. It can be said that class 8.8 is close to grade 5, and class 10.9 is close to grade 8, but there isn't a direct relationship. There can also be different requirements depending on the diameter.

The note about the strength difference between 8.8 and 10.9 being 70KSI is also wrong. The difference is closer to 30,000PSI. In general, when dealing with metric hardware, the pre-decimal number in the grade refers to the minimum tensile strength of the bolt in MPa.
Class 8.8 ~ 800MPa = 116,000PSI
Class 10.9 ~ 1000MPa = 145,000PSI
Class 12.9 ~ 1200MPa = 174,000PSI+1

A bit more on the identifications:
SAE
Add 2 to the number of marks to get the grade.
EX: 0 marks => Grade 2, 3 marks = Grade 5, etc.

METRIC
X.Y
X = Minimum Tensile Strength; Add 2 Zeros for MPa.
Y = Approximate Yield Strength Percentage of X, Add 1 Zero for percentage of X KPa.
EX.: 10.9 => 1000MPa, 90% of 1000 = 900MPa Appx. Yield Strength percentage.

X Varies from chart to chart, because it is a range (EX. 1000-1040 KPa) where some show the minimum or maximum, others average... (What's 4.0% among friends, eh? ;-)

======

I can't blame Parzival for holding out for OEM bolts, not having a lot of experience using Chevy bolts. Like Ed, and others, I've used 100's of them. I currently have a 2500 Chevy truck with a 5.7L. It has flattops, milled heads, wild cam, etc., and a Whipple Super Charger on top. ~150K (hard miles ;-) using stock Chevy bolts w/o any problems. So before all of this, I would probably have used the AJUSA bolts on my own D, not finding OEM. But on a customer's D, knowing the difference, absolutely not. 20% off OEM spec is not going to bite me!
I've put at least 2 sets in D's running around right now with customer supplied parts -- Not a whole lot of mileage on them yet...time will tell.

[Giamanut]

+1

A bit more on the identifications:
SAE
Add 2 to the number of marks to get the grade.
EX: 0 marks => Grade 2, 3 marks = Grade 5, etc.

METRIC
X.Y
X = Minimum Tensile Strength; Add 2 Zeros for MPa.
Y = Approximate Yield Strength Percentage of X, Add 1 Zero for percentage of X KPa.
EX.: 10.9 => 1000MPa, 90% of 1000 = 900MPa Appx. Yield Strength percentage.

X Varies from chart to chart, because it is a range (EX. 1000-1040 KPa) where some show the minimum or maximum, others average... (What's 4.0% among friends, eh? ;-)

======

I can't blame Parzival for holding out for OEM bolts, not having a lot of experience using Chevy bolts. Like Ed, and others, I've used 100's of them. I currently have a 2500 Chevy truck with a 5.7L. It has flattops, milled heads, wild cam, etc., and a Whipple Super Charger on top. ~150K (hard miles ;-) using stock Chevy bolts w/o any problems. So before all of this, I would probably have used the AJUSA bolts on my own D, not finding OEM. But on a customer's D, knowing the difference, absolutely not. 20% off OEM spec is not going to bite me!
I've put at least 2 sets in D's running around right now with customer supplied parts -- Not a whole lot of mileage on them yet...time will tell.
I would use chevy head bolts which ones work?

[Parzival]

I would use chevy head bolts which ones work?

Well The bolts I bought from delorean go I believe are made for a Chevy Citroen. They are stamped 8.8 on the heads. Those are the ones I've opted not to use in favor of the NOS head bolts.

Looks like I have some reading to do to catch up on what all that means.

[Rich_NYS]

So.....what bolts are OK to use?

[DeLoreanGo Arran]

Just to try and clear up some inaccuracies in this post..... The bolts that we sell (and Ed at DeLorean Europe sells) are proper cylinder head bolts, made by one of the best, if not the best, cylinder head bolt manufacturers in Europe (Ajusa). They are not bolts bought from a hardware store. They are Ajusa's reference for the DeLorean engine, and have a number of other manufacturer's engine types written on the outside, of which Chevy is NOT one of them.... Some of the manufacturers mentioned include Chrysler, Dodge, Citroen, amongst others - these are just other cars that use the same length of bolt. This is in the much the same way as brake pads list a number of other cars on the box.
They are designed to stretch, and they are designed to be used just once - same as the originals. These are metric class 8.8, and correctly matched to the torque specifications and heat of the DeLorean cylinder head.
Using incorrect grades of bolt could lead to overtorquing, which could lead to head damage. Has anyone looked at the stamps on an (actual) original bolt...?

[Parzival]

So.....what bolts are OK to use?

Well, depends who you talk to.
I bought the bolts from deloreango that are 8.8. have the correct thread pitch and length, and are made by a good company.
However the bolts the engine was built with are 10.9 I had several people email me telling me to not use the ones from delorean go. I posted the exact reasons I was told (these were not my criticisms, just what I was told) I have had another person tell me that they used the bolts from Delorean go and they were working great, however the person has only gone 2500 miles on them.

So being someone without much experience what can I do, one guy says one thing and another something else! I like DeloreanGo, they have good service. I also like some of the people who have told me those bolts are wrong for this application.

The ONLY THING I can truthfully testify to first hand (everything else is coming to me third party) is that the bolts that were in there originally are stamped 10.9
So with that being the only evidence I can smell, touch, taste, or see. I sourced some NOS bolts that are also 10.9

I'm trying to do this work with as much diligence as I can, I even ordered every brand of head gasket to compare them at my own expense 4 different sets. (with no plans to return the ones I'm not using) so far I'm leaning to the reinz head gaskets to put on the car.
Perhaps I'll make a video showing all 4 sets comparing them.

[Ron]

I would use chevy head bolts which ones work?
Ones with a 10.9 on them... :neener:


Has anyone looked at the stamps on an (actual) original bolt...?I have 5 sets in a box and they all look like this:

61829


==============

I believe, but am not 100% sure, that a 1982 Volvo 264 GLE 2.8 V6 B28F uses the same head bolt. If so, it comes up as an "Original Mahle bolt Part No. GS33539", which is on national back order according to Volvo.
Supposedly, it will be available Dec 16.

I have a question- Thinking back about Chevy's in the 80's, usually, you could reuse the head bolts. So, I looked in several DeLorean, Volvo, etc. manuals. Most say clean and lubricate the head bolts. Only one mentioned replacement:
"PARTS TO BE RENEWED WHENEVER THEY ARE REMOVED.
...
cylinder head bolts (if using an asbestos-free gasket)".
What's up with that?

[Parzival]

...[/I]
cylinder head bolts (if using an asbestos-free gasket)".
What's up with that?

Asbestos is a better material then what is used in gaskets now. It has stopped being using for health reasons, but nothing better has been developed. In fact asbestos was not a material developed at all, it is rather a naturally occurring material. It is one of the most indestructible yet flexible materials in existence. My guess as to why it makes a difference here is that the gasket made with asbestos will not yield in thickness no mater how many heat cycles it goes through, while a lesser gasket might. That little bit of extra give may come into play and effect a pre stretched bolts ability to hole the proper clamping force. This is just an idea as to why. Also the amount of asbestos in gaskets will vary brand to brand. It wont be 100% asbestos, and the asbestos that is in it will be highly refined fibers each around 100th the with of a human hair that are pressed with binders and other materials to create the paper like gasket materials.
The reason I know this is because I worked at the Kennedy Space center doing asbestos analysis for a few years. I have collected a number of samples from my car, and plan to do a full analysis on the various asbestos containing parts, heat shields, gaskets, etc etc.
If I could source NOS asbestos gaskets, thats what I would use where possible, its great stuff (if you're not grinding it up in a factory, or on a job site some where)
Some people even believe that discontinued use of asbestos at Morton Thiokol was the cause for the failure of the Challenger Space Shuttle in 1986, the o-rings that failed that day originally contained asbestos, but were later required to eliminate the use of it. That all far predates my time with the space program, in fact the shuttle program was gone before I ever started there, but many of the people that were around then believe that.

[Ron]

That's interesting... I've seen gaskets made of copper and it didn't matter. Weird!

[David T]

The use of copper was very common on older gaskets usually as rings around the holes that coolant passed through the gasket. Copper is also used as a sealing ring on engines with very high compression around the combustion chamber. The new composite gaskets are part of the system designed to seal the heads to the block. The clamping forces from the head bolts, the compression of the gasket, the pressures inside the combustion chamber, the heating, cooling, expansion and stretch of the bolts is all calculated and tested experimentally till it is all correct. In the PRV the clamping forces must also prevent the liners from moving and maintain a proper seal between the liners, the head and the block. The tensile strength of the bolts, the pull-out forces on the threads in the aluminum, all of this must be just so. That is why it is so important to assemble the engine according to the Workshop Manual using the recommended parts. The W/M does NOT say the head bolts can't be reused. Because it does not say that, one can assume the bolts are not torqued-to-yield. On some motors (not the PRV) the bolts are tightened so much that they stretch and cannot be reused. On some (not the PRV) motors you can actually measure the diameter of the bolts and if they have been used and stretched they are to be thrown away. The procedure for tightening the bolts is also important so that you get and maintain the correct clamping forces which is indirectly measured by the torque of the bolts. On the PRV there really is no good reason to replace the bolts unless they have been damaged or lost. As for the gaskets, asbestos hasn't been used since the 70's in the US. I don't know when it was stopped in Europe but they could have used it till much later. The original heat shields around the exhaust in the Delorean are asbestos! Asbestos is a common mineral and was used for many years in brakes and gaskets and fire-proofing. It was cheap and plentiful and is excellent at absorbing heat. Unfortunately the tiny fibers, once airborne, can cause lung cancer if inhaled. Modern replacements are getting better all the time and are now equivalent to asbestos but are expensive. Asbestos used to be sprayed all over the steel inside buildings to protect it in case of fire. Not anymore! On 9/11, when the towers went down, tons of asbestos went airborne contributing to many of the cancers that later developed. Every time a steampipe in NYC bursts, they have to decontaminate the area because of the asbestos that was wrapped around those old pipes underground in the streets.

[Parzival]

asbestos hasn't been used since the 70's in the US. I don't know when it was stopped in Europe but they could have used it till much later. The original heat shields around the exhaust in the Delorean are asbestos! Asbestos is a common mineral and was used for many years in brakes and gaskets and fire-proofing. It was cheap and plentiful and is excellent at absorbing heat. Unfortunately the tiny fibers, once airborne, can cause lung cancer if inhaled. Modern replacements are getting better all the time and are now equivalent to asbestos but are expensive. Asbestos used to be sprayed all over the steel inside buildings to protect it in case of fire. Not anymore! On 9/11, when the towers went down, tons of asbestos went airborne contributing to many of the cancers that later developed. Every time a steampipe in NYC bursts, they have to decontaminate the area because of the asbestos that was wrapped around those old pipes underground in the streets.

Thermal systems insulation or (TSI) is the most dangerous asbestos containing materials. That's what is on those steam pipes (its class 1) it has high concentrations of asbestos, and its easily crushed or pulverized (the term used is "Friable") Asbestos used in vinyl floor tiles for instance is far less dangerous as there is basically no way for the asbestos fibers to be freed (short of grinding it up with an angle grinder or something)

I lived asbestos everyday, and held every certification the EPA ever dreamed up as far as asbestos goes. Largely I worked as an analytical microscopist, I actually had to look at asbestos everyday, and even count fibers per square micron. Its an amazing material for everything but breathing.