Headstuds & rod bolts

[Milo_101]

Finishing engine build on a AE86 turbo project I got going on.

7-rib 4ag block,Bluetop (Largeport) 16v head. just about to install 8.0 GZE pistons and rods.

SInce i'm opening the engine up, i'd like to install some ARP headstuds and rod bolts.
However I cannot find specific gze rod bolts. The headstuds I assume are the same as normal 4AGE 16v (?).

But are the rod bolts the same aswell? I found a set on ebay but it states 4ag 4alc, so I cannot know for sure. gze rod bolts cannot be same as regular N/A 16v bolts right?
I looked on summit but and found these: http://www.summitracing.com/parts/arp-2 ... plications

Those seem like the right ones. Anybody can confirm?

Also, What are my choices for headgasket. This engine will be boosted and abused, and I want something that can handle the abuse and possibly raise compression a bit too as 8.0 is pretty conservative. my 3sgte comes 8.5 stock. What are my options? Anybody have tried & true setps willing to share what you used?

Thanks!

[gotzoom?]

Any reason you wouldn't just use the bolts you have? The factory service manual has the measuring procedure. If they are in spec, there is no reason to replace them.

[jdm86gtz]

Use the 4AG rod bolts. The 4AGZE uses the same rods as a 4AGE of the same year.
With the headstuds you might need to shave the distributor shaft to clear the top of the first stud on the exhaust side.
You can either taper it until it clears or cut it short until it clears, this is not always a problem though.

[yoshimitsuspeed]

jdm86gtz got it all right.
I would definitely use ARP on the conrods. The rest depends more on the application and how hard you plan to push it.
http://matrixgarage.com/store/engine-internals

I can get HKS and cometic gaskets from .7mm and up.

[Milo_101]

Any reason you wouldn't just use the bolts you have? The factory service manual has the measuring procedure. If they are in spec, there is no reason to replace them.

The reason is that rod bolts are a somewhat common failure on 4ag engines and since i'm already opening the engine to install gze pistons, might as well go with some arp bolts.
This motor will see upwards of 15psi all the time when finished, so I want it to be as reliable as it can be. And this isn't overkill at all IMHO.

[Milo_101]

Use the 4AG rod bolts. The 4AGZE uses the same rods as a 4AGE of the same year.
With the headstuds you might need to shave the distributor shaft to clear the top of the first stud on the exhaust side.
You can either taper it until it clears or cut it short until it clears, this is not always a problem though.

Thanks for the info, Really appreciate it. will keep an eye out for that.

jdm86gtz got it all right.
I would definitely use ARP on the conrods. The rest depends more on the application and how hard you plan to push it.
http://matrixgarage.com/store/engine-internals

I can get HKS and cometic gaskets from .7mm and up.

Yes thank you. What price can you get those HG for?
What's the rule of thumb on 4AG's on compression ratio and headgasket. How much would .7mm raise compression for instance?
It's my first time building small displacement 4ag engine and I want to do it right. any info is greatly appreciated.

[yoshimitsuspeed]

I'll check on price a little later.
With a MLS HG especially one that thin you will want to deck the head and block so you will want to factor that. If you want more compression you can have them take a little more off.

Use a compression ratio calculator online and this info.
http://forums.club4ag.com/zerothread?id=55003
http://www.club4ag.com/faq_and_tech_pag ... ations.htm


Use the calculator to get your current compression ratio with your current setup and then play with HG thickness and deck height to see the effects of bringing it down.

[allencr]

1st
http://www.hachiroku.net/forums/showthread.php?t=32963
2nd
'rod bolts are a somewhat common failure on 4ag engines' You've never read that on this forum, please tell us where??
3rd
Sorry Y, I'd avoid ...............................

[Milo_101]

Thanks, I was searching for 4AG specific ARP hardware on google and I forgot to check one of my regular websites I use for parts for my SW20 Turbo.
www.twosrus.com

Found ARP rod bolts,main studs, head studs, for $54, $99, and $135 respectively.
They also have HKS metal headgasket for 135.

The F/S section here is pretty quiet so I doubt i'll find a better price for these new stuff on the forums.

[yoshimitsuspeed]

You will see the same prices for all those things on my website.
Twosrus only sells the 1.6mm and 2mm headgaskets. Those are both thicker than stock.
I just emailed my distributor to make sure I can get the thinner gaskets.

[yoshimitsuspeed]

I just heard back from my distributor and it sounds like the thinner HKS HGs are discontinued so if you want a thinner than stock it looks like Cometic is the way to go. I can do one for $95

I believe the TRD gasket is still available but I don't know since I don't carry it.

[Milo_101]

I just heard back from my distributor and it sounds like the thinner HKS HGs are discontinued so if you want a thinner than stock it looks like Cometic is the way to go. I can do one for $95

I believe the TRD gasket is still available but I don't know since I don't carry it.

Allright thanks alot, I appreciate the help.
I'll do some more reading and when I make my decision i'll let you know.
Should I do ARP main studs aswell? or are the stock ones able to handle it? I'm surely doing to head studs and rod bolts, just want to know if replacing main studs are worth it while i'm in there.

You're name is kinda familiar, Are you on mr2oc by an chance?

[yoshimitsuspeed]

Yeah, I'm on the MR2OC and MR2board. The OC is where I spend my time for fun and where I go looking for most of my technical information.

I would do main studs on a motor before I did head studs.
Now whether or not they are necessary depends on your build and use.
For a high reving motor and or for extremely high boost they will be much more important. For your average motor they probably won't make a difference but there will be that little bit of added margin for error that could prevent the off chance failure.
There is also the better chance that you will be able to reuse them in the future.
If you are doing an all out build and really pushing things, I can get Tomei ladder caps