924Board.org

HappyPuppy · Guest

Hey guys, I'm finally reassembling my poor 924's engine, and I want to make sure I get it right the first time.

Do I need to go out and buy a head stud kit, or will my old head bolts do?

Where can I pick up the bolts for the oil pan, crankshaft center bolt, and pulley bolts?

Do I have to disassemble the valvetrain to port and polish my intake and exhaust ports? The valves have already been lapped.

Any other tips you guys might have would be greatly appreciated.

cya

924RACR · Posted: Fri Dec 07, 2001 2:30 am Post subject:

I've reused the bolts, including head, crank pulley, etc.

Depends a little on exactly what you have in mind, but I expect you will have to disassemble the valvetrain and remove the valves in order to gain access to the ports enough to do any work.

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

HappyPuppy · Guest

Well, the crank pulley bolts are pretty gone, so I'll be needing new ones.

Also, is the FelPro head gasket AA sells good enough for the 924? I'm only asking b/c it's like 30 bucks.

cya

924RACR · Posted: Fri Dec 07, 2001 7:20 am Post subject:

If you haven't already got all your components, you can get them from Engine Builder's Supply in Sparks, NV (www.ebsracing.com) - good stuff, good prices, and very knowledgable. Can't remember how my last Fel-Pro head gasket went, but it's probably OK. Anyone disagree? Usually I end up w/ Elring or Victor Reinz gaskets.

As for the crank pulley bolts - not surprised they went, they don't usually survive disassembly. Of course, they don't usually need to be disassembled, just the one big 24mm bolt to remove the pulley itself from the crank. They should be replaceable from the bolts bin at a decent local hardware store - just make sure to replace with the same head type, since a standard hex head won't fit inside the pulley, I don't think. Lowe's actually usually has a very good selection of high-grade metric and SAE bolts and nuts...

Good luck! Feel free to post back with any other questions...

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

HappyPuppy · Guest

what about finding new oil pan bolts? A couple of those went as well.

cya

924RACR · Posted: Sat Dec 08, 2001 4:05 am Post subject:

I would suggest same as with the crank pulley bolts, try a good hardware store...

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

HappyPuppy · Guest

Not to sound disrespectful, but would a hardware store really carry those weird bolts? I was thinking maybe bike shop, since they're that funky inset hex wrench type.

BTW, cheapest I've seen rod and main bearings are $45 for either. Do they go for less?

cya

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

just make very sure that when you're saving money on those bolts and other parts you don't put your safety or the engine at risk.

Remember, the engineers used bolts and parts of a particular specification for a reason and like all engineers they probably had the suits demanding that they justify every single bolt.

The last thing you want is to have your engine do a "BANG, chunka, chunka, chunka" just because you saved $50 by using cheap fastenings or worse, have your flywheel try and saw it's way into the footwell at 8000rpm

HappyPuppy · Guest

Don't get me wrong--I love my 924, probably against common sense. I'm just trying to find the cheapest price for quality parts, not the cheapest parts. I want to make my 924 run forever!

So, where do find those weird oil pan bolts?

cya

larso · Guest

Yeah the oil pan bolts you might find at a bike store, bikes have a lot of allen bolts on them.. I think I still have oil pan bolts from my old oil pan, how many and which ones do you need? Or are you looking at only new ones for some other reason.

larso · Guest

Also, if you can find it on the bolt head, it usually has a number on it such as 8.8. If it is anything higher than the standard 8.8, it's going to be expensive from a specialized nut and bolt store. I can't remember if allen bolts have the same standard 8.8 as the hex bolts do.

Things like shocks and suspension parts sometimes have higher ratings. You probably don't have to worry with oil pan bolts, but engine and head bolts will most likely be special strengths and materials.

HappyPuppy · Guest

I really don't know how many I need yet, but I'd be willing to buy them all from you. My oil pan bolts look to be mostly missing and pretty torn up.

cya

Rick MacLaren · Guest

I took mine to have the rods balanced and pistons and crank balanced. I'm replacing the rod bolts on mine, all the bolts holding in the crank, and any other bolts I find.

I would replace the head bolts without question! WHY CHEAP OUT on an engine job?

The book "Super Power" outlines the sort of basic replacements for a good rebuild. I can provide you the ISBN if you're interested.

_________________
1980 Porsche 931 Bitched.
1979 Porsche 924 Tweaked.

[ This Message was edited by: Rick MacLaren on 2001-12-13 04:04 ]

HappyPuppy · Guest

Rick, I'm not cheaping out--I simply don't have the money to go out and replace everything with new parts. I will agree that head bolts are a good idea to replace, but the crankshaft bearing bolts look fine.

Sadly I now have a more important question. I accidentely knocked my cylinder head off the shelf it was on. It tumbled, hit the top rail on my bicycle, then tumbled more and hit my carpeted wooden floor. I put it on my block without the head gasket, to check for clearances, and I see a little sliver of daylight between the two.

Though I really doubt it, is this normal? If not, can it be milled down? By how much? Thanks guys

cya

John H · Guest

The head (on the 931) can be machened down to provide a level surface. On the 931 head on the rear inlet side of the head at the back there is a hole just below where the tappet cover bolts to. The distance from the bottom of this hole to the under side of the head should be at least 139.55mm. If it's less than this then the head is throwaway material.
I assume there is similar sor tor measurements on the non turbo head. Chances are if the head hasn't been milled before you can remove the bow you seem to have.