pulled studs on 2.0-2.4?

Tim Walsh · Tim Walsh's Garage

I was speaking with my wrench yesterday and he had some interesting things to say when it comes to rebuilding engines. Evidently he never puts casesavers or timeserts in his 2.0-2.4L engines and hasn't had a single one come back with pulled studs in 30 years. This seems really wild but I wanted to see How many people out there have personally seen or had (not heard about) pulled studs on a 2.0-2.4L stock engine.

PS I'm definitly puting inserts into my case.

Anybody?

yelcab1 · 11-13-2003, 07:27 AM

it is the 2.7L and 3.0L engines that are known for pulled studs. The smaller engine don't generate enough heat to be a problem.

Having said that, installing case savers in an aluminum case is always a good idea if you have it apart and can afford the extra costs.

tobluforu · tobluforu's Garage

72 2.4 with rs p\c's. I have the stock studs still in there. They must have close to 150,00 on them now (Hard).

rvanderpyl · rvanderpyl's Garage

2.0-2.4 didn't pull studs because they didn't use Nikasil cylinders, they used cast iron, either completely cast iron for the T's or a cast iron cylinder with aluminum fins on E/S, Since these cylinders had nearly the same expansion ratio as the steel studs you don't have pulling problems. The Nikasil cylinders used on the 2.7 and above have a much higher rate of expansion than the studs, hence the pulling. So if you rebuild and continue to use original cylinders you don't need inserts, if you replace your cylinders with Nikasil because you are increasing your displacement you need to add inserts.

HarryD · 11-13-2003, 10:12 AM

We looked at the head studs when I had my top-end done at 118,000 miles. No issues in my 2.4L CIS.

jim72911t · 11-13-2003, 10:41 AM

Good timing on the post. I just had this conversation yesterday with my machinist. He says he generally doesn't see problems with the early mag case motors. However since my motor has 133,000 miles on it, and should see a bit of track use, I'm putting inserts in mine. Heck, it's apart, it's at the machine shop, and it's not much money for the peace of mind.

BTW, everything else checked out fine, including crank, line bore, etc.

Jim
'72T, soon to be high comp E spec MFI

MFAFF · 11-13-2003, 10:44 AM

Never heard of pulled studs on the 'small' 911 engines (2.0 to 2.4ltr), becasue they didn't have the differential expansion issue.
But them I've never heard of pulled studs on the RS 2.7 engine either (73 and 74RS BTW). That was the first to use the Nikasil cylinders

Is this problem not more linked to engines which has the 'thermal' reactors as well?

I seem to recall reading that these increased the engine temps quite noticeably and therefore increased the differential expansion problem.