Page 1 of 1

Studs vs. Bolts?

Posted: Fri Aug 23, 2019 7:38 am
by It's Bill
Hello, I have been reading up on heads and engine assembly, and came across a post that said every few years the head should be removed to clean out carbon from the combustion chamber. This is said to lead to wear on the block threads from removing and replacing the head bolts repeatedly. Does anyone use studs and nuts to fasten the head, or is this bad practice? When the block threads are finally shot, are helicoils the answer? When rebuilding an engine, is it good practice to install helicoils and be done with it?

Thanks for any advice, Bill

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 9:16 am
by Scott_Conger
Fuel and oil are so superior today that removing the head to remove carbon is not necessary. Studs are great, and superior, mechanically, to bolts. However, just try to remove the head when it's trapped on it's stud at the rear of the engine, though. You either have to pull the engine forward or raise the body to remove the head from over the stud.

If the engine is running OK, leave it alone.

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 9:59 am
by Humblej
I agree with Scott, for many Ts the firewall overhangs the rear of the engine and there is no room to lift the head over the rear stud. The model A engine has studs instead of head bolts. I can tell you from personal experience, removing a head under normal circumstances is a chore, with rusty studs it is a nightmare requiring heat, wedges, hammer, and a lot of cuss words.

Helicoils are a great fix for a stripped block, but makes no sense to fix something that isnt broke.

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 10:43 am
by RGould1910
Really hard to get the studs to line up exactly with the holes in the block. Remember there are 15 to get aligned and they are a close fit. Sometimes its hard to get even the six studs aligned on an early DS spool. 15 would be a nightmare.

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 10:44 am
by RGould1910
Really hard to get the studs to line up exactly with the holes in the block. Remember there are 15 to get aligned and they are a close fit. Sometimes its hard to get even the six studs aligned on an early DS spool. 15 would be a nightmare.

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 8:10 pm
by walber
Concern about clearance of the head vs. firewall is real. I've only used bolts on stock T's but with the Fronty on my speedster I went with studs. No issues and sadly have had to remove the head a couple times over the years. I put anti-seize on the studs when they are installed and when I need to pull the head, I first remove the studs and eliminate any binding problems. I don't happen to have a specific purpose stud puller so simply double nut the studs and they come out easily. You could do the same with a stock head but it obviously won't be correct (if that matters to you).

Re: Studs vs. Bolts?

Posted: Fri Aug 23, 2019 9:42 pm
by modernbeat
I'm building an Express body for my '26, with a flat firewall. So no overhang to trap the head on the rear studs. And a hotted up engine.
After cleaning the threads and measuring the depth of the holes in the block, the head gasket thickness, the Prus head thickness, and the nuts and washers I want to use, I'll be using Milodon 81255 4.25" studs. They are 7/16-14 thread at the bottom and 7/16-20 at the top. I'll be gluing them into the block with some Indian Head gasket shellac. This allows full thread engagement with the block, and the fine thread nut on the top allows a slightly tighter torque, and an easier torque process.

Re: Studs vs. Bolts?

Posted: Sat Aug 24, 2019 12:10 pm
by walber
Jason,

Just curious, why glue them in?

Walt

Re: Studs vs. Bolts?

Posted: Sat Aug 24, 2019 3:24 pm
by SurfCityGene
That'll work fine but like was mentioned before you'll have a real fun time getting it off maybe with the studs. Yes you will get a bit more squeeze on that gasket. Some guy I know prefer studs if they don't have a firewall issue. I don't think its needed with proper length bolts and our high compression heads.
YMMV

Re: Studs vs. Bolts?

Posted: Sat Aug 24, 2019 11:59 pm
by modernbeat
I know all the issues that studs bring. Had them on a few Model A engines and all of my V8 Flatheads. Repairs become a huge hassle.

I glue them in to give the coarse threads more purchase. The gasket shellac works well for that, and is easier to get free than Loctite.