Cylinder cracking on 61x/62T

Polish jet pilot

Polish jet pilot

4aces4aces4aces4aces4aces
Location
Warsaw, Poland
Hi all,

I am soon to finalize my engine build (not too much to talk about - 727cc, Bpipe, porting, other small goodies). Not sure whether I will have 400 usd for a girdled head kit now. I was considering milling my virgin OEM head. Will my cylinder crak if I do not use a girdle kit?

All advice is welcome. Maybe some tips and tricks to imptrove the OEM head?

Thank you!
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
You can find used heads for about half of that on here. Do a search on it though. There are some good threads on this with some good (bad) pictures in them. Bottom line is there are plenty of people that have successfully run without girdled heads but there are also plenty of people that have unsuccessfully run without girdled heads. The risk is yours.
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
tshank123 said:
I will never buy a used head again. Just spend the money for a new one.
Click to expand...

Why? Short of you buying a head without all the components and/or a head with the wrong or pitted domes, I don't understand what could possibly go wrong. $400 vs $200... I can accept some carbon build up or some paint with heat damage on it for that kind of price difference. In fact I did and it's been working like a champ ever since.
 
jetski9010

jetski9010

Team RTYD
Location
Lancaster PA
I would rather buy new also. I have seen where used ones blow orings and cause leaks. I am sure there are a lot of people that bought used ones that had them work well. I see ADA heads on here sell for $250 all the time and you usally need new o rings too. For $344 I would get the brand new ADA head and also have a better chance of not being towed in to the dock.
 
kawyjunki

kawyjunki

NODNARB
Location
Springfield,Branson,Mo
Go new. Had a used ADA head and fought it for two months, blowing o-rings. Would make it out about 100yrds and then blow. Not fun!!! Didn't realize it was the head shell that was wore until Chuck measured it when building my stroker and deemed it worn extensive.
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
Well I'm not a huge fan of ADA personally since you loosen the cylinder when loosening the head. However, in all my reading on this forum, I've never once read of someone wearing out a head. Is this just an ADA thing or do all heads "wear out"? What actually wears out?
 
kawyjunki

kawyjunki

NODNARB
Location
Springfield,Branson,Mo
Where the dome sets in the head shell. I guess it has a tendency to "rock" (for lack of a better word) around in there over time, and wear on the shell where it seats. IDK how.... I was told that detonation is a big factor to this.
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
kawyjunki said:
Where the dome sets in the head shell. I guess it has a tendency to "rock" (for lack of a better word) around in there over time, and wear on the shell where it seats. IDK how.... I was told that detonation is a big factor to this.
Click to expand...

Wow makes me glad (in a way) that my domes aren't removable. If that's true, that is inexcusable in my book. Sounds like the manufacturers need to work on their tolerances or figure out a better way to mount the domes. You may save some money with an o-ring head over gaskets but it doesn't do you any good if you have to replace the entire head every couple years because the shell wears out and blow o-rings constantly.
 
wsuwrhr

wsuwrhr

Purveyor of the Biggest Brapp
Location
Alta Loma, working in Upland
kawyjunki said:
Go new. Had a used ADA head and fought it for two months, blowing o-rings. Would make it out about 100yrds and then blow. Not fun!!! Didn't realize it was the head shell that was wore until Chuck measured it when building my stroker and deemed it worn extensive.
Click to expand...



What "wears out"

kawyjunki said:
Where the dome sets in the head shell. I guess it has a tendency to "rock" (for lack of a better word) around in there over time, and wear on the shell where it seats. IDK how.... I was told that detonation is a big factor to this.
Click to expand...

Nevermind, I see the answer after I kept going.

Brian
 
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Polish jet pilot

Polish jet pilot

4aces4aces4aces4aces4aces
Location
Warsaw, Poland
Yesterday we pulled amotor off a 760cc racing ski. It has all the goodies (ported big bore 61x, girdeled head, dry pipe, MSD, etc) - eben though the cylinder had RIVA girdeled head system the front cylinder cracked about 4 inches. It was cracked in the middle of the cylinder height. Do you think that it is the same type of cracking as with the standard 61x cyl? Is the place of cracking the same as in standard cylinders??

I guess there is more to cylinder cracking than just not using a girdeled head - I think deto causes all this cracking!
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
The girdled head is primarily there to prevent cracking on the lower flange on the intake side. Cracking elsewhere is most likely caused by water freezing in the water jackets. Frosty posted some pics a while back of when his cylinder cracked so you can get an idea of exactly where.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
The ADA girdled system is a pinch type hold down for sandwiching the cylinder. (1 piece stud all the way through the head to the cases)
I have never seen a ADA headed cylinder crack, come loose or break a stud-YES but that is rare nowadays as the new rolled thread studs don't break anymore like the cut thread studs did, and go up on the torque settings to 42 FT-LBS and not use what ADA said in their instructions.
The Riva girdled system is a tie down type to hold the cylinder. (base bolts or studs with threaded top nuts, then uses tie bolts from head to threaded top nuts)
Most of the time, the tie system does not use enough torque to hold the cylinder down, bolts are often 8mm and not 10mm in diameter. So I don't like tie down system, as it can help cylinder cracking but will not prevent it from cracking.
 
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