8 Second Stock Block 109

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I wanted to know who has done it and how many times.. There is only three that I know of personally that have done this with a stock block. "There is one guy touting his 8 sec 109 but haven't seen proof yet."


Been reading alot of stuff about this said individual...Is he really that disliked???:confused:

Being an engineer, I wanna ask a question about the 109's. I see most of the guys posting in this thread are well educated in the engines and pretty darn fast. What is the weak point, of the block, at the 8 sec power level? Bottom end or the 8 head bolts? Just wondering how much stronger the girdle makes it and if adding 2 splayed bolts thru the girdle and into the billet caps would gain us anything? Of course, you would need custom made caps, but thats what I do. I make anything I need. Just need a steel type and hardness to start. Any thoughts would be great. If this is of no discussion, my bad.

Coach:biggrin:

For us with Chris Hogelands motor it's the block webbing. 3 broken blocks without hurting any of the rotating assembly. He tried 1/2 head studs without success. Stock caps or billet caps didn't matter, actually the stock caps looked better after some abuse. Tried dowel pinning the caps without success. So far the girdle and stock caps seem to work the best. The latest engine has a girdle that was cut from a harder material and the issue was found that has caused the prior engine failures from being shaken apart. We were looking for issues with the block, turns out it was with the crank. New engine is going back together.

We're in a situation where it's cheaper to play with this than it is to play with the Stage 2. Engine blocks are cheap and easy to find. Chris has taken up the engine machining himself so if we want to try something, he goes to the shop and handles it himself. There is a stage 2 engine already assembled and ready to go when we give up on the 109 stuff.
 
For us with Chris Hogelands motor it's the block webbing. 3 broken blocks without hurting any of the rotating assembly. He tried 1/2 head studs without success. Stock caps or billet caps didn't matter, actually the stock caps looked better after some abuse. Tried dowel pinning the caps without success. So far the girdle and stock caps seem to work the best. The latest engine has a girdle that was cut from a harder material and the issue was found that has caused the prior engine failures from being shaken apart. We were looking for issues with the block, turns out it was with the crank. New engine is going back together.

We're in a situation where it's cheaper to play with this than it is to play with the Stage 2. Engine blocks are cheap and easy to find. Chris has taken up the engine machining himself so if we want to try something, he goes to the shop and handles it himself. There is a stage 2 engine already assembled and ready to go when we give up on the 109 stuff.

were does the block bracks? is it buy the motor mount or buy the main caps?
 
# 2 main webbing. From the oil pick up to the cam bearing. That is where mine have all broke.
 
For us with Chris Hogelands motor it's the block webbing. 3 broken blocks without hurting any of the rotating assembly. He tried 1/2 head studs without success. Stock caps or billet caps didn't matter, actually the stock caps looked better after some abuse. Tried dowel pinning the caps without success. So far the girdle and stock caps seem to work the best. The latest engine has a girdle that was cut from a harder material and the issue was found that has caused the prior engine failures from being shaken apart. We were looking for issues with the block, turns out it was with the crank. New engine is going back together.

We're in a situation where it's cheaper to play with this than it is to play with the Stage 2. Engine blocks are cheap and easy to find. Chris has taken up the engine machining himself so if we want to try something, he goes to the shop and handles it himself. There is a stage 2 engine already assembled and ready to go when we give up on the 109 stuff.

I can def see the webbing being a problem area. If it werent for the pick-up tube on #2 and the dipstick on #3. we might be able to machine an area and cross-bolt the 2 center caps. That along with the girdle would improve any crank flex, but the fact the you guys are cracking them from the cam on down, even crossbolting isnt solving that issue.

Dusty, I dont think that a harder steel on your girdle is a bad thing, but I would have probably used a case-hardened steel. Thats where after its machined, its heat-treated and only forms a hardness of about 0.030-0.040 thick and leaves the middle as it was. This allows for strength without breaking or flexing. I do not know what RJC makes them out of now. It may be a material that can be case-hardened. I would have to call.
I was just trying to figure out if there were a way to help you guys go faster by thinking outside the box. Im not done thinking yet, but my head hurts right now...LOL

:biggrin:
 
I don't have a log of how many passes I've made in the mid to low 9s without block failures (~6yrs). Don seems to have figured out a few things with these engines and it keeps on going.

knock on wood, It may split on my next pass..
 
I don't have a log of how many passes I've made in the mid to low 9s without block failures (~6yrs). Don seems to have figured out a few things with these engines and it keeps on going.

knock on wood, It may split on my next pass..

That block of yours should go in the BMS hall of fame:biggrin:
 
Can we throw oem mounted motor mounts versus front/mid/rear plates into the topic?


K.
 
For us with Chris Hogelands motor it's the block webbing. 3 broken blocks without hurting any of the rotating assembly. He tried 1/2 head studs without success. Stock caps or billet caps didn't matter, actually the stock caps looked better after some abuse. Tried dowel pinning the caps without success. So far the girdle and stock caps seem to work the best. The latest engine has a girdle that was cut from a harder material and the issue was found that has caused the prior engine failures from being shaken apart. We were looking for issues with the block, turns out it was with the crank. New engine is going back together.

We're in a situation where it's cheaper to play with this than it is to play with the Stage 2. Engine blocks are cheap and easy to find. Chris has taken up the engine machining himself so if we want to try something, he goes to the shop and handles it himself. There is a stage 2 engine already assembled and ready to go when we give up on the 109 stuff.

Dusty, on a part like a girdle it's all about stiffness, not yield strength. I doubt you have ever removed a girdle and found it permanently bent - if so, ignore this, and please post a picture :-). Pretty much all steel has the same stiffness (Young's Modulus of Elasticity) so going to higher carbon steel than 1018 or going to 4340 chrome moly or case hardening isn't really going to help. The main thing that determines stiffness is the dimension perpendicular to the flex direction, or in this case the thickness of the girdle. The stiffness is proportional to the cube of the thickness, so doubling the thickness gives you eight time the stiffness. Making it wider (making the windows between the caps and the pan rail smaller) doesn't help nearly as much since stiffness is just proportional to this dimension so making it completely solid would only roughly double how stiff the girdle would be. I can't comment on how much adding extra bolts to tie the girdle to the block and caps would help, but I'd definitely try making one twice as thick (or 2.7 times as thick if you want a factor of 20 gain in stiffness). You could try keeping the pan rail area the same thickness and adding ribs down the cap bolts but please email me to discuss this if you want to try it; I can calculate the relative stiffness of various designs for you before you make chips.
 
I can def see the webbing being a problem area. If it werent for the pick-up tube on #2 and the dipstick on #3. we might be able to machine an area and cross-bolt the 2 center caps. That along with the girdle would improve any crank flex, but the fact the you guys are cracking them from the cam on down, even crossbolting isnt solving that issue.

Dusty, I dont think that a harder steel on your girdle is a bad thing, but I would have probably used a case-hardened steel. Thats where after its machined, its heat-treated and only forms a hardness of about 0.030-0.040 thick and leaves the middle as it was. This allows for strength without breaking or flexing. I do not know what RJC makes them out of now. It may be a material that can be case-hardened. I would have to call.
I was just trying to figure out if there were a way to help you guys go faster by thinking outside the box. Im not done thinking yet, but my head hurts right now...LOL

:biggrin:

To be even more specific, the crack has always been the oil feed hole from the main journal to the cam journal. It cracks in the webbing on one side of the oil tunnel and cracks outward. Loss of oil pressure is the sign.

The girdles are flexing and have memory. You can shim the girdle for the proper pan rail clearance. If you take the girdle back off for any work it has to be re-shimmed when you re-install it. So the girdle is cupping. The material the local shop is using will not do that. It will be installed with no shims and have no flex. We're hoping it will help with cap walk.
 
To be even more specific, the crack has always been the oil feed hole from the main journal to the cam journal. It cracks in the webbing on one side of the oil tunnel and cracks outward. Loss of oil pressure is the sign.

The girdles are flexing and have memory. You can shim the girdle for the proper pan rail clearance. If you take the girdle back off for any work it has to be re-shimmed when you re-install it. So the girdle is cupping. The material the local shop is using will not do that. It will be installed with no shims and have no flex. We're hoping it will help with cap walk.

Wow, I'm shocked the girdle could flex enough to get past the yield point. I wonder if it is internal stresses from the machining? If so, you could machine it then have it annealed and heat treated to stress relieve it, then grind it flat on a surface grinder. I still say if the girdle is flexing make it thicker. Good luck with it, Dusty, and let us know how it turns out.
 
Wow, I'm shocked the girdle could flex enough to get past the yield point. I wonder if it is internal stresses from the machining? If so, you could machine it then have it annealed and heat treated to stress relieve it, then grind it flat on a surface grinder. I still say if the girdle is flexing make it thicker. Good luck with it, Dusty, and let us know how it turns out.

There are issues with the crank that is the cause of all of the vibration causing the block failures. The girdle flexing may not even be an issue but we have someone wanting to build something for fun so we're not gonna stop him.:D
 
There are issues with the crank that is the cause of all of the vibration causing the block failures. The girdle flexing may not even be an issue but we have someone wanting to build something for fun so we're not gonna stop him.:D

I hope your not talking about the project that Chris and I were hashing out?!?!?!? That would be alot of time and $$$ and we'er not even sure it will work. We can try it, but I will need some time to get all the ducks in a row.
If your talking about something else...My Bad.

:biggrin:
 
I hope your not talking about the project that Chris and I were hashing out?!?!?!? That would be alot of time and $$$ and we'er not even sure it will work. We can try it, but I will need some time to get all the ducks in a row.
If your talking about something else...My Bad.

:biggrin:

It was a little different:biggrin:
 
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