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Steel plate between head and block?

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It's not his accent as much as the way he ends each word, kinda funny. Otherwise he raises a good point which I've also heard argued by other people about the block being very susceptible to warpage and flexing.

What he said at the beginning was basically how the bolt/stud holes don't go far enough into the block to allow the clamping force from the head bolts to distribute more evenly through the block. Or at least that's what I'm understanding. I've seen some engine designs where the head bolts go all the way through the block and thread into the actual crank girdle, essentially sandwiching the block.

What he said about the benefits of using stock head bolts for their ability to stretch just a bit is also interesting. The added stretch would allow (somewhat) for the block and head to "dynamically warp" together under very high cylinder pressures. Whereas reinforced bolts or studs such as ARPs would not allow for this extra "give" of the metals, which means you'd get uneven warpage and push more pressure against the headgasket. I'm actually running stock (but not OEM) headbolts and I'm curious to see if they'll hold up to when I increase my boost pressure to 1.5/1.7 bar.

I think it may be worth experimenting with drilling out the bolt holes deeper to allow the use of a longer bolt. Or, if possible, drill all the way through the block and incorporate a custom girdle, as long as there's room for the rotating assembly. I know that at least one of the bolt holes is the oil feed for the head, so actually that might make this impossible. :hmm:
 
Felt like he mumbled at times LOL. That's interesting and I'd like to actually see that set up. You shouldn't have any issues at all at that boost level with a hg and studs. I'm sure most of us are running much boost with the same. These guys are running 3 bar at 4k which must feel insane and probably no lag too.
 
What he said about the benefits of using stock head bolts for their ability to stretch just a bit is also interesting. The added stretch would allow (somewhat) for the block and head to "dynamically warp" together under very high cylinder pressures. Whereas reinforced bolts or studs such as ARPs would not allow for this extra "give" of the metals, which means you'd get uneven warpage and push more pressure against the headgasket. I'm actually running stock (but not OEM) headbolts and I'm curious to see if they'll hold up to when I increase my boost pressure to 1.5/1.7 bar.

This is why it's important to have a deck plate when finish honing the cylinder bores. You need to accommodate the distortion of the block so when you bolt the head on the bores stay perfectly round.

Regarding the video, super interesting that they reinforced the block with a steel plate and used steel liners sprayed with nikasil. Not sure if the Darton dry sleeves were available to them when they made that decision. This video, coupled with the Motive DVD video about the block thickness and hardness definitely shed some light on the 4G's strengths and weaknesses.

https://www.dsmtuners.com/threads/4g63-block-test-thickness-hardness-etc.527310/
 
This is why it's important to have a deck plate when finish honing the cylinder bores. You need to accommodate the distortion of the block so when you bolt the head on the bores stay perfectly round.

Regarding the video, super interesting that they reinforced the block with a steel plate and used steel liners sprayed with nikasil. Not sure if the Darton dry sleeves were available to them when they made that decision. This video, coupled with the Motive DVD video about the block thickness and hardness definitely shed some light on the 4G's strengths and weaknesses.

https://www.dsmtuners.com/threads/4g63-block-test-thickness-hardness-etc.527310/
This is correct, this is the reason for torque plate honing, we know the limit of stock head bolts vs aftermarket studs, the studs are necessary on high hp cars period, no two ways about it, distortion or not, a blown head gasket is going to end your day, cylinder block distortion will not, it all depends on what you need to accomplish, if the guy is inferring that stock bolts are somehow better than studs then he is way out of his league on the 4g63 forums, we been there done that for a long time now.
 
It was great to hear someone, from another motor sport perspective, think outside the box, build it, race it, and share their information. 700ft. lb @ 4,000rpm! What a street beast that would make.
 
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