c 460 heads

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c 460 heads

Post  procharger 528 on Sun 16 Sep 2018 - 19:06

hi i have a question for the C head guys
i have been running a 572 C headed engine with a f3 pro charger,
we have been having a lot of trouble burning head gaskets out and random spark plugs
it has copper head gaskets with o ring groves and receivers,
its got mechanical injection 3 injectors per cylinder
to stop it burning we have added a lot of fuel so much that it runs out the pipes
we tried thicker head gaskets which seems to have helped a little
i was told to soften up the chambers a bit to get rid of some of the squish..machine it to a 7 degree angle..
timing is set at 28
compression is 11.1
38 pounds boost
NGK 10 plug with 20 thou gap
MSD 10
was hoping someone can explain if its a good idea before i get it done
thanks for any help
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Re: c 460 heads

Post  BOSS 429 on Sun 16 Sep 2018 - 21:24

are you sure its 11.1?  for sure timing is 28? very easy could be too much timing.
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Re: c 460 heads

Post  procharger 528 on Sun 16 Sep 2018 - 22:32

yes 11.1 compression we have had it at 26 timing didn't seem to help much made it a little flat...slowed the 60 foot down...
cam and pistons were all supplied by Steve Morris race engines...
exhaust probes say its at 1100-1200 degree on the line sometimes a little higher and when you leave it drops a little..as boost comes on the fuel pressure rises...two injectors are boost reference...
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Re: c 460 heads

Post  BBFTorino on Sun 16 Sep 2018 - 22:54

procharger 528 wrote:hi i have a question for the C head guys
i have been running a 572 C headed engine with a f3 pro charger,
we have  been having a lot of trouble burning head gaskets out and random spark plugs
it has copper head gaskets with o ring groves and receivers,
its got mechanical injection 3 injectors per cylinder
to stop it burning we have added a lot of fuel so much that it runs out the pipes
we tried thicker head gaskets which seems to have helped a little
i was told to soften up the chambers a bit to get rid of some of the squish..machine it to a 7 degree angle..
timing is set at 28
compression is 11.1
38 pounds boost
NGK 10 plug with 20 thou gap
MSD 10
was hoping someone can explain if its a good idea before i get it done
thanks for any help

Is this setup a 10 bolt deal, or an 18 bolt??

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Re: c 460 heads

Post  rmcomprandy on Mon 17 Sep 2018 - 0:26

procharger 528 wrote:hi i have a question for the C head guys
i have been running a 572 C headed engine with a f3 pro charger,
we have  been having a lot of trouble burning head gaskets out and random spark plugs
it has copper head gaskets with o ring groves and receivers,
its got mechanical injection 3 injectors per cylinder
to stop it burning we have added a lot of fuel so much that it runs out the pipes
we tried thicker head gaskets which seems to have helped a little
i was told to soften up the chambers a bit to get rid of some of the squish..machine it to a 7 degree angle..
timing is set at 28
compression is 11.1
38 pounds boost
NGK 10 plug with 20 thou gap
MSD 10
was hoping someone can explain if its a good idea before i get it done
thanks for any help

11/1 is WAY to high of a static compression ratio for 38 pounds of boost.  
That much boost will greatly raise the intake charge heat level and that cylinder pressure to well over 30/1 compression ratio.

A static ratio of about 6/1 would be more in line with 38 POUNDS of boost.

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Re: c 460 heads

Post  BBFTorino on Mon 17 Sep 2018 - 1:02

rmcomprandy wrote:
procharger 528 wrote:hi i have a question for the C head guys
i have been running a 572 C headed engine with a f3 pro charger,
we have  been having a lot of trouble burning head gaskets out and random spark plugs
it has copper head gaskets with o ring groves and receivers,
its got mechanical injection 3 injectors per cylinder
to stop it burning we have added a lot of fuel so much that it runs out the pipes
we tried thicker head gaskets which seems to have helped a little
i was told to soften up the chambers a bit to get rid of some of the squish..machine it to a 7 degree angle..
timing is set at 28
compression is 11.1
38 pounds boost
NGK 10 plug with 20 thou gap
MSD 10
was hoping someone can explain if its a good idea before i get it done
thanks for any help

11/1 is WAY to high of a static compression ratio for 38 pounds of boost.  
That much boost will greatly raise the intake charge heat level and that cylinder pressure to well over 30/1 compression ratio.

A static ratio of about 6/1 would be more in line with 38 POUNDS of boost.
I'm thinking that if it is a 10 bolt block/head combo, the extreme cylinder pressure is lifting the head and getting past the gasket.
This is common on high boost small block Fords too.

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Re: c 460 heads

Post  old blue on Mon 17 Sep 2018 - 3:20

Yes i agree, sounds like its lifting the heads an to much static compression, giving the mix id say it worth looking in to. I try to switch to cometics if possible when freshening. Impressive  build though. How does it feel after the 330, i bet its addictive.
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Re: c 460 heads

Post  procharger 528 on Mon 17 Sep 2018 - 14:30

hi
the engine is a 18 bolt eliminator block...
it runs on methanol...when we add a lot of fuel it seems to live but we dont have a good tuning window...
milks the oil pretty bad...
most of the door slammer guys i have talked to over here say there roots set ups are in the 11 to 12.1 compression range...
we have curved the boost down it was at 42 to start with...we were looking at going to efi to try and sort some of the tuning...
i do like the mechanical injection nice and simple...plus the efi is a lot of money to run methanol..
the heads are getting well used now thats why i was thinking about the soft chamber set up..
thanks for the reply's
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Re: c 460 heads

Post  rmcomprandy on Mon 17 Sep 2018 - 14:59

procharger 528 wrote:hi
most of the door slammer guys i have talked to over here say there roots set ups are in the 11 to 12.1 compression range...

Not with using 38 pounds of boost.

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Re: c 460 heads

Post  ChrisH on Wed 19 Sep 2018 - 12:21

38 psi of boost is ~2.6 atmospheres of pressure, or 2.6 times what a NA motor sees.
therefore you are craming 2.6 times more air in the engine than you could at NA condtions.
If you multiply this 2.6 by your compression ratio of 11 and this makes your effective compression ratio 29:1 (by adiabatic volume change alone). take in account the true increase in temperature and like Randy stated and you are over 30:1

Randy's 6:1 would give you a static (and adiabatic ) compression ratio of 15.6:1 (no temperature change)

This is certainly a simplification, but i hope it gives some clarity on what is going on.
i am certainly no expert on engines, let alone boosted engines. But i am very aware of equations of state and the laws of thermodynamics and this seems to be something that should be looked at

hope it helps

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Re: c 460 heads

Post  procharger 528 on Wed 19 Sep 2018 - 14:31

so i can get the boost down to around 30 psi pretty easy and pull some more timing...
i have machined the block o ring groves bigger to a 2 mm wire with a bigger receiver grove
i have 060 copper head gaskets to go on it...im still undecided on getting the head chamber machined...doing this will help get the compression down a little and from what i understand machining the squish will also reduce detonation and increase the flame travel??
i have also added a bigger fuel pump 18GPH instead of the 14GPH i was using...
our race season is about to start again soon so i want to get the heads back on and running again.
i have also changed to a better clutch than i had, now a 3 disc crower and a 4 speed lenco with a lower first gear...that should help with not loading up the engine too much on the start...
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Re: c 460 heads

Post  68galaxie on Wed 19 Sep 2018 - 17:34

Talk to someone who has experience building supercharged methanol engines.
I would be very hesitant to listen to anyone who doesn't have relevant experience.
Top alcohol builds are in the 10.5:1 region and large boost levels, large camshafts etc...
Talk to Steve Morris. He builds these things. I am sure he can tell you if your compression ratio is or isn't an issue.

Good luck with this - sounds very interesting.

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Re: c 460 heads

Post  BBFTorino on Thu 20 Sep 2018 - 14:40

procharger 528 wrote:so i can get the boost down to around 30 psi pretty easy and pull some more timing...
i have machined the block o ring groves bigger to a 2 mm wire with a bigger receiver grove
i have 060 copper head gaskets to go on it...im still undecided on getting the head chamber machined...doing this will help get the compression down a little and from what i understand machining the squish will also reduce detonation and increase the flame travel??
i have also added a bigger fuel pump 18GPH instead of the 14GPH i was using...
our race season is about to start again soon so i want to get the heads back on and running again.
i have also changed to a better clutch than i had, now a 3 disc crower and a 4 speed lenco with a lower first gear...that should help with not loading up the engine too much on the start...

Wow, your car is like a Pro Mod deal!!

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Re: c 460 heads

Post  procharger 528 on Thu 20 Sep 2018 - 15:00

68galaxie wrote:Talk to someone who has experience building supercharged methanol engines.
I would be very hesitant to listen to anyone who doesn't have relevant experience.
Top alcohol builds are in the 10.5:1 region and large boost levels, large camshafts etc...
Talk to Steve Morris. He builds these things. I am sure he can tell you if your compression ratio is or isn't an issue.

Good luck with this - sounds very interesting.

these specs for the engine were from Steve Morris the cam is pretty big in it now 904 lift..he supplied most of the parts...
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Re: c 460 heads

Post  procharger 528 on Thu 20 Sep 2018 - 15:03

BBFTorino wrote:
procharger 528 wrote:so i can get the boost down to around 30 psi pretty easy and pull some more timing...
i have machined the block o ring groves bigger to a 2 mm wire with a bigger receiver grove
i have 060 copper head gaskets to go on it...im still undecided on getting the head chamber machined...doing this will help get the compression down a little and from what i understand machining the squish will also reduce detonation and increase the flame travel??
i have also added a bigger fuel pump 18GPH instead of the 14GPH i was using...
our race season is about to start again soon so i want to get the heads back on and running again.
i have also changed to a better clutch than i had, now a 3 disc crower and a 4 speed lenco with a lower first gear...that should help with not loading up the engine too much on the start...

Wow, your car is like a Pro Mod deal!!
lol i wish it was a pro mod....its a little heavy for that all steel body...
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