User Login    
 + Register
  • Main navigation
Login
Username:

Password:


Lost Password?

Register now!
Fast Search
Slow Search
Google Ad



Browsing this Thread:   1 Anonymous Users



« 1 2 (3)


Re: compression ratio on 98 octaine
Just can't stay away
Joined:
2008/9/29 4:57
Group:
Registered Users
Posts: 81
Offline
exactly but you can get real thin head gaskets

Posted on: 2011/6/14 8:59
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
Home away from home
Joined:
2009/6/9 10:55
Group:
Registered Users
Posts: 409
Offline
I know mate, I'm not having a stab at you, I'm just wondering what Pigdogs 'much better and safer ways of increasing the engine power' ideas are, considering you drive a speedway car and are limmited in what engine machining you can actually do. Cheers.

Posted on: 2011/6/14 9:07
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
No life (a.k.a. DattoMaster)
Joined:
2007/1/22 23:06
From East New Britain, Papua New Guinea
Group:
Registered Users
Posts: 6994
Offline
I always thought sunny02 and GG-datsun were the same person?

There isn't much else to do hey (without breaching the rules).

I don't know what your regulations actually are but things like thinner head gaskets, flat faced valves would be the go.

Not sure if you can try and take a bit more volume with a deeper sitting spark plug- and I don't even know if those are available.

Second thing would be to take a good look at what combustion chambers shapes are available to you, the H75 head holds alot of it's volume in the very last part of the combustion chamber (closest to the deck). Taking that large open circle of volume off may yield a lower volume at the 60 thou surface milling limit, compared to if you were to machine say a H89/GX. But having said that the H75 holds approx 2cc more than the H89 so maybe it won't work out as well, worth a look though?

Also surface milling on an angle that would remove most of the larger side of the combustion chamber (on a H89/GX) may result in a lower volume but I haven't looked into that. Coming to think of it that may not work either.

Are there regulations against having the pistons proud of the deck height?

Posted on: 2011/6/14 9:15
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
Just can't stay away
Joined:
2007/4/27 4:34
From Melbourne, Australia
Group:
Registered Users
Posts: 92
Offline
what you need to do is dilute 98 down to 97 by mixing it with 91 (i don't know the ratios)

then skim it until it starts to ping on the 97 and thats your safe limit

Posted on: 2011/6/14 10:18
_________________
"yeah but there will be free candy right!?"
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
No life (a.k.a. DattoMaster)
Joined:
2004/10/28 11:35
From Geelong, Vic
Group:
Registered Users
Posts: 6288
Offline
what i meant by much safer ways to increase power, were getting more air in rather than compressing the air more. as there was no mention of speedway regs or anything when i made that reply

but i guess, ask a vague question, get a vague answer

Posted on: 2011/6/14 10:58
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
Just can't stay away
Joined:
2008/9/29 4:57
Group:
Registered Users
Posts: 81
Offline
pistons are allowed up to 10 thou above the block.But mine are currently level.Wondering how much 10 thou will increase my compression ratio.

Posted on: 2011/6/14 10:58
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
No life (a.k.a. DattoMaster)
Joined:
2004/10/28 11:35
From Geelong, Vic
Group:
Registered Users
Posts: 6288
Offline
you know there are quite easy ways to work that out. im sure you can find an online compression ratio calculator that will actually take into account all of your particular engine variables. as no one else will be able to accurately answer that question without knowing more info

can you get domed pistons? can you weld up the combustion chamber? both of these will effect the comp ratio alot more than shaving a whole heap off the head

Posted on: 2011/6/14 11:05
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
No life (a.k.a. DattoMaster)
Joined:
2008/2/10 10:23
From sydney.nsw
Group:
Registered Users
Posts: 1092
Offline
bige 0412 864 741

Posted on: 2011/6/14 11:12
_________________
A.T.E RACE ENGINES: ( " AUST 1 " 2010 ) A15 GO THE DATTOS... 0412 864 741
Transfer the post to other applications Transfer


Re: compression ratio on 98 octaine
Just can't stay away
Joined:
2008/9/29 4:57
Group:
Registered Users
Posts: 81
Offline
cant used domed pistons or weld up combustion chamber.

Posted on: 2011/6/14 11:34
Transfer the post to other applications Transfer



« 1 2 (3)



You can view topic.
You cannot start a new topic.
You cannot reply to posts.
You cannot edit your posts.
You cannot delete your posts.
You cannot add new polls.
You cannot vote in polls.
You cannot attach files to posts.
You cannot post without approval.

[Advanced Search]