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-   -   street motor compression (https://www.racingjunk.com/forums/showthread.php?t=17492)

zano 06-05-2007 10:48 AM

street motor compression
 
bought street motor from bowers 632 c.i. was suppose to have 10.5 compression it has 11.3 is this to much for street?

lotsof454sss 06-05-2007 10:49 AM

I just have to ask....Did you read all the post here before you bought your engine??

zano 06-05-2007 10:55 AM

read posts
 
some are my posts bought engine way before posts just got it a couple of weeks ago

bjuice 06-05-2007 11:25 AM

to answer your question...NO...its not too much for a naturally aspirated street engine...you want to make sure you keep good gas in the motor...the Amoco 93 octane white gas is good stuff...11 to 1 compression is about the highest you would want to go on pump gas street motor ( my opinion).....do not SLIP and put some cheap gas in that motor cause its right there on the border...


i do not know if you have access to racing gas at the pump..
here in my home town they have leaded racing gas 110 ast the pump at some stations....it would not be a bad idea to run a couple of gallons of 110 with every 10 gallons of 93 octane...

i mean look....you need some compression to make some decent HP....I DO NOT think you would have appreciated that 632ci motor if it were a 9.5 compression motor..it would have been a slug...( my opinion again)
not taking up for bowers just telling you how it goes...compression makes HP.......understanding there is a limit to what a street motor needs to be.

i have had more than one 11 to1 compression street motors..as a matter of fact i had some of the fastest 406ci street pump gas 11 to 1 motors in town at one time..

just curious...how or who did you have figure the compression when you got it back from bowers ?

Brian

sp2816 06-05-2007 11:31 AM

zano wrote:

bought street motor from bowers 632 c.i. was suppose to have 10.5 compression it has 11.3 is this to much for street?
Other factors come into play, such as the camshaft timing and fuel that you are planning on running. But, IMHO for "street" driving and 93 octane fuel, I would say that it is too much compression.

As I calculate, the overall chamber volume needs to decrease by about 10cc's to get to 10.5:1 and 18cc's to get to 10:1.

Bill M

zano 06-05-2007 12:28 PM

figuring compression
 
bowers just sent me the cam card dyno and compression ratio yesterday it was suppose to be 10.5 he said its 11.3 ross flat top pistons comp can 785 766 gross lift 278 290 duration at .05 also seems like alot of cam for the street dynoed 945 at 6000 rpm comp cam says it will not idle good bowers says on dyno it idled at 850 real nice also said flat top pistons burn better and alum. heads them 2 things make it so you can get away with 11.3 comp. i hope he is right what do you think no racing gas around here but 94 octane sunoco

mcracecars 06-05-2007 12:56 PM

I would have a difficult time beleiving the engine has or is anything he says it is.
It is probably a big block of some kind.... check it out...

woodsman 06-05-2007 01:14 PM

zano he has never told the truth before why would he start now just my 2 cents. Wesley

bjuice 06-05-2007 02:11 PM

ZANO- have you run the motor ? and if so what have you used as fuel ? or what was the fuel used on the dyno ?

also street use means different things to different people...to me street use means driving it to a local cruise inn on a Saturday..
for some it means driving it back and forth every day to work and 500 miles one way to a vacation spot.


Brian

zano 06-05-2007 02:15 PM

compression
 
it sounds like nobody really knows and your right i think this is what i got. i do know its a merlin III block victor heads ported intake i hope the rest is right. i should have the car back together in a month or less i'll let you know


over and out zane


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