big_truxx
1/2 ton status
What's the stock comp ratio of an 89 tbi 454? If it makes any difference the original motor in an 89 crew dually scotsdale model 
CK5
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stock comp ratio 454 tbi?
- Thread starter big_truxx
- Start date
LongIslander26
1/2 ton status
comp ratio
It's probably in the neighborhood of 8-8.5:1. I can look into it further to get you an exact number.
It's probably in the neighborhood of 8-8.5:1. I can look into it further to get you an exact number.
big_truxx
1/2 ton status
that sucks. I was hoping it'd be up around 9 
I know gm's specs for the 350 mr goodwrench was 8.5. I may have to rebuild the whole motor anyway so mightbe good to up the compression some 10:1 would be about right I think
I know gm's specs for the 350 mr goodwrench was 8.5. I may have to rebuild the whole motor anyway so mightbe good to up the compression some 10:1 would be about right I think LongIslander26
1/2 ton status
Big Block rebuild.
Zero deck the block and use flattop pistons, a thin head gasket, and watch your cam lift, that should get you in the ballpark.
Zero deck the block and use flattop pistons, a thin head gasket, and watch your cam lift, that should get you in the ballpark.
k20
3/4 ton status
7.9:1
230hp @ 3600 rpm
385ft/lbs @ 1600 rpm
230hp @ 3600 rpm
385ft/lbs @ 1600 rpm
big_truxx
1/2 ton status
I am thinking since it has 163k on it and was ran hot and quite possibly needs head gaskets, may as well tear it down and put a couple other parts in the rebuild when I can afford. I just played with my desktop dyno 2000 and with pocket porting and large valves, 10:1 comp, headers, summit 1300 cam, and with the 660cfm setting using dual plane setting for induction it brings up roughly 425hp and 500 lb ft tq.. 
doesnt seem like that little work would produce that much power but... I dunno.
doesnt seem like that little work would produce that much power but... I dunno.LongIslander26
1/2 ton status
454
10:1 CR is going to require some high octane gas in Maine close to sea level, especially with a low duration cam which will raise your dynamic CR . What's the cam specs on that summit cam?
10:1 CR is going to require some high octane gas in Maine close to sea level, especially with a low duration cam which will raise your dynamic CR . What's the cam specs on that summit cam?
big_truxx
1/2 ton status
yer right. I forgot about that. 
Just ran a different parts list of 8:1 comp ratio, heads pocket ported w/ large valves and headers w/ the stock cam option and its up to about 325hp and 470 lb ft tq now assuming that in overheating the rings and all are still ok, that would work out very well w/ the stock tbi setup 
Just ran a different parts list of 8:1 comp ratio, heads pocket ported w/ large valves and headers w/ the stock cam option and its up to about 325hp and 470 lb ft tq now assuming that in overheating the rings and all are still ok, that would work out very well w/ the stock tbi setup LongIslander26
1/2 ton status
454
Looks like a stump puller to me!
Looks like a stump puller to me!
big_truxx
1/2 ton status
Brand: Summit
Product Line: Summit Camshafts
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-4,000 RPM
Intake Duration 050 inch Lift: 208
Exhaust Duration 050 inch Lift: 218
Duration at 050 inch Lift: 208 int./218 exh.
Advertised Intake Duration: 266
Advertised Exhaust Duration: 276
Advertised Duration: 266 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.475
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.500
Valve Lift with Factory Rocker Arm Ratio: 0.475 int./0.500 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash (in): 0.000
Exhaust Valve Lash (in): 0.000
Computer Controlled: No
Quantity: Sold individually.
cam specs
Product Line: Summit Camshafts
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 1,500-4,000 RPM
Intake Duration 050 inch Lift: 208
Exhaust Duration 050 inch Lift: 218
Duration at 050 inch Lift: 208 int./218 exh.
Advertised Intake Duration: 266
Advertised Exhaust Duration: 276
Advertised Duration: 266 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.475
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.500
Valve Lift with Factory Rocker Arm Ratio: 0.475 int./0.500 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash (in): 0.000
Exhaust Valve Lash (in): 0.000
Computer Controlled: No
Quantity: Sold individually.
cam specs
