Waking Up a Turd
Hello All,
Im a noob to this forum, but have been lurking for a while. Im general impressed with the vast amount of knowledge around with the LA engines. Im hoping you all can point me in the right direction with my turd of a 360.
A long time ago i acquired someone else's project, that they lost interest in. Its a 84 D150 shortbox.
I know, I know, 2 strikes already, A noob, AND a truck! Please hear me out!!!!!! It will get better, i promise.
This truck was built with a 318, 904, and 8 1/4 combo, and was on propane! yuk!
It now has a 360, with a 727, and an 8 3/4. Its warmed up nicely, But the package is still slow. I was hoping to get pointed in the correct direction by some small block experts.
My main focus, is that this whole package is slower than the 79 Little Red Express Truck 1/4 mile specs, that Alpar lists on their site "15.71 seconds @ 88 MPH" I made it to the local strip, on a Friday Street Legal Fun Night, and wound up with a consistent 16.4
As stated, I picked up someone elses project, And thus im not too sure exactly whats in it. This i do know. The engine is a 79 casting, The heads are 915 J heads. It has an Offenhouser Dual Port intake (340 square bore version). Topped with an Edelbrock 650 carb.
The previous owner said it was built with "10-1 flat tops" and "the second biggest Mopar Purple shaft cam"
My digging into cam specs would let me think the cam is the specs listed below.
PRODUCT DESCRIPTION
Fits: Small Block, Advertised Duration 284/284, Lift .484/.484
Camshaft, Hydraulic Flat Tappet, Advertised Duration 284/284, Lift .484/.484, Chrysler, 273, 318, 340, 360
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 2,600-6,000
Intake Duration at 050 inch Lift: 241
Exhaust Duration at 050 inch Lift: 241
Duration at 050 inch Lift: 241 int./241 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 284
Advertised Duration: 284 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.484 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.484 in.
Valve Lift with Factory Rocker Arm Ratio: 0.484 int./0.484 exh.
Lobe Separation (degrees): 108
I use this truck as a summer driver, and will occasional take it to the strip. This winter, i think i will pull out the engine, and check it over. I want to ensure that the bottom end is sound, and make some changes as required to make it faster than a little red truck.
I know that the intake manifold is mismatched to the cam, and plan on replacing it.
With those details out of the way, i can ask some questions:
What would the recommended cylinder head be for this type of combo? If you subscribe to the Engine Masters basic recommendations, "Buy the best head you can afford" motto, I am wondering if i would be better off with trying to source a later swirl port head, and having them rebuilt (likely about $1000 or more with 2.02 valves) or going with a Indy LA-X or Edelbrock performer head? Machine work is very expensive in my area. The cost of machining would narrow the difference down substantially, making the LA-X head quite interesting to me. Actually more specifically im interested in the INDY/IMM SB Mopar Heads.
Since this will be a mostly street driven unit, At what point does the larger port volume start to affect drive-ability?
Is this camshaft even big enough to fully make use of an aftermarket head? or would i be better off to try to port the old J heads myself?
What kind of cranking pressure should i have if this engine truly had 10-1 compression?
And finally Intakes...... Is the edelbrrock performer or performer RPM a better choice for this heaver vehicle? Is there a vintage made dual plane manifold that would be a good choice? I have really begun to dig the older "Just stepped out of the 90's" look of this truck. and for that reason, i thought i would try keep the offy intake, but it is a hindrance.
Im going to put up another post in drive trains to help me identify, and choose a proper stall converter for this unit
Hello All,
Im a noob to this forum, but have been lurking for a while. Im general impressed with the vast amount of knowledge around with the LA engines. Im hoping you all can point me in the right direction with my turd of a 360.
A long time ago i acquired someone else's project, that they lost interest in. Its a 84 D150 shortbox.
I know, I know, 2 strikes already, A noob, AND a truck! Please hear me out!!!!!! It will get better, i promise.
This truck was built with a 318, 904, and 8 1/4 combo, and was on propane! yuk!
It now has a 360, with a 727, and an 8 3/4. Its warmed up nicely, But the package is still slow. I was hoping to get pointed in the correct direction by some small block experts.
My main focus, is that this whole package is slower than the 79 Little Red Express Truck 1/4 mile specs, that Alpar lists on their site "15.71 seconds @ 88 MPH" I made it to the local strip, on a Friday Street Legal Fun Night, and wound up with a consistent 16.4
As stated, I picked up someone elses project, And thus im not too sure exactly whats in it. This i do know. The engine is a 79 casting, The heads are 915 J heads. It has an Offenhouser Dual Port intake (340 square bore version). Topped with an Edelbrock 650 carb.
The previous owner said it was built with "10-1 flat tops" and "the second biggest Mopar Purple shaft cam"
My digging into cam specs would let me think the cam is the specs listed below.
PRODUCT DESCRIPTION
Fits: Small Block, Advertised Duration 284/284, Lift .484/.484
Camshaft, Hydraulic Flat Tappet, Advertised Duration 284/284, Lift .484/.484, Chrysler, 273, 318, 340, 360
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 2,600-6,000
Intake Duration at 050 inch Lift: 241
Exhaust Duration at 050 inch Lift: 241
Duration at 050 inch Lift: 241 int./241 exh.
Advertised Intake Duration: 284
Advertised Exhaust Duration: 284
Advertised Duration: 284 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.484 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.484 in.
Valve Lift with Factory Rocker Arm Ratio: 0.484 int./0.484 exh.
Lobe Separation (degrees): 108
I use this truck as a summer driver, and will occasional take it to the strip. This winter, i think i will pull out the engine, and check it over. I want to ensure that the bottom end is sound, and make some changes as required to make it faster than a little red truck.
I know that the intake manifold is mismatched to the cam, and plan on replacing it.
With those details out of the way, i can ask some questions:
What would the recommended cylinder head be for this type of combo? If you subscribe to the Engine Masters basic recommendations, "Buy the best head you can afford" motto, I am wondering if i would be better off with trying to source a later swirl port head, and having them rebuilt (likely about $1000 or more with 2.02 valves) or going with a Indy LA-X or Edelbrock performer head? Machine work is very expensive in my area. The cost of machining would narrow the difference down substantially, making the LA-X head quite interesting to me. Actually more specifically im interested in the INDY/IMM SB Mopar Heads.
Since this will be a mostly street driven unit, At what point does the larger port volume start to affect drive-ability?
Is this camshaft even big enough to fully make use of an aftermarket head? or would i be better off to try to port the old J heads myself?
What kind of cranking pressure should i have if this engine truly had 10-1 compression?
And finally Intakes...... Is the edelbrrock performer or performer RPM a better choice for this heaver vehicle? Is there a vintage made dual plane manifold that would be a good choice? I have really begun to dig the older "Just stepped out of the 90's" look of this truck. and for that reason, i thought i would try keep the offy intake, but it is a hindrance.
Im going to put up another post in drive trains to help me identify, and choose a proper stall converter for this unit