A little background:
About 4 years ago, my '88 C1500 with the 5.7L TBI engine started overheating on me. I found the head gaskets blown. I knew the swirl port heads and peanut cam were about useless so, I decided to "upgrade" to better parts while trying to keep it fairly cheap - yeah right!
I went with a stiffer flat tappet cam and bought the Summit Racing 162108 aluminum heads made for a direct TBI swap, since they were advertised as better flowing than Vortec heads. I added other upgrades but, they're not really germane to this thread. I did research going to a roller cam then but, it would have been ~$800 more plus, at the time, I didn't know my block had the bosses for one.
A few weeks ago, my engine started making tappet noise and just didn't sound right. We popped the valve covers off and found what looked like 2 collapsed lifters. We set their "lash" at ~0.008" and buttoned it up. Took it for a drive to the parts house to get a PCV vacuum line and check it out. If it sounded OK, we were going to pull the intake manifold and swap/clean out the lifters. Well, it sounded OK going but, on the return ride, it started sounding bad and lost some power. That's when I decided to tear it down and go roller, like I should have done in the 1st place. After more research, talking to Summit Racing and Comp Cams Tech support I put a plan together.
The Summit Racing heads will only support ~.520" lift up to ~5,000 RPM. I went with the Comp Cams CL08-430-8 cam and lifter kit, .525/.525", 224/224 @ 0.050" and 986-16 springs (rated up to .540" lift), as recommended by Comp Cams. Then I had to get locators (bottom washer) and keepers (top washer) for their larger diameter, 1.43" instead of 1.25", installation kit (with spider, cam plate, dog bones, and bolts), locks, seals, 1.5 full roller rockers, push rods, etc. The roller cam takes a different timing gear and sprocket than a flat tappet cam so, I got a Trick Flow set with a thrust bearing in it. We're still working on it and I'll keep updating as we go.
The 1st thing I wanted to do was get a couple springs installed so we can get the proper length push rod.
Here's the difference between the original and new springs. The originals are a single spring with a damper (flat spring), on the left, while the new ones are dual springs with a damper. The originals have a seat pressure of 110 LB @ 1.780" while the new ones are 132 LB at 1.750" (even though they're taller unsprung. I got a shim package to get the 1.750" height.
Here's the difference between the Trick Flow timing set compared the the Cloyes Flat Tappet set. Note the smaller bolt circle on the Roller Cam set, plus the chain is beefier. Remember I'm not running a crank sensor so it'll fit under the OE timing cover.
Old cam vs new.
New cam going in, we were able to swing the condenser out a little to get the cams out and in.
Push rod length checker, I went with 7.25" Chromoly rods.
We started installing the springs and found the 2 middle ones for the exhaust valves wouldn't go down all the way! Even though Summit Racing says the seats on the heads are 1.550" and I ordered 1.500" locators, these 2 seats are closer to 1.44" and the head bolt washer between them sticks out to where I had to grind down the locators and flat spot them to fit.
Needless to say, we didn't get them done before it was time for cocktail hour and dinner at our favorite Tin Top Bar and Grill.
More to come...
As usual, all questions and comments are welcome!
About 4 years ago, my '88 C1500 with the 5.7L TBI engine started overheating on me. I found the head gaskets blown. I knew the swirl port heads and peanut cam were about useless so, I decided to "upgrade" to better parts while trying to keep it fairly cheap - yeah right!
I went with a stiffer flat tappet cam and bought the Summit Racing 162108 aluminum heads made for a direct TBI swap, since they were advertised as better flowing than Vortec heads. I added other upgrades but, they're not really germane to this thread. I did research going to a roller cam then but, it would have been ~$800 more plus, at the time, I didn't know my block had the bosses for one.A few weeks ago, my engine started making tappet noise and just didn't sound right. We popped the valve covers off and found what looked like 2 collapsed lifters. We set their "lash" at ~0.008" and buttoned it up. Took it for a drive to the parts house to get a PCV vacuum line and check it out. If it sounded OK, we were going to pull the intake manifold and swap/clean out the lifters. Well, it sounded OK going but, on the return ride, it started sounding bad and lost some power. That's when I decided to tear it down and go roller, like I should have done in the 1st place.
After more research, talking to Summit Racing and Comp Cams Tech support I put a plan together.The Summit Racing heads will only support ~.520" lift up to ~5,000 RPM. I went with the Comp Cams CL08-430-8 cam and lifter kit, .525/.525", 224/224 @ 0.050" and 986-16 springs (rated up to .540" lift), as recommended by Comp Cams. Then I had to get locators (bottom washer) and keepers (top washer) for their larger diameter, 1.43" instead of 1.25", installation kit (with spider, cam plate, dog bones, and bolts), locks, seals, 1.5 full roller rockers, push rods, etc. The roller cam takes a different timing gear and sprocket than a flat tappet cam so, I got a Trick Flow set with a thrust bearing in it. We're still working on it and I'll keep updating as we go.
The 1st thing I wanted to do was get a couple springs installed so we can get the proper length push rod.
Here's the difference between the original and new springs. The originals are a single spring with a damper (flat spring), on the left, while the new ones are dual springs with a damper. The originals have a seat pressure of 110 LB @ 1.780" while the new ones are 132 LB at 1.750" (even though they're taller unsprung. I got a shim package to get the 1.750" height.
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Here's the difference between the Trick Flow timing set compared the the Cloyes Flat Tappet set. Note the smaller bolt circle on the Roller Cam set, plus the chain is beefier. Remember I'm not running a crank sensor so it'll fit under the OE timing cover.
You must be registered for see images attach
Old cam vs new.
You must be registered for see images attach
New cam going in, we were able to swing the condenser out a little to get the cams out and in.
You must be registered for see images attach
Push rod length checker, I went with 7.25" Chromoly rods.
You must be registered for see images attach
We started installing the springs and found the 2 middle ones for the exhaust valves wouldn't go down all the way! Even though Summit Racing says the seats on the heads are 1.550" and I ordered 1.500" locators, these 2 seats are closer to 1.44" and the head bolt washer between them sticks out to where I had to grind down the locators and flat spot them to fit.
Needless to say, we didn't get them done before it was time for cocktail hour and dinner at our favorite Tin Top Bar and Grill.
More to come...As usual, all questions and comments are welcome!
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