Morel 7717 Drop-In Lifters

[all muSScle]

All,

I am in the process of rebuilding the LS3 out of 2013 Camaro SS and wanted to get some input regarding the Morel 7717 drop in replacement lifters. Here is a basic break down of the build:

-Balance and blueprint engine
-Stock bottom end w/ ARP hardware (main studs and ARP2000 rod bolts)
-New bearings (mains, rods, cam) and rings
-New GM Oil Pump and pickup tube w/ Improved Racing Pickup Tube Brace
-Cloyes Race Billet True Roller Timing Set w/ C5R Extreme Duty Chain
-BTR Timing Chain Dampener
-TSP Stage 2 N/A Cam (229/244, .629/.615, 112 LSA)
-PAC .660 Dual Valve Springs, Titanium Retainers, Viton Seals, New Seats and Locks
-CHE Trunnion Upgrade
-Morel 7717 Drop-In Lifters
-GM Lifter Trays
-All new gaskets and seals (Fel-pro and GM only)
-ARP Fasteners across the board

This is strictly being built as a fun, reliable street car but with the aggressive lobe profiles, high spring pressures, and RPM capabilities of the TSP cam I’m a little concerned about the reliability of the drop-in style lifters. The cam makes peak power at 6600 RPM per TSP and I don’t have any intention of reviving it much past that as this isn’t a race car but I want the peace of mind that it will handle it if I do want to romp on it. I chose the Morels as I have used them in the past on a couple of SBC builds and was very impressed with them (albeit they were link bar style) and they also seemed like an upgrade over the LS7 lifters that many folks use with cam swaps. However, the previous Morels that I purchased came in a nice sealed, foam tray whereas these came in a cardboard box with cardboard separators so I was a little shocked at that. I’m sure that has little relevance on the quality but it didn’t give me the warm, fuzzy feeling either. This car is not my daily driver and will be babied for the most part so I didn’t feel that I needed $1000 plus set of lifters for a build that won’t see anything past 6700-6800 RPM but wanted to get others opinions on the reliability of the drop-in style lifters, specifically the Morel 7717’s and see if these would be suitable for my application? Lastly, I know that proper pushrod length is key to setting the proper preload on the lifters and is a major factor in terms of longevity on the net lash style valve train and this will all be properly measured at the machine shop before ordering push rods.

Thanks in advance.

[acammer]

The 7717 is the replacement for the 6504 lifters, which are their no-frills LS7 OEM style lifter. These are more or less equivalent to the OEM LS7 style lifters that came stock on your LS3. So, not an upgrade, not a downgrade.

Dollar for value, the best lifter option for most street style builds are the Chevrolet Performance - Racing/GMPP "Caddy" lifters. These are outwardly the same dimension as the OEM LS7 lifter, but they are a higher material quality, higher build quality, and a superior check-ball internal mechanism. We've used these with spring pressures approaching 500lbs open and 8,000rpm combinations with good results. Presently they are only a whole $8 more than OEM LS7 lifters, and represent a very good value. Your "best" drop in option would be the Johnson 2110R, but those have gotten extremely pricy and wouldn't be my choice for most street combinations as they are overkill.

[Black_SS10]

Originally Posted by acammer

The 7717 is the replacement for the 6504 lifters, which are their no-frills LS7 OEM style lifter. These are more or less equivalent to the OEM LS7 style lifters that came stock on your LS3. So, not an upgrade, not a downgrade.

Dollar for value, the best lifter option for most street style builds are the Chevrolet Performance - Racing/GMPP "Caddy" lifters. These are outwardly the same dimension as the OEM LS7 lifter, but they are a higher material quality, higher build quality, and a superior check-ball internal mechanism. We've used these with spring pressures approaching 500lbs open and 8,000rpm combinations with good results. Presently they are only a whole $8 more than OEM LS7 lifters, and represent a very good value. Your "best" drop in option would be the Johnson 2110R, but those have gotten extremely pricy and wouldn't be my choice for most street combinations as they are overkill.

This.

[morepowerjoe]

Originally Posted by acammer

The 7717 is the replacement for the 6504 lifters, which are their no-frills LS7 OEM style lifter. These are more or less equivalent to the OEM LS7 style lifters that came stock on your LS3. So, not an upgrade, not a downgrade.

Dollar for value, the best lifter option for most street style builds are the Chevrolet Performance - Racing/GMPP "Caddy" lifters. These are outwardly the same dimension as the OEM LS7 lifter, but they are a higher material quality, higher build quality, and a superior check-ball internal mechanism. We've used these with spring pressures approaching 500lbs open and 8,000rpm combinations with good results. Presently they are only a whole $8 more than OEM LS7 lifters, and represent a very good value. Your "best" drop in option would be the Johnson 2110R, but those have gotten extremely pricy and wouldn't be my choice for most street combinations as they are overkill.

I just replaced my lifters from the gm performance lifters (ls7) good to 7k rpm to the gm performance racing versions that are good to 8k rpm just for piece of mind because I used to run up to 6700 rpm and didn't like getting that close to the 7k rpm limit on the gm performance ones. They actually quieted down the lifter tap quite a bit. That's also what we're pitting in my son's c5 ls1 rebuild now as well.

[1JEWLDSSRS]

Originally Posted by acammer

The 7717 is the replacement for the 6504 lifters, which are their no-frills LS7 OEM style lifter. These are more or less equivalent to the OEM LS7 style lifters that came stock on your LS3. So, not an upgrade, not a downgrade.

Dollar for value, the best lifter option for most street style builds are the Chevrolet Performance - Racing/GMPP "Caddy" lifters. These are outwardly the same dimension as the OEM LS7 lifter, but they are a higher material quality, higher build quality, and a superior check-ball internal mechanism. We've used these with spring pressures approaching 500lbs open and 8,000rpm combinations with good results. Presently they are only a whole $8 more than OEM LS7 lifters, and represent a very good value. Your "best" drop in option would be the Johnson 2110R, but those have gotten extremely pricy and wouldn't be my choice for most street combinations as they are overkill.

Great info as always acammer.. Thanks sir!! I have the Delphi LS7 lifters supposedly in mine, how do they rate in quality as I run mine up to 7200 all the time. Just don't want to have an issue if they are not quality lifters for that rpm range, Thanks

[acammer]

Originally Posted by 1JEWLDSSRS

Great info as always acammer.. Thanks sir!! I have the Delphi LS7 lifters supposedly in mine, how do they rate in quality as I run mine up to 7200 all the time. Just don't want to have an issue if they are not quality lifters for that rpm range, Thanks

I'm suspicious of the Delphi lifters to be honest - they don't seem to be the same quality as the oem GM LS7 lifter. Their pricing reflects that as well, there is no free lunch and a set of lifter that cost half that of the GM lifters should make a potential buyer ask some questions. 7200 is more than we like see even with a genuine GM LS7 lifter, especially when such a better lifter, the GMPP Caddy lifter, is nearly the same price.

[IKILLEDSUPERMAN_ZL1]

I went with the GM performance lifters for my new motor. #12499225.

[all muSScle]

Thanks everyone for the replies. Is this the correct part number for the GMPP Caddy Lifters (88958689)? I’ve read some mixed reviews over the years on these in that they were intended for ultra light valve trains and single valve springs and that more aggressive lobe profiles and stiffer springs have resulted in failures. I’m not sure how reliable these claims are but I also can’t seem to find their max force rating either. The PAC racing springs supplied from TSP have a spring rate of 392 lb/in (160 lb seat at 1.8” and 415 lb open at 1.15”), which would put me right at 407 lb at max lift on the intake (.629”). Can anyone confirm the max pressure on the Caddy Lifters and if they would tolerate 400+ lbs of force? Again, thanks for the replies thus far and not trying to muddy the waters but I want to make sure that I’m selecting the correct lifter for my application. Thanks in advance.

[acammer]

Originally Posted by all muSScle

Thanks everyone for the replies. Is this the correct part number for the GMPP Caddy Lifters (88958689)? I’ve read some mixed reviews over the years on these in that they were intended for ultra light valve trains and single valve springs and that more aggressive lobe profiles and stiffer springs have resulted in failures. I’m not sure how reliable these claims are but I also can’t seem to find their max force rating either. The PAC racing springs supplied from TSP have a spring rate of 392 lb/in (160 lb seat at 1.8” and 415 lb open at 1.15”), which would put me right at 407 lb at max lift on the intake (.629”). Can anyone confirm the max pressure on the Caddy Lifters and if they would tolerate 400+ lbs of force? Again, thanks for the replies thus far and not trying to muddy the waters but I want to make sure that I’m selecting the correct lifter for my application. Thanks in advance.

That's the right part number. Like I said in my original reply, we have used these with up to 500 pounds of open pressure with good results. It's true that these were originally set up with a fairly light beehive Spring, that was for a pure racing application that would spend all of its time over 6500 RPM, which is extremely far in excess of what even aggressively runs street engines will see. These are just fine for your combination, and are a great choice for the money.

[acammer]

It is also worth noting that your OEM valve train would be considered ultra light, you really can't get any lighter than the is the hollow stem GM intake valve and OEM rocker set up. It would be our recommended setup for 95% of Gen. 4 builds that are going to do 8000 or less RPM.

[all muSScle]

acammer,

Thanks for the reply and my apologies for missing the 500lb opening pressure comment in your original post! What is the recommended preload on them? Also, are these lifters the ones that have a groove around the circumference of the body?

[1JEWLDSSRS]

Originally Posted by acammer

I'm suspicious of the Delphi lifters to be honest - they don't seem to be the same quality as the oem GM LS7 lifter. Their pricing reflects that as well, there is no free lunch and a set of lifter that cost half that of the GM lifters should make a potential buyer ask some questions. 7200 is more than we like see even with a genuine GM LS7 lifter, especially when such a better lifter, the GMPP Caddy lifter, is nearly the same price.

Thanks acammer for your reply. Guess I need to be careful with these then. Now ya got me thinking about doing the caddy lifters, was looking at the Johnson's, but as you said, it is really overkill, plus I would need longer PR's for them. Appreciate your knowledge and sharing. Oh, and the only reason I pull it out to 7200 is the big LOD intake I have is still making power up there.

[Batmanntexas]

acammer, you sir, are the MAN!!!

[1JEWLDSSRS]

Originally Posted by Batmanntexas

acammer, you sir, are the MAN!!!

^^^^ totally concur!!! You don't see anyone else on here as dedicated to our quest as acammer!!! . And I for one, totally appreciate him AND his knowledge...