Need help/ ideas on cam install

[detroitfan]

Looking for some help here...Hopefully I just did something stupid and I can fix it really easily.

I have installed a mast ss cam, btr trunion upgrade, and psc bee hive springs. I installed rockers on two driver side cylinders to verify pushrod length. I torque to 22 ft lbs, and then manual turned the engine over.

I can feel resistance and a faint tap on exhaust valve...so I think I have a clearance issue. Can you think of what I might have done wrong?

This is my first time, and have followed the diy sections, but really baffled and praying it isn't that the cam is too aggressive..ill be calling Mast tomorrow, but thought id throw it out there for any one online during Mothers day.

Thanks!

[Soybeanrice]

Post the cam specs and the length of the pushrods you're using.

[detroitfan]

Lsa 112, 9.5 overlap
Intake centerline 116 duration230.5 lift .60966
Exhaust centerline 108 duration 237.2 lift .61588

It also says camshaft data at -4 degrees

This is from the card it came with, using stock pushrods to test with right now.

I talked to an engine builder at Mast and he said install dot to dot..thanks!

[christianchevell]

Not many use single bee hives for a larger lift cam as they are weaker therefore more forgiving for higher revs and longevity versus the ability to be able have strength for the amount dual springs have especially in other areas. So beehives usually means lower lift form what I read up on when getting my springs and Pushrods are determined via the base circle of the cam and a pushrod measurement ..... The manufacturer should be able to tell you the average pushrod used based on their base circle, though I think most of masts cams were not the highest in lift in their various stages.

If you had the heads off and then back on you could mock up with clay, and for one you better make sure you have the cam in the right position as that could cause a instant grenade and would not be the first I have heard of where a improperly timed cam ate a engine. If the cam comes with + or - symbols the installation of the cam must be advanced or retarded that amount with the timing wheel to verify . Good Luck. For instance my current cam came 114+4 do you think my tuner installed it with plus four degrees........

Advancing and Retarding:

By advancing the cam, the valves open and close earlier. Duration and overlap remain unchanged. Advancing raises the cylinder pressure (due to earlier valve closing) This improves low end and mid-range torque at the expense of some top-end power. The result is similar to using a shorter-duration cam since the intake valve closing point is more critical than its opening point.

Retarding the cam so valves open and close later has the opposite effect. This should increase top-end power, at the expense of low end, and mid-range torque. Thus: 1) Advance Cam: More low and mid-range torque, 2) Retard Cam: More top-end power.

Advancing and retarding are easily accomplished with offset bushings or keys for the cam or crankshaft, depending on the engine. The bushings and keys are usually supplied in increments of 2, 4, 6, and 8 crankshaft degrees. Remember that one crankshaft degree equals two camshaft degrees.

[detroitfan]

Thanks, springs and cam came together from mast so I was trusting them. There is a little more to the Story as I didn't receive the cam I ordered, I ordered one with less overlap and shorter duration....so when I received this I talked to one of their engine builder and he assured me if be ok. I definitely don't want to grenade my motor, just thought maybe something simple I missed

[15rs/ss]

They sent a different cam than you ordered?

[DOC52]

OP, they might assure you but you have a different cam than you ordered, seems fishy to me.

[detroitfan]

I don't think it's fishy, they have two of the shelf grind for ls3s...They sent the one that is more aggressive...that's all...probably a mistake, but I decided to go for it...They build some nice motors, I'll give an update after I talk to them

[DOC52]

Originally Posted by detroitfan

I don't think it's fishy, they have two of the shelf grind for ls3s...They sent the one that is more aggressive...that's all...probably a mistake, but I decided to go for it...They build some nice motors, I'll give an update after I talk to them

Wouldn't trust a shop that sent me the wrong part but that's just the way I think. Hope it works out.

[bionick]

Get dual springs. I'm running BTR platinum .660. Do some research on here, you don't want a cam that aggressive with singles

[Badfinger]

Originally Posted by bionick

Get dual springs. I'm running BTR platinum .660. Do some research on here, you don't want a cam that aggressive with singles

+1

[detroitfan]

Thanks for the feedback, I talked with Mast today, they were really supportive and assured me that the cam would not gavhave any issues....so I pulled the cam gear of to look more and embarrassingly realized I didn't have the cam pin in the hole...I swore it was lined up...but I guess not...can't believe I did that...

[Soybeanrice]

Originally Posted by detroitfan

Thanks for the feedback, I talked with Mast today, they were really supportive and assured me that the cam would not gavhave any issues....so I pulled the cam gear of to look more and embarrassingly realized I didn't have the cam pin in the hole...I swore it was lined up...but I guess not...can't believe I did that...

Close one. Glad you caught it now

[Synner]

A dual spring doesn't stop PTV clearance problems, no spring will. The spring has nothing to do with noise when rotating the motor. Measure PTV clearance.