PRW Roller Rocker Issue

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Moparnutt340

Moparnutt340

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Location
SW Ont Canada
Looking for some feedback from experienced engine builders

A guy has a 360 built by a well known builder, for big bucks..........
The engine is broken in and dyno tuned before pick-up.........
Buyer puts it in his car and runs it for about 20 min when it begins to run ruff, fouls a plug, then stalls.
When trying to restar it backfires
Replaced the plugs, start it up and its ticking on #6
Pull the valve cover to find amongst all the 1.6 roller rockers there is 1 odd 1.5 rocker, guess where, #6 Intake
After closer look it turns out the lifter seat is jammed down or stuck. Is it just coincidence that its the one with the 1.5 rocker ?

Builder offers to supply new lifters and gaskets for the repair, but say the 1.5 rocker will not cause any issues, still use it when reassembling the engine.

Knowing that a 1.6 to a 1.5 rocker can change the cam lift by about 30%, I'm not comfortable with leaving that 1.5 in there. I'm told that cylinder will not make the same power as the rest ?

If you have the knowledge that I need, please voice your opinion on using the 1.5 rocker or replacing it with a 1.6

THANKS !
 
Well it actually makes about 7% difference in lift so it's not that much of a deal. No matter what 15 @ 1.6 and 1 @ 1.5 is wrong. The builder owes him a 1.6 rocker. There is a difference in pushrod clearance between 1.5 and 1.6 rockers.
 
IQ52 said:
There is a difference in pushrod clearance between 1.5 and 1.6 rockers.
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With that said, do you believe the 1.5 rocker would be the cause of that lifter getting jammed stuck down or is that more likely a defective lifter
 
I think the engine builder owes your friend a new lifter, proper length push rod and a 1.6 rocker arm. JMO
 
Demon416 said:
I think the engine builder owes your friend a new lifter, proper length push rod and a 1.6 rocker arm. JMO
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He is sending a set of lifters and top end gaskets, the pushrod is same one on all 16 so don't need that
The question is of the rocker.


iw378 said:
Take car back to engine builder and have HIM do the work.
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Engine builder is in U.S.A, car is in Canada....... Engine is in the car which is not quite finished restoration. It would be far more costly to pull engine and return it than to just simply change the parts at home


The builder has been good about sending the parts but i'm just questioning the fact that he says leaving the 1.5 rocker in there is ok.
I can't believe he is ok with that. My theory is that he is avoiding replacing the rocker because he can't buy a single rocker and to buy a whole new set is $300
 
Understand.....once you turn a wrench on that engine...engine builder is going to say ...anything new is your fault.....
 
If the builder supplied the rockers to the customer than by all means the customer is owed a 1.6 rocker. I'm thinking the builder used the same pushrod throughout. The long distance is a problem that I can understand being an issue. So you have to make the best out of what you have. In my opinion the 1.5 didn't cause the problem, you should look elsewhere.
 
SGBARRACUDA said:
If the builder supplied the rockers to the customer than by all means the customer is owed a 1.6 rocker. I'm thinking the builder used the same pushrod throughout. The long distance is a problem that I can understand being an issue. So you have to make the best out of what you have. In my opinion the 1.5 didn't cause the problem, you should look elsewhere.
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I spoke to the builder over the phone, he told me what to look for and he was right right from the start. Asked me to look at the lifter seat to see if it was down away from the retainer. it was...... He said this has happened before and its a defective lifter, not anything he has done. He told me to take it apart and he will send out the parts.

I will also add that when he said assemble it with the 1.5 rocker, I said I'm not comfortable doing that and I would like a 1.6 to replace it. He didn't say no, he just said he will see what he can do. I'm just trying to see what others opinion is on the fact that he wanted me to use it. Maybe I'm wrong but that sounds kinda crazy to mix rockers in a $12K engine
 
Well I don't understand using one 1.5 rocker? They don't cost that much to buy a new one?
It's not unheard of to use 1.5 on intake and 1.6 on exhaust to compensate for head flow, or even to use them in reverse for the same reason. But to use one 1.5? there is no reason. cheaping out, lazy or who knows what was going through the builders mind.
 
SGBARRACUDA said:
Well I don't understand using one 1.5 rocker? They don't cost that much to buy a new one?
It's not unheard of to use 1.5 on intake and 1.6 on exhaust to compensate for head flow, or even to use them in reverse for the same reason. But to use one 1.5? there is no reason. cheaping out, lazy or who knows what was going through the builders mind.
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He said that was a set right out of the package and he can't believe he overlooked it. He was very apologetic and said he will make it right as this is "still his motor" as he put it.

He did say in some builds he uses 1.5 / 1.6 but only on all 8 cyl, never on 1 only
 
Moparnutt340 said:
He said that was a set right out of the package and he can't believe he overlooked it. He was very apologetic and said he will make it right as this is "still his motor" as he put it.

He did say in some builds he uses 1.5 / 1.6 but only on all 8 cyl, never on 1 only
Click to expand...

That is good. He is right ,they probably were packaged that way. Glad to hear he is going to take care of the issue.
 
70aarcuda said:
Are they the stainless or aluminium rockers?
Click to expand...

Aluminum PQ series


Look like this pic

$_57.JPG
 
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