|
#1
|
||||
|
||||
engine breakin
hey guys, so i called my valvetrain company huges engines and asked Dave about installing lifters pumped up or not and breaking in the motor and blah blah blah. all sounded pretty easy till he mentioned the possiblility of the lifters pumping up and maybe smashing into the pistons!! oh god... see i'm using hydraulic lifters and adjustable rocker arms with dome pistons... anyone else doing and engine this silly? if so how did it work for you and if not how can i see to a good breakin and engine life without pulling the heads back off the check clearances and such?
|
#2
|
|||
|
|||
Clearances
When you , or whomever built your engine, the valve clearance should have been addressed at that time. Piston dome height determines maximum valve lift. When assembling the heads, the pushrod length should have been determined with a solid lifter of the same length as your hydraulics when pumped up. At that time, the rocker adjusters should have been set.
It sounds like theses issues are not addressed, and I suggest that you might want to talk with all parties involved before even cranking the engine over manually. Even head gasket thickness should have been considered. |
#3
|
|||
|
|||
Quote:
|
#4
|
||||
|
||||
Usually valve to piston clearence is checked with clay on the piston then putting the head on with a gasket, adjust the valves and crank the engine over. Then pull the head and check how much the valves smashed the clay. You want a min. of 0.100".
I made the mistake of not checking this clearence on and engine that I built. The pistons were advertised in Summit as "large valve reliefs for high lift cams", Lift was only 0.450". I let it go and ended up with a $600 set of pistons that had valves sticking out of them. I checked the part number on JE's website and the pistons had shallow valve reliefs for maximum compression. Check it, it cost way too much to fix. |
#5
|
||||
|
||||
engine
yea, i'm the one building the engine, i did use an adjustable solid lifter and adj. pushrod and mock up my valvetrain to have pushrods cut to length and didnt have a problem then, but i see where your saying also how long the valve is open, these are the things i am worried about because also i dont want to make the expensive mistake....when its done i'll have about $7000 in this motor i've been building since highschool so i dont wanna do it again!
|
#6
|
||||
|
||||
Trust me it's just as expensive the second time. Head gaskets are pretty cheap.
When I blew mine up I even wrecked the heads put the valves right through them. Makes it even more expensive. |
#7
|
|||
|
|||
Best laid plans..........
Can be for naught. Haven't done it lately but will soon. When using Hyd. lifts and adj. rockers, I always pump up the lifters before install. Then I adjust the rockers to about .030 clearance before start so they will rattle on start. Yes this is less pinpoint but always worked for me. After start adjusting the rattle out and then 1/4 turn more for pre-load while taking an oil bath.
I'm sure most of you are laughing at me right now but I've never had a problem but I always check my valve clearance with clay while building the engine. But I'm always open to better ways of thinking. |
#8
|
|||
|
|||
Pumping up the lifters before installation with a non-adjustable valve train is always risky. If you install the lifters dry and do a correct and thorough pre-lube the lifters fill to their normal running height during the pre-lube.
|
#9
|
||||
|
||||
gaskets
well i was told i could pump up the lifters one to to pumps max then set my valve tip clearance....if i pull the heads can i reuse the gaskets? or once they have been compressed is that it?
|
#10
|
|||
|
|||
Some may disagree with me, but my boss has been building engines for a long time and has reused head gaskets if they have not been run on the engine. If they are felpro and they don't stick and peal he has had no problems. Its up to you I guess.
|
#11
|
|||
|
|||
I agree with this.
|
#12
|
|||
|
|||
I would never............
Try to run a head gasket I had re-torqued to full torque. When checking for clearance, I torque to 10/20 lbs to fit the head to the block and then check for clearance. Depending on the type of gasket used, you know what clearence you have. If you don't trust this then you should replace the gaskets with the exact gaskets.
Gasket have a compression built into them to seal the pressures within. When you void the intended use you have nothing of what was designed. Sorry, just thinking out loud. |
#13
|
|||
|
|||
The gasket compression thickness is noted somewhere. Why not just do the clearance test and subtract the difference? Works for me!
|
#14
|
||||
|
||||
I have to agree. I wouldn't run a gasket that's been crushed. They have a designed amount of crush in the gasket to help get it to seal.
But I have seen it done without a problem. Your not supposed to reuse bearings either as they have a designed amount of crush in them too, but I have reused them if good and haven't had any problems. |
#15
|
|||
|
|||
Jvmopar..............
I agree. If the amount of compression of the gaskets doesn't exceed the amount of compression designed by the manufacture of the gaskets, then there is no problem as the gaskets will continue to compress to the designed thickness. If you expect the gasket to hold after it has reached it's planned pressure, you need to look at the process again. If the experts tell you that 345 lbs of punch will knock a man out and you try it and it don't work???????? Then don't expect it to work the next time. Just as in humans, there are times that something doesn't work for the same ole same ole. I knew a guy that got hit in the side of the head with a baseball bat and he blinked and told the other guy, Don't do that again or I'll kick your ass. This is a point that I would run.
Truth is that what happens one time doesn't happen in like events. Sometimes it is the little events that cause a different outcome. I remember a 352 ford smoking a 406 ford with everything else equal. You can't account for small differences. I've seen 440's that seemed equal, that one beat the other like it was a step-child. NASCAR gets 800 hp from small blocks that most of us can't get 650 hp from. |
#16
|
|||
|
|||
After checking clearances, fill the lifters and assemble everything.
Then rotate the motor 1/4 turn and wait a half hour and repeat. Do this 8 times, it is ready to start. |
#17
|
||||
|
||||
Why not just prime the engine with a drill...and after it got good oil pressure running thru it for about a minute, rotate the engine over by hand? If they are going to hit, you will feel it and it will not ruin pistons or valves. My cam company says to put assy lube on the lifters, install, and prelube the engine! Not fill the lifters.
|
#18
|
||||
|
||||
lifters
i did call huges engines on this and they said lube the lifters and intsall. i can he said pump the lifters up as much as 2 pumps but thats it. i also need to set my valve lash before i break it in, i can acctually see thru the spark plug hole that the valve is pretty far from the piston....exact measurment i'm not sure .100 or maybe more, just looking i'd say i'm covered but i'm going to assemble the thing rotate it by hand and make sure it wont hit and look in there also and see that i'll have enough clearance, if it looks too close i'll pull the heads off and recheck it.
|
#19
|
||||
|
||||
The reason for checking is you need 0.100" clearence because things expand as they get hot, and your connecting rod actually stretches out the higher RPM you go. Aluminum rods fatiuge after a certain amount of use because of this streching and returning. So if you only have 0.001" clearence cold and by hand it won't hit but hot at 5000 rpm it will hit.
I did it to a $8000 motor and spent $3000 to fix it. stupid for 30 minutes of work. Infact if you look at the current mopar muscle mag they show a guy in their engine challange that is playing on the edge of this. The numbers on the top of the piston are transfered to the head. They say it's just tight clearences, but I think it's actually hitting near the upper RPM limit. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
whats the most horse power you could have for a 23 splind 4 speed with out breakin it | 73_RoadRunner | Performance Talk | 12 | 06-28-2003 01:30 AM |
Hydraulic Cam Breakin Proceedure | cuda66273 | Engines | 10 | 10-27-2002 10:33 AM |
Rebuilt Engine Breakin | cudacarl | Performance Talk | 2 | 02-10-2002 11:40 AM |
New Engine Breakin????? | kmounteer | Ram Truck Chat | 2 | 07-05-2001 04:41 PM |
engine breakin | 67 plymouth | Performance Talk | 4 | 07-29-2000 05:45 AM |