Bent push rods

[Heckler]

Give him a chance to fix them.....I think that the cause going by the vote seems to be probably due to the valves sticking and not closing allowing the pushrods to get out of position in their tappet cups etc which could cause the valve to be driven into the piston this then bends the pushrod or in the case of some volvo engines breaks the push rod...SOmetimes the valve gets off relatively unscathed.

I dont think the valves have moved in this case.
Stu

 

[Fire99]

Well I was going to throw in the Flux Capacitor into the equation since i've heard that can be a source of trouble especially in 1954. Oh hang on this isn't the Delorean Time Machine thread.

Well 50p is on the Stuck Valve Theory. I hope the OP will divulge the result to us when he's found the cause.

 

[VicS]

Aha, the lifters will be hydraulic in both cases, they fill with the pressurised engine oil when it starts

I find it hard to believe.
Hydraulic lifters are surely intricate devices with several moving parts, springs balls etc and presumably made to a high precision.
These Mercruiser lifters only cost $7. No way are you going to get a hydraulic lifter for $7. Lucky to get a solid bit of metal for that price!

Sorry dont believe they are hydraulic.

 

[Bilgediver]

I dont think the valves have moved in this case.
Stu

I can understand you thinking this however I have seen a couple of instances on Yanmars and Volvos where the valves though stuck would open but the springs had trouble closing them . In fact the last Volvo I saw with this there was no proof the valves had stuck as they seemed fine as were the springs but the engine broke both push rods on the same cylinder.

 

[Heckler]

I find it hard to believe.
Hydraulic lifters are surely intricate devices with several moving parts, springs balls etc and presumably made to a high precision.
These Mercruiser lifters only cost $7. No way are you going to get a hydraulic lifter for $7. Lucky to get a solid bit of metal for that price!

Sorry dont believe they are hydraulic.

Vic
trust me, ive changed enough of them, they work by being fed by engine oil from the main oil pump/oil galleries, they go slack when the engine is stopped, the oil pumps them up on start up and there is enough pressure to keep the rockers tight on the valves. See here Thomas, oops! sorry Vic! http://en.wikipedia.org/wiki/Hydraulic_tappet
Stu

 

[VicS]

trust me, ive changed enough of them

You may have done but at 7 bucks a piece these ones cannot be hydraulic.

For a similar Volvo V8 they are 119 Euros ... I'll believe those are hydraulic.


And yes I have seen what Wikipedia says and several other more informative sources.

 

[trying]

VicS

As correctly stated, both types of lifter are hydraulic, that $7 would probably be for the flat hydraulic lifter. The roller hydraulic lifters are more expensive, from memory about three times the price of the flat type.

I can only think that 119 euros would be for a set of flat hydraulic lifters. There is no way that that would be each (no matter what type) because that would mean an engine set would then cost 1904 euros!!!!

 

[Heckler]

You may have done but at 7 bucks a piece these ones cannot be hydraulic.

For a similar Volvo V8 they are 119 Euros ... I'll believe those are hydraulic.


And yes I have seen what Wikipedia says and several other more informative sources.

Vic
stop getting arsy, I am being nice, just for once believe that someone else does know what they are talking about. I will defer to your electrical knowledge BUT my knowledge of how engines are put together and how they work is pretty comprehensive.
Stu

 

[tr7v8]

Vic
stop getting arsy, I am being nice, just for once believe that someone else does know what they are talking about. I will defer to your electrical knowledge BUT my knowledge of how engines are put together and how they work is pretty comprehensive.
Stu

I quite agree Stu. The Chevy has been made in numbers that most boat engine manufacturers only dream about & the Ford can't be a whole lot less.
A quick google gives 90,000,000 so that is why bits are cheap.
Wiki states "Finally superseded by GM's Generation II LT and Generation III V8 in the early 2000s and discontinued in 2004, the engine is still made by a GM subsidiary in Mexico as an aftermarket replacement. In all, over 90,000,000 small-blocks have been built in carbureted and fuel injected forms since 1955."
Don't quote rip off Volvo prices as they'll be hugely marked up. I think I only paid around 40 quid for a set of Rover V8 ones when I rebuilt that. Follow this link & it'll take you to Chevy race hydraulic followers for $82 a set of 16 which is a shade over 5 bucks a piece. http://tinyurl.com/lysc3e
and the link I posted to Real Steel where they are 50 quid or so a set.

Roller lifters are not hugely more expensive but only used with much more race orientated cams & builds & assuming this isn't a drag boat wouldn't be used in a normal soft tune boat engine.