wrecked engine -- here's the damage
Thread Starter
6th Gear Member
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
my77: the 570 is currently in the trunk. Just re-jetted back to stock and changed gaskets
67m302: obviously I like the idea of roller cams. But I have not the foggiest idea of what work is involved, what parts to get. i've heard about a conversion kit (spider and dogbones) for which I'd have to drill/tap a few holes into the block?!
further i'll probably have to get different valve springs and stuff. this exceeds my knowledge about setting it up. I believe I'm already going all out with getting a pushrod length checker. I can change parts, but planning a new build is probably a bit over my head
and what camshaft would fit. I blieve I'll just put in another hyd flat tappet just for the sake it's easier. I've done two in the past, so I'm quite confident I can install them without lobes disappearing.
edit: well I checked on the price of roller lifters and boy that is not in budget 390£ here. that's more than a cam and lifter kit
67m302: obviously I like the idea of roller cams. But I have not the foggiest idea of what work is involved, what parts to get. i've heard about a conversion kit (spider and dogbones) for which I'd have to drill/tap a few holes into the block?!
further i'll probably have to get different valve springs and stuff. this exceeds my knowledge about setting it up. I believe I'm already going all out with getting a pushrod length checker. I can change parts, but planning a new build is probably a bit over my head
and what camshaft would fit. I blieve I'll just put in another hyd flat tappet just for the sake it's easier. I've done two in the past, so I'm quite confident I can install them without lobes disappearing.
edit: well I checked on the price of roller lifters and boy that is not in budget 390£ here. that's more than a cam and lifter kit
Last edited by kalli; Mar 8, 2010 at 08:28 AM.
6th Gear Member
Joined: Jan 2007
Posts: 5,469
From: AR
If it were me I would run it just like it is for a little bit to see if everything is "ok", then I would change out the cam. It will suck driving on the flat lobe, but it wont hurt anything.
A "retro-fit" roller cam kit (OEM spider & bones with a reduced base cam) will be a bit more affordable than going with a linked roller lifter setup.
A "retro-fit" roller cam kit (OEM spider & bones with a reduced base cam) will be a bit more affordable than going with a linked roller lifter setup.
Thread Starter
6th Gear Member
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
JMD .. i just looked at my bank account, started crying. no roller camshaft it is .. ;-)
was driving the car around for a bit and it drives exactly like before the bang (at least my lazy *** doens't feel any difference).
just haven't fully floored it yet. even I have feelings for that car .. *g*
gives me more confidence that it was always the case and probably explains why i was constantly looking for more HP ...
the engine wasn't new. they built it for a ford GT. they drove the car 1000miles south to france, raced it for a few laps in "les mans" and drove it back.
so maybe 3000 altogether
I have found the following information:
1966 289 stock engine uses 6.776" rods. that matches what i measured for the rods I'm currently using for #5 cylinder(that's what I pulled out of my old 289)
1971 302 stock engine uses 6.876" rods. that matches whay i measured for the pushrods that were in the engine (and still is for all the other cylinders).
i measured with a measuring tape and it's all within 0.5mm (0.04"). you can't get more accurate with that tape measurer
from what i know and read you will need to change/measure pushrod length when anything in the valvetrain changed
and the follwing parts (at least) are diffgerent to stock:
camshaft, rockers (i have roller rockers), heads!
so basically nothing is stock and stock pushrods were used. I am quite sure the length is wrong unless edelbrock engineered their head, cam and roller rockers (no idea where they are from) in such a way that it matches stock again ...
Maybe this caused the problems? I wouldn't rule it out ...
was driving the car around for a bit and it drives exactly like before the bang (at least my lazy *** doens't feel any difference).
just haven't fully floored it yet. even I have feelings for that car .. *g*
gives me more confidence that it was always the case and probably explains why i was constantly looking for more HP ...
the engine wasn't new. they built it for a ford GT. they drove the car 1000miles south to france, raced it for a few laps in "les mans" and drove it back.
so maybe 3000 altogether
I have found the following information:
1966 289 stock engine uses 6.776" rods. that matches what i measured for the rods I'm currently using for #5 cylinder(that's what I pulled out of my old 289)
1971 302 stock engine uses 6.876" rods. that matches whay i measured for the pushrods that were in the engine (and still is for all the other cylinders).
i measured with a measuring tape and it's all within 0.5mm (0.04"). you can't get more accurate with that tape measurer
from what i know and read you will need to change/measure pushrod length when anything in the valvetrain changed
and the follwing parts (at least) are diffgerent to stock:
camshaft, rockers (i have roller rockers), heads!
so basically nothing is stock and stock pushrods were used. I am quite sure the length is wrong unless edelbrock engineered their head, cam and roller rockers (no idea where they are from) in such a way that it matches stock again ...
Maybe this caused the problems? I wouldn't rule it out ...
Thread Starter
6th Gear Member
Joined: Oct 2006
Posts: 6,417
From: Cork, Ireland
thx james, I'm glad it didn't go as bad as I suspected. I thought I destroyed heads and/or bottom end.
anyway I did a _lot_ of reading last night about the theory of midlift and over-arcing/under-arcing. wrong pushrod size cannot cause this problem if the rockers are adjusted properly. however I finally understood on why it is so important to have the correct length (travel/angle/valve velocity). It cleared up all my misunderstandings.
So it should be realted to the options JMD mentioned:
- over-revving (i should be protected by rev-limiter at 6200)
- lifter pump-up
- valve float (the springs should be the stock for the edl rpm. as this head is rated to make max power 6500 with all their other top end parts used (which I do), I don't think that should be an issue)
So maybe it was the lifters ?! the engine was clearly not warm enough, so that probably added to it, or was the root cause (oiling etc)
well I gave this all a long thought and although I wanted to go for a nice compcam/lunati/crane I decided to shove a new set of the edelbrock rpm camshaft with lifters in there. It's dynomatched to the heads and intake. I don't think I won't find better ?!
anyway I did a _lot_ of reading last night about the theory of midlift and over-arcing/under-arcing. wrong pushrod size cannot cause this problem if the rockers are adjusted properly. however I finally understood on why it is so important to have the correct length (travel/angle/valve velocity). It cleared up all my misunderstandings.
So it should be realted to the options JMD mentioned:
- over-revving (i should be protected by rev-limiter at 6200)
- lifter pump-up
- valve float (the springs should be the stock for the edl rpm. as this head is rated to make max power 6500 with all their other top end parts used (which I do), I don't think that should be an issue)
So maybe it was the lifters ?! the engine was clearly not warm enough, so that probably added to it, or was the root cause (oiling etc)
well I gave this all a long thought and although I wanted to go for a nice compcam/lunati/crane I decided to shove a new set of the edelbrock rpm camshaft with lifters in there. It's dynomatched to the heads and intake. I don't think I won't find better ?!
Last edited by kalli; Mar 9, 2010 at 04:13 AM.
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