To charley and frank: my original reply said “or early exhaust valve opening” but I couldn’t justify it other than because NOHOME questioned cam timing. Valves adjusted too tight would explain low cranking compression and glowing headers and sluggish revs and low vacuum. Good thinking, and a really inexpensive thing to test.
I’d back off all the rockers, or shim the pedestals if they’re shaft mounted. I don’t know SBF.
AngryCorvair said:To charley and frank: my original reply said “or early exhaust valve opening” but I couldn’t justify it other than because NOHOME questioned cam timing. Valves adjusted too tight would explain low cranking compression and glowing headers and sluggish revs and low vacuum. Good thinking, and a really inexpensive thing to test.
I’d back off all the rockers, or shim the pedestals if they’re shaft mounted. I don’t know SBF.
And that's an excellent response for the 100th page!
Charley
In reply to AngryCorvair :
Lifters checked.
What is frustrating is that I put this engine together with a friend who has done maybe a hundred 302 builds, so it is not like there should be a lot he has not seen. Yet here we are.
Maybe rummage in his parts stash and see if we can find an exploder cam to swap out the E cam. Might be worth changing the manifold to a single plane if that is an option.
Pete
Pete
In reply to NOHOME :
Loosen up the rockers again. It won’t hurt anything to let them clatter for a minute while you make a few test revs. If they’re not clattering, loosen ‘em some more. It’s the only way be sure you can eliminate that factor.
Lean mixture can also contribute to excess heat in the headers...clearly something(s) off if glowing at idle.
Vacuum leak, causing lean mixture?
Is it possible one or several valve guides are too tight and slowing the closing motion of exhaust valves?
If push really comes to shove and this starts to drive you crazy, there's always decent condition 5.0's with GT-40P heads waiting in yards for $500ish, just to get beyond this issue and on to the next aspect of the project to complete.
In reply to pres589 (djronnebaum) :
I actually have a backup 302 in another Volvo. Seems to run fine with factory EFI. Thing is if I pull that, no challenge car for me!
Pete
... you have a 5.0 Volvo going to the Challenge? Did I miss a memo?
Just get more V8's!
In reply to pres589 (djronnebaum) :
Why yes I do and the challenge is a bucket list item, so I had hopes this would be the car.
I accidentally bought it as a converted car. Conversion was done by an outfit called "Converse" or at least it used one of their kits. Came with hail damage and a host of electrical gremlins that made it Challenge priced.
Gave the roof a 20 ft paint job to get rid of the rust, dont really care about hail damage. Roof might be painted with a Swedish flag by October.
Fancy new grill cause we drink a lot of beer so that bad ideas seem good...plus I have an acre of this stuff to get rid of.
It has to deliver 3 people to the Challenge and complete the game. It does not have to come home as far as I am concerned, but it would be cool if it does.
In reply to NOHOME :
You ought to have a shot at the longest drive trophy.
In reply to DeadSkunk (Warren) :
Gotta find some places to stop along the way, myself, this would be a nice short 17 hour drive...crew wants a tour of the USA on the way down at least.
Pete
Looks like down I75 through Knoxville, TN - take short detour over the Hwy 129 -- and visit the "Tail of the Dragon" -- https://tailofthedragon.com/details/
I lived in Knoxville for 10 years -- many, many Saturday mornings on the motorcycle on Hwy 129 before it became the destination it is now. Great 11 mile stretch of road, 318 turns.
Todays party ended here:
Cam was installed just fine. It is an e-cam with all lobes present and accounted for and in spec lift-wise.
The lifters were not too tight.
Know for a fact that the pistons are flat-top with a zero deck height.
Next step is to do a hillbilly leakdown test and pump about 60 psi into each cylinder and see if there is leakage out the valves. After that, I got nothing.
There is an exploder cam lurking under a bench, but unless I can find a smoking gun, I am reluctant to re-assemble this lump.
Pete
In reply to NOHOME :
Timing chain, Isn't there a difference between the traditional 289/302 vs 5.0? That would cause an issue and I'm pretty sure that's a real thing that I'm not making up.
Well, there’s your problem right there. All the lifters are zip-tied.
bigfranks84 said:In reply to NOHOME :
Isn't there a difference between the traditional 289/302 vs 5.0?
Firing order is different - that was covered up above...I think nohome confirmed he had the correct firiing order.
New or used balancer? If used, did you confirm that the outer ring hasn't slipped? Did you check valve events with degree wheel or just confirm "dot to dot"?
In reply to MichaelYount :
I meant the actual timing chain parts, I know the firing order is.
In reply to MichaelYount :
New balancer and the cam was dot to dot.
Flumoxed because the symptoms suggest a smoking gun should be found.
One unknown at this point is the cam is an e-bay buy that I have no history on. Might have been ground defective for all I know. Good argument for degreeing in a cam when this goes back together. Regardless e-cam is out of the game and exploder cam is going back in whatever gets bolted together.
Pete
In reply to NOHOME :
Someone else earlier mentioned sticky valve guides. If the cam does not fix it pull the heads and check them.
In reply to TurnerX19 :
That might happen regardless. While everything is under suspicion, any aberant valve events woul have made for a non-steady vacuum signal.
Is there any event where the hydraulic lifters could "pump up" and keep the valves open to some degree? Cause that is what it feels like. And if it did happen, would there not be some erratic running behavior?
Pete
Could possibly be valve float? Somehow you got sent and installed the wrong valve springs?
It's a bit late now but I was wondering if this video is of any help? Not sure which FiTech model you have but thought this was good information since you mentioned early on documentation was a bit challenging.
https://www.facebook.com/fitechefi/videos/vacuum-ports-what-do-they-do/1451256644913249/
Love the build, your attention to detail and it's killing me you're having engine issues after all you have been through with the entire build. I do truly hope it is something simple so you can enjoy the fruits of your labor.
I got nothing on the engine front, but live a scant 20 miles off your chosen path in Oak Ridge Tn. I'd love to host a BBQ or something.
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