1966 Toronado 425 V8 engine overhaul need help

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Otto Skorzeny
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby Otto Skorzeny » Thu Mar 25, 2021 6:06 am

I also use 15w-40 in my Toro. Actually Shell Rotella T4 15w-40. It's made for diesel engines and has a higher zinc content than other oils. Just don't put in in a vehicle with a catalytic converter.

ochaffard
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby ochaffard » Fri Mar 26, 2021 2:14 pm

Dear Bruce, Roland and Otto , first thanks for your insights ... I think I may face a serious issue ... let me share details and sequence with you to have your point view.

My engine just got out from restoration , with forged Mondello pistons , new camshaft, new lifters , new rockers , new valves , etc etc .. with a HV and HP oil pump from Mondello too .

Oil is Lucas 30 special breaking oil. Engine put on oil pressure before first start.

First quick start ok, for a few minutes, no noise at all.

I checked advance , etc ... and ready for breaking-in ... 2000 rpm for 20 mn.

When engine went back to idle ... very noisy engine , obviously coming from the valve train .

We checked oil pressure :

Engine cold, at idle (750/800 rpm) : 40/45 psi .... at 2000 rpm : 60 psi . Valve train still very noisy at idle, less when rpm increase

Engine hot and stabilized, engine temperature perfect , idle 7/10 psi ... engine still noisy ... at 2000 rpm : 20-25 psi ... valve train less noisy

So .. any comment/advice based on your experience with those 425 engines ?.

Thanks in advance for your time !

Olivier
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Otto Skorzeny
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby Otto Skorzeny » Fri Mar 26, 2021 6:55 pm

Can you tell if it's a lifter noise? Assuming the people who built the engine know what they're doing and everything is correct, my first thought is that it's a hydraulic valve lifter that's stuck. There's probably a piece of crap or something stuck in the lifter orifice.

Does it sound like it's isolated to certain cylinder or is it all over?

Of course you never can tell with "new " parts. Do you know the origin of the parts used on your car? A lot of rebuild kits sold by companies like Kanter are cheap Chinese crap.

After it warms up you say i'ts still noisy but not as noisy as when it's cold? That's often consistent with a lifter noise.

Post a video on you tube so we can hear it.

Better a top end noise than a bottom end one, though.

ochaffard
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby ochaffard » Fri Mar 26, 2021 8:17 pm

Hi Otto, it is our first conclusion too ... despite we are a bit confused by the low oil pressure when hot ... we are going to use the old set of lifters , as a test , as the engine enjoyed a silent valve train before rebuilt. Will keep you posted .

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roland
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby roland » Sat Mar 27, 2021 7:33 am

Are your new lifters really for a Toronado 425? Its a special design with 0.921" diameter and was only used with 1966-67 400 and Toronado 425 engines! I tried very often and hopeless to get a new set. Not at Rockauto or other performance auto shops. Mostly they try to sell 0.8425" lifters - they don´t work in our engines!
Good but used lifters was the only possible choice. I dismount and cleaned them very accurate before I reuse em...
Roland TOA#860

Willysnut1959
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby Willysnut1959 » Sat Mar 27, 2021 9:34 am

Olivier,
Did you install Mondello's oil restrictors in the block when you rebuilt it? These will reduce the oil pressure at the sending unit. After installing these on my 442, the oil light comes on when my engine is hot and at idle.

Secondly, was the plug reinstalled on the oil gallery at the rear of the block?
Marty

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Otto Skorzeny
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby Otto Skorzeny » Sat Mar 27, 2021 9:43 am

Roland, that's excellent information. I was never aware of that. Fortunately my engine isn't in need of a rebuild yet.

I've found with other cars, though that rebuilding and/or reusing old parts is frequently superior to modern "new" parts. Rocker arms, etc are all cheaply made in China these days. Best to have original parts machined, straightened, etc.

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1966 Toronado 425 V8 engine overhaul need help

Postby bcroe » Sat Mar 27, 2021 11:21 am

roland wrote:Are your new lifters really for a Toronado 425? Its a special design with 0.921" diameter and was only used with 1966-67 400 and Toronado 425 engines! I tried very often and hopeless to get a new set. Not at Rockauto or other performance auto shops. Mostly they try to sell 0.8425" lifters - they don´t work in our engines!
Good but used lifters was the only possible choice. I dismount and cleaned them very accurate before I reuse em...


The surface of the lifter riding the cam, can certainly be worn out. This must
be a big problem for all the 66-67 cars with the big block. It has a forged
crank, but the flex plate is another problem, esp on a Toro. Almost enough to
make you go to a 455 with all these problems cleaned up, I use 403s because
they will just run and run on crap 87 unleaded. Bruce Roe

ochaffard
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby ochaffard » Sat Mar 27, 2021 2:02 pm

Roland, it is exactly what we have decided to do ... clean carefully the old set of lifters and put them in the engine. This will be done on coming Tuesday. We checked them and the hardened bottom of all of them and it seems they are in quite good shape, showing only minimal wear .. we will see

Marty, no , no restrictors installed . I do not know the answer to your second question ... will ask my rebuilder .. any idea how to check easily if that end plug is in place or not ?

I will keep you posted on progress ...

Thanks to all of you for your time and comments/advices,

Olivier
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ochaffard
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Re: 1966 Toronado 425 V8 engine overhaul need help

Postby ochaffard » Tue Mar 30, 2021 8:25 am

Hello to the 425 Engine Team ! ... we just spent a few hours on the engine ... and found the culprit ! .... during rebuilding process , we installed hardened exhaust valve seats for lead free gasoline ... and for a reason my reason , and my old rebuilder’s one too , ignore ... they forgot to adjust those valves length accordingly... consequently the exhaust valves length above head upper surface are out of spec and so the related hydraulic lifters were just not able to operate correctly , being way out of their « comfort zone » ... so we have just taken out both heads and will rework that stupid error very quickly ...
I will share with you the results the coming week !

By the way we used the opportunity to double-check camshaft surfaces, each hydraulic lifters , pushrods , rocker arms ... and all are in perfect condition.

Let’s see ...

Olivier
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