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P/E #426
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Discussion Starter #1 (Edited)
622ci Chevy with dart pro1's. 14-1 comp, I forget the cam specs but its high lift. Motor has seen 150+ passes, most with 200+ shot of nos, and rpms up to 8600. Motor also has gotten fairly hot after a few runs(250+ degrees). Motor was in a T/E jet, now a P/E hydro.

We were finding some shaving in the filter and wanted to make sure nothing was coming apart. At first glance all the bearing looked decent. We were just going to put new crank & rod bearings and have the lifters rebuilt. Anything that we could be missing that should be attended to?

A couple of things that we saw
-A few scuffs on bearings.
-A few lash caps were beat up.
-Black residue in oil pan.


Pictures are on my camera phone so bare with me. I can get all the specs from my father tomorrow.





 

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Boat Nut
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Is that evidence of main caps walking? center of the cap looks to have been moving around??

Cam gear looking alright? check cam bearings, and block face at the cam gear/belt.

Black oil could be excessive fuel....
 

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P/E #426
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372 Posts
Discussion Starter #3 (Edited)
Is that evidence of main caps walking? center of the cap looks to have been moving around??

Cam gear looking alright? check cam bearings, and block face at the cam gear/belt.

Black oil could be excessive fuel....
All the mains were removed and looked over. None show anymore wear then the one pictured. I don't understand where you maybe seeing this.

The cam belt is going to be changed, I forgot to mention that.

Our engine builder said that the black oil was excessive fuel, over the phone.

We have not looked at cam bearing yet. My father seems to think that if the mains look decent then the cam bearing should as well. I'd error on the side of caution and look into it. Then again, I'm not the one paying for everything....

The springs all show uniform spring pressure and it has great/equal compression on all 8.
 

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Look at the bottom of the pistons skirts. The shavings could be a simply as piston shavings. With stroke that long, its not all the unusal. It little looks like ton in you oil.
The cap is walking a little. See the roughness on the machined area around the inner bolt hole on the cap and on the block. Again, hard to control that in a BBC even with splayed steel caps with a stroke that long. You think that the LS, the Ford MOD, New Century and all Top fuel blocks have cross bolts because they are pretty? When you put the steam to an engine, things move. Period! I take it with that compression it gets spun up pretty good even even with that stroke.

The black does look like fuel in the pics. Which could add a little to the piston scuff.

Over all, I'd say it looks pretty normal.

The lash cap thing would have me more concerned more than anything elese.



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steelcomp was here
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How much power is this making? For that rpm and I'm assuming well over 1000 on the juice, I'd say it looks pdg. One thing I'd do would be to lose the stock Dart hardware and get some ARP studs in the center mains. That'll stop what little cap walk you have. You'll need to re-check the main bore and possibly have it honed a stroke or three.
The black in the oil can also be moly that has settled. Are you using Joe Gibbs oil by any chance?
What kind of "shavings" are you seeing? I think if the bottoms of the cylinders were sahrp enough to "shave" the pistons, there wouldn't be anything left of them before long, but I guess stranger things have happened. My thought was something on the heads and/or valve train might be chafing. Sounds like you may have some valve train issues.
Dry sump sure makes a difference.
 

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I agree the black could be excessive moly during the built. Without know the number of hours on the thing or the number of times the oil has been changed, it is possible it is moly.
I agree I doubt that the bottoms of the cylinders are that sharp. But there does appear to be a little wear on the center of the piston skirts. Nothing bad, but that material went somewhere. No telling how littlew material the OP is talking about. With a strike like that, and the limited space to put a decent length rod in it, you end up with a pretty short, rocky piston. It the nature of the beast.
It would be intersting to know if any of the material came from under the springs for some reason.

X2 on the center studs. The cap walk isn't severe, and the studs would help.



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P/E #426
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372 Posts
Discussion Starter #8
I'll pass this along to my father who knows more about the internals then I do. I just wanted to get some more opinions then from his builder.

-We have in the past broken 1 lash cap.

-Everything in the motor has been cyrogenetic'd.
 

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P/E #426
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372 Posts
Discussion Starter #9
How much power is this making? For that rpm and I'm assuming well over 1000 on the juice, I'd say it looks pdg. One thing I'd do would be to lose the stock Dart hardware and get some ARP studs in the center mains. That'll stop what little cap walk you have. You'll need to re-check the main bore and possibly have it honed a stroke or three.
The black in the oil can also be moly that has settled. Are you using Joe Gibbs oil by any chance?
What kind of "shavings" are you seeing? I think if the bottoms of the cylinders were sahrp enough to "shave" the pistons, there wouldn't be anything left of them before long, but I guess stranger things have happened. My thought was something on the heads and/or valve train might be chafing. Sounds like you may have some valve train issues.
Dry sump sure makes a difference.
990 [email protected] 6600/6800, I forget because it was awhile ago. It was cam'd for a jet boat originally and now runs a higher rpm in a hydro. Dry sump would be nice, but at this point he doesn't want to put more $ into it.
 

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Looks better than mine!

I had an Ohio Crank in my 620 that broke last July. It will be going back together in a month or so with a new Sonny Bryant billet. Real similar power numbers and I spray more than 200 also. I just got the ARP main studs in that will assist in beefing up my bottom end. Suggest you follow Bob's advice and do same! I will be looking into coating the crown and skirts of my pistons as well.

Good luck!

John
 

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steelcomp was here
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990 [email protected] 6600/6800, I forget because it was awhile ago. It was cam'd for a jet boat originally and now runs a higher rpm in a hydro. Dry sump would be nice, but at this point he doesn't want to put more $ into it.
Thought maybe it was dry sump. Are you running an external oil pump? I see what looks like a cap on the rear main where the oil pump goes.
 

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Boat Nut
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What kind of cam? if it's a roller, it sure look funny for what you can see of it.
 

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Run the thing. Throw in some bearings and go. I'd leak it down with that many passes on it personally.
Bearings look good. Those "scratches" are nothing. Damn near standard in any fresh engine build. Could be spring material, etc. RUN IT
Wags
Better yet... bring it to KY Lanke and run it.
 

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Run the thing. Throw in some bearings and go. I'd leak it down with that many passes on it personally.
Bearings look good. Those "scratches" are nothing. Damn near standard in any fresh engine build. Could be spring material, etc. RUN IT
Wags
Better yet... bring it to KY Lanke and run it.
Yup, kinda my thoughts FWIW...


990 [email protected] 6600/6800, I forget because it was awhile ago. It was cam'd for a jet boat originally and now runs a higher rpm in a hydro. Dry sump would be nice, but at this point he doesn't want to put more $ into it.
You have almost 1k HP NA and hitting it with 200HP of spray to run 8.0's in a hydro? Defintely not a hydro expert but that sure seems like a lot of HP to run 8s. If you're new to hydros, you might wanna get a guru to look at your prop/gear/hull set up combo to see if you're leaving performance on the table.
 

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P/E #426
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372 Posts
Discussion Starter #17 (Edited)
Yup, kinda my thoughts FWIW...




You have almost 1k HP NA and hitting it with 200HP of spray to run 8.0's in a hydro? Defintely not a hydro expert but that sure seems like a lot of HP to run 8s. If you're new to hydros, you might wanna get a guru to look at your prop/gear/hull set up combo to see if you're leaving performance on the table.
I was mistaken on nos usage. On a single 1/4 pass we use 1lb of nos pulling 1.50 gears, single speed. Runs 8.00 @ 149mph. We race BA deals with gobs more torque similar gears, 2 speed. They all run same #.
 

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I have to agree with everybody here on this one. I think what ever you saw in the oil is typical. More like flecks than shavings. They come from everything from the dizzy gear, pistons skirts, from the small scratches you see in the bearings, etc.

The one thing I think I would look at though is the spring retainers. If they are Ti retainers, and you are hurting lash caps, the valve train might not be all that happy. A surging, spinning spring that hasn't been detailed will act like a chisel on the Ti retainer. Specially if it has a damper. Having a spring retainer break because its been worn away can be ugly, and its easy to inspect. The retainers can tell you alot about whether the valvetrain is happy or not.



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I was mistaken on nos usage. On a single 1/4 pass we use 1lb of nos pulling 1.48 gears, single speed. Runs 8.00 @ 149mph. We race BA deals with gobs more torque similar gears, 2 speed. They all run same #.
Very cool. 1 LB of NOS for a full pass is like a 125 HP shot or so. Like I said, I don't know a lot about hydros just seemed like a lot of HP from what all the hydro guys around here say it takes to run 8's. Good luck!!!
 
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