SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: Joecochrane on June 22, 2014, 04:38:48 PM
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About a month ago I lost the bottom end in my 455 still runs but has a bad knock. So yesterda I bought a almost complete 455 from steve86ta off of here. Motor is torn apart but cleaned ready for assemblie just needs rings and rod bearings. So my build plans are
Std crank
Stock rods
New bearings
Arp rod bolts and main studs
30 over forged hi comp pistons
Clay smith .520 lift cam (can't rember the rest of the specs)
New lifters
Eitther restricted push rods or stuff roll pins into my stock one cause I'm cheap
Oil restrictors in the block (read a few differnt ways of doing this so somne needs to lern me)
12qt pan
I have ka heads with aftermarket springs and retainers or I have c heads off my old motor
Offy tunnel ram with two 600s
Malory unilite
And im probaly gonna build a set of zoomies just because I like to be the loud obnoxious d bag in my group.
Gonna probaly do external oil drains so if any one has a write up on where to drill and how to do it please share.
All said and done I will be into the entire engine for under a grand and I hope it will last the rest of the season. Plan on swaping in a carb'd turbo ls motor next just don't want my boat down while I gather parts.
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Dont do zoomies, not on an olds. Olds motors want a little back pressure. and theres the whole thing with the center cylinders .
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Dang but I really want em. Wonder f I could weld up some baffles inside of em to create a lil back presure
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Dont do zoomies, not on an olds. Olds motors want a little back pressure. and theres the whole thing with the center cylinders .
X2 on the Zoomies. Not a good idea, you'll loose hp unless it's a blown app.
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I know there pointless and that I will lose the scavenging affect of headers but will I really lose a noticeable amount of hp on a motor this mild? Every "rat rod" guy runs them on stock junk yard pos motors and don't seem to have a problem. But forget the zoomies if I do build set I'll keep my bassetts so I can switch back. Tunnel ram a dual 600s are pointless on my motor to butthey sure look neat.
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No need for external oil return....
Open the returns up in the head.
Again if you want the motor to last, don't be cheap
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I'm not sure where I'm being cheap but I have absolutely zero intentions of keeping this boat olds powered I just fell into 90 percent of a fresh olds motor for damn near free. If it runs all season I'll be happy I don't need it to last more than a few trips and inplan on going easy on it in hopes its still running when I'm dome with it.
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No need for external oil return....
Open the returns up in the head.
Again if you want the motor to last, don't be cheap
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Best piece of advice so far!
Get threaded main restrictors. Since I now know the secret, ( thanks Drew) some plain 1/8 NPT internal plugs with about a 60 thou hole thru them will be good.
Also, you want to open the #5 main cap where the oil pump sits. Also, don't forget to shim the oil bypass about 3/16.
Also, you must notch the big end of the conrods and make sure you have correct rod clearance.
Get some good rockers that have some sort of adjustability to them. Restricted pushrods are not mandatory since you will be restricting the mains.
The pistons you have are not high compression.
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How big do I open the returns in the head
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I'm not sure where I'm being cheap but I have absolutely zero intentions of keeping this boat olds powered I just fell into 90 percent of a fresh olds motor for damn near free. If it runs all season I'll be happy I don't need it to last more than a few trips and inplan on going easy on it in hopes its still running when I'm dome with it.
With that mind set, why even build it in the first place?
And what's the point of asking for knowledgable advice on how to build one... Just throw it together, keep one eye closed! And putt putt it around the no wake zone
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When I said high compression I meant "higher" I think they are the 9.5ish ones but I'm just going by pictures of pistons I fond online.
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When I said high compression I meant "higher" I think they are the 9.5ish ones but I'm just going by pictures of pistons I fond online.
They are LOW compression, the lowest you can buy
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Because I'm gathering parts to put ls motor in her but I don't wanna be boatless while I wait. Im putting quality parts in it planed on doing arp bolts through out and what ever brand gaskets you guys recomend. Also plan on doing any oil mods I can do my self in my garage. Machine work is done already and I already have the rotating assembly. So I don't see how I'm being cheap still need to buy rod bearings so if there is a perfered brand let me know.
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So 8ish to one? How can you tell just expeirence? Or is there a trick?
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Spend ur money elsewhere... Stock lower end bolts are fine for your application.
The mods that you need to do on the lower end require grinding/porting... With that said, once done, the block will need to be re-hot tanked and thoroughly cleaned.
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So 8ish to one? How can you tell just expeirence? Or is there a trick?
Both !
I can teach you the secret trick, look up the part number stamped on the piston!
Any factory replacement piston with a dish deeper than .125 is low compression.
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Tried to google the part numberyesterda dindnt come up with anything
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Dish is about .140 though
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So 8ish to one? How can you tell just expeirence? Or is there a trick?
Read a little, that helps. Olds motors require someone that knows whats going on , when assembling them , that also includes what parts to use as in your choice of heads. Id use the Ka heads (but thats just me)
My first olds motor spun all the crank and rod bearings!!! I DID not build it. but it took less than 10 minutes to do it.
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The pistons you have are old school TRWs
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2287p is the part number people said trw and some said speed pro. But only info on the dish I found said .250 dish and mine are .140 so between that and looking at pics I assumed theywere high comp.
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2287p is the part number people said trw and some said speed pro. But only info on the dish I found said .250 dish and mine are .140 so between that and looking at pics I assumed theywere high comp.
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when i looked into them when i was looking at putting it together. I think that with the KA heads it is right about 8.5-9:1 so it is low compression by most anyone's standards.
They are speedpro pistons.