so i was driving from mountain home to boise, on I-84 today, going to work. Last night while driving home, i was dicking with maxing out my psi without hitting fuel cut, adn got it to a safe area. Apparently i forgot to put the bc back to low boost mode, because today while driving up to boise for work again, i was passing a beamer and goosed the throttle, (in high boost, mind you)hit a bit of fuel cut, and as soon as i let off, i see the high boost on the gauge had hit 15.6!!! it scared the shit out of me immediately, as i was warned not to go anything over 13 with my current setup, even on a spike. when i was getting ready to turn off of the interstate, i feel something knocking under my feet. i say to myself oh shit, this can NOT be good, so i pull over into the closest parking lot which happens to be a goodyear tire center. my temp gauge is going up a decent bit, on top of the knocking which is even worse, but thats for later. Now i have rod knock and a blown headgasket(i think, as the oil cap smelled so damn nasty from the radiator fluid mixing with the oil). What are my fixes, and how much should it cost without labor???
Rod knock... i guess...
- Thread starter kingofyo1
- Start date
depends on what you want to do to the motor and how much damage is done....what are your power goals? But to give a ruff idea...$1500-$10,000
Tried to narrow it down for you...
Tried to narrow it down for you...
kingofyo1;1183128 said:
What is the mileage of the engine?
New Rod/Main bearings and turning the crank will set you back about $300(I just paid $305 locally here in CA). Figure about $90 for gasket kit from Partsdinosaur.com, and machine work for the head if needed. With it it out and apart you should go ahead and install new rings on the pistons, figure another $60-120+ for oem/oem replacement, and about $200 for an oil pump from driftmotion.com. If you don't have them already a MHG and ARP studs will run about another $250+ depending on where you buy. I just spent about $1020, to rebuild my lower end myself for a rod knock. this price was for oem/oem quality parts, and my pistons and rods were all still good.
actually no junkyard. my buddy ordered a new crank online last night for me, and the damn thing had acl bearings in there, which is why i cant see this happening. has arp studs and a hks mhg as well. it was just the boost spike eff'd me over i guess. gotta go drive the el camino to work now v.v *TEAR*:*(
An HKS MHG is pretty picky about deck surface smoothness. That's for both the head AND block decks.
Ok, question though. Is the mhg reusable? Oh and mileage is 2k since rebuild on the engine. Does the engine have to come out of the car to replace the crank and bearings or not?
I would pull the engine and tear down the whole thing. You already have to pull the head and the lower end apart, so I would pull the engine, it will make all the other work easier. Oh and did you retorque the headgasket after a few warm up and cool down cycles, the studs may have loosened up a bit causing it to be undertorqued. What did you torque them to?
Do not reuse a head gasket. Cometic MHG's are not so picky and considered by many other car guys to be the best, but there not a huge name in the supra community.
Actually you can re-use a MHG...the old factory Viton coating has to be stripped off though, including between the layers. When you re-install, you use copper spray (between layers too) to replace the Viton coating that acts as the seal on a new MHG.
Personally, I would pull the motor. Since the new crank is of unknown history, I'd have it thoroughly checked for balance and make sure it is straight...micro polish the journal at minimum. Size the new bearings (get Clevites or NDCs) to the journal diameters. The problem is going to be with the rods...they actually need to be re-sized too, but you will have to pull the pistons to do so. That means a cylinder hone and new rings too, assuming the cylinders are in good shape. If you go this far, you should have the block decked for the HKS MHG...the RA spec is 30.
The machine work adds up fast
Personally, I would pull the motor. Since the new crank is of unknown history, I'd have it thoroughly checked for balance and make sure it is straight...micro polish the journal at minimum. Size the new bearings (get Clevites or NDCs) to the journal diameters. The problem is going to be with the rods...they actually need to be re-sized too, but you will have to pull the pistons to do so. That means a cylinder hone and new rings too, assuming the cylinders are in good shape. If you go this far, you should have the block decked for the HKS MHG...the RA spec is 30.
The machine work adds up fast
Crypton2006;1183535 said:
Hks is by far the best gasket.....all metal gaskets should be done to hks standards of ra specs....a metal gasket is a metal gasket and the smoother the decks the better....cometics are probably the most popular as they are cheaper and have every damn size you could need and they also will make you one with custom dimensions...
You will definetly want to pull the motor to do all this as it will be much much faster and easier.
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Im going cometic for my build.... stock rods and pistons, figure i dont need a hks and have a little more peace of mind about how well it will seal
To do it correctly (insure a good seal) the block will need to be decked in addition to the head. The only difference with a Cometic is the surface RA spec is a bit higher...50 RA vs 30 RA for a HKS. Installing any MHG (including a Cometic) on a block that has not been decked is a crap shoot.
What's really important is the head hardware is torqued to the correct spec
70-75 ft/lbs for stock head bolts, 75 ft/lbs for ARP bolts, and 80 ft/lbs for ARP studs (both ARP using moly lube). More than that and you are decreasing the hardware safety margin for yield strength due to the different thermal expansion of the aluminum head on a steel block.
What's really important is the head hardware is torqued to the correct spec
70-75 ft/lbs for stock head bolts, 75 ft/lbs for ARP bolts, and 80 ft/lbs for ARP studs (both ARP using moly lube). More than that and you are decreasing the hardware safety margin for yield strength due to the different thermal expansion of the aluminum head on a steel block.
Learn something new every day! What kind of solvent would one use to strip the Viton Coating?jdub;1183546 said:Actually you can re-use a MHG...the old factory Viton coating has to be stripped off though, including between the layers. When you re-install, you use copper spray (between layers too) to replace the Viton coating that acts as the seal on a new MHG.
Unless your talking about a HKS stopper MHG the cometic is around the same price as the standard bead gasket. Sometimes the machining required (RA 30) is not feasible. I live in a small town and there is no one with in 100 miles that can get it that smooth. The "BEST" MHG is going to be the one that fits your particular needs.
One particular build I did I had pulled the motor and send the head in for inspection. The cylinder head was out .011 and befor i pulled the motor it had no signs of BHG. I was running a cometic and that kind of impressed me.
Paint thinner or acetone works well.
Lapping plates are available at McMaster-Carr...that and diamond paste makes short work of getting the RA to spec.
A flat head/block deck is just as or more important to ensure a good MHG seal.
Lapping plates are available at McMaster-Carr...that and diamond paste makes short work of getting the RA to spec.
A flat head/block deck is just as or more important to ensure a good MHG seal.
do you think a smooth 5x8 plate and some of the fine paste would be good?jdub;1185027 said:Paint thinner or acetone works well.
Lapping plates are available at McMaster-Carr...that and diamond paste makes short work of getting the RA to spec.
A flat head/block deck is just as or more important to ensure a good MHG seal.
That will set you back about 120 + shipping
A 5x8 will work...you need enough surface to use a circular motion as you move down the length of the deck.
It depends on the machined finish...if the machine shop used a CBN cutter, 10/Green will be all you need. If it's a std finish (you can feel slight ridges with a finger nail), I'd start with a 30/Red and finish with a 10/Green.
Make sure you block the coolant/oil passages and the bolt holes in the block...foam plugs work well with a light layer of grease on top. Don't forget to chase the block bolt holes too
It depends on the machined finish...if the machine shop used a CBN cutter, 10/Green will be all you need. If it's a std finish (you can feel slight ridges with a finger nail), I'd start with a 30/Red and finish with a 10/Green.
Make sure you block the coolant/oil passages and the bolt holes in the block...foam plugs work well with a light layer of grease on top. Don't forget to chase the block bolt holes too