i had planned on using a titan motorsports mhg. but whats better to use head bolts or head studs? i know they are relativley the same price but whats the main difference? is there anything else i should change while im in there?
using factory hg?
- Thread starter Godspeed
- Start date
There is an awful lot of info about HG's on this site...I've posted on it dozens of times...learn to search.
I will tell you this, if you are planning to use a MHG both the block and head need to be machined to the RA (smoothness) spec for the MHG used...failure to meet this spec is asking for a repeat BHG. The head/block must be perfectly flat. The motor will have to be pulled to machine the block.
The Titan is a Cometic...that spec is 50 RA. It has rivets that "can" interfere with the head seating on the block...they need to be removed. Thickness of the MHG is determined by how much material is removed from the head/block decks. Stock thickness is 1.37mm.
ARP studs are a better choice over the bolts...better/more even clamping force. They MUST be torqued to the ARP spec on the sheet.
If you pull the head, check the valve seats, guides and replace the seals...might need a complete valve job. Having the exhaust studs helicoiled is a good idea...these tend to strip. You will also need numerous gaskets, might as well get a head kit...I prefer the Toyota OEM kit.
If ANY coolant got in the oil pan, you MUST change the oil...I'd do it at least twice in a short period. If it was run with coolant in the pan at all, it is very likely the bearings were affected...this is a VERY common reason for follow on rod knock after a BHG.
I will tell you this, if you are planning to use a MHG both the block and head need to be machined to the RA (smoothness) spec for the MHG used...failure to meet this spec is asking for a repeat BHG. The head/block must be perfectly flat. The motor will have to be pulled to machine the block.
The Titan is a Cometic...that spec is 50 RA. It has rivets that "can" interfere with the head seating on the block...they need to be removed. Thickness of the MHG is determined by how much material is removed from the head/block decks. Stock thickness is 1.37mm.
ARP studs are a better choice over the bolts...better/more even clamping force. They MUST be torqued to the ARP spec on the sheet.
If you pull the head, check the valve seats, guides and replace the seals...might need a complete valve job. Having the exhaust studs helicoiled is a good idea...these tend to strip. You will also need numerous gaskets, might as well get a head kit...I prefer the Toyota OEM kit.
If ANY coolant got in the oil pan, you MUST change the oil...I'd do it at least twice in a short period. If it was run with coolant in the pan at all, it is very likely the bearings were affected...this is a VERY common reason for follow on rod knock after a BHG.
i tried searching but kept getting a bunch of stuff not really related to what i was asking! i did however find your post about the studs bolts etc last night after looking for a while. i thank you for your help on this matter and i will take you advice to heart because i only want to have to do this once!!!
i just have one more thing to ask.
which mhg would you suggest using?i dont wanna use a tm ones if it can possibly interfer with the head seating correctly?
i just have one more thing to ask.
which mhg would you suggest using?i dont wanna use a tm ones if it can possibly interfer with the head seating correctly?
jdub said:^^^ The stock HG is good to fuel cut...even on a Lex AFM would be ok, but that will be pushing the upper limit. This assumes an installation with attention to detail and ARP hardware. Above that, a stock HG's life is limited
I don't agree with that. If you are using a true OEM headgasket then yes. As in the headgasket that was installed in 1989. A new gasket on decked surfaces is a pretty good piece.
Composite has its upside besides price. That give in the gasket is supposed to take up the different expansion of the head and block's dissimilar properties.
But you are correct in that 350 hp is not what they had in mind. I wouldn't debate that.
Godspeed said:
There is nothing wrong with the Titan MHG...in fact, it's one of the better ones due to the higher RA spec (HKS is 25-30). All you have to do is lay the MHG on the block and see if any of the rivets are on the deck surface or touching it...just remove the rivet with a set of shears and you are good to go.
A couple of other things:
- If the block is machined, the front inner timing cover has to be machined with it or the MHG will not seat.
- RTV has to be applied in two locations on top of the front inner timing cover prior to laying the MHG down. The exact locations are in the TRSM. Forget this and you will have an oil leak.
- DO NOT use any type of spray sealer on a NEW MHG.
Nick - Yeah, I was talking about a new Toyota OEM HG
so if the car is still in running cond. as in the hg is not blown out yet do you have to get the block resurfaced to use a mhg?
is ther another mhg thats i can use that i wouldnt have to do any adjustments to make it seat right?
like not having to remove a rivet? hks? hpf? any others? also will they resurface the block with the pistons inside still?
is ther another mhg thats i can use that i wouldnt have to do any adjustments to make it seat right?
like not having to remove a rivet? hks? hpf? any others? also will they resurface the block with the pistons inside still?
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