Head bolts 454 MPI
 

Which head bolt kit for 1999 454 Mag MPI ?
Merc showing $130 per side with kit 8M0102366

I just used ARP for my Gen VI 502 MPIs.
ARP-135-3601

I agree and That's over $20 cheaper than the GMPP headbolts (which I think are ARP also).

Clean oil off the bolt threads (brake clean or etc after using a thread chaser (not tap) and use something like Permatex Thread Sealer.
Also, make sure threads in block are clean too.

I thought Gen VI didn't require sealer because the head bolt holes are all blind ended?
Also, ARP includes instructions for using their particular thread lubricant and the corresponding appropriate torque specs.

Thanks
Also need head gasket for .060 over bore

And the bolts go into water jackets

We are using perfect seal on bolts

Maybe that's 454 vs 502. I'm 100% sure my Gen VI 502 head bolts do not go into water passages.

You are probably right but this is a Gev VI 454 with 502 heads

Findings
502 STD bore 4.446
454 bored .060 over 4.310
The first 502 head gasket set picked up was larger then the bore of the 454.

Felpro gasket 1071041 is for a 454 which is bored and has cut outs for intake valves.
Felpro gasket 17048 is for a 502 being a larger bore doesn't need the same cut outs. Will this work?

Can someone verify kit 135-3601 bolt lengths? Made a mistake and bought a set 135-3607 for 454 and was the wrong one. Had 3 different bolt lengths and 8 of them where 5 inches. Picked up 8 additional which came out as 4.25 long which were real close to factory ones at about 4.125 and short were 2.125. Then noticed the 3607 kit bolts were only 4.0 long, so this is where the problem was noticed because they do not extend thru the full thickness of the block.

Standard Merc bolts for motor are 24 each 4.060 and 8 each 2.060
The STD Merc appears to be for the 502 head

502’s are blind. 454’s go into water. Another bonus of 502’s. :thumbs

All dodge, the arp’s dr feelgood linked are for mark iv- gen vi bbc’s with oe cadt iron heads.
see here.
https://www.summitracing.com/parts/A...1/applications

The lengths may slightly different than ie bolts because arp’s come with thick hardened washers. OE doesn’t.

Also. All dodge, 4.380 headgasket totally fine on a 4.310 bore and stock head.

Thanks much
I didn't get notified of the posting, but this kind of thing happens all the time these days :picard1:

Will look for the 4.380 gasket. Was doing the compression ratio calculator (summitt) and must be entering something wrong because its coming up with 8.1

Bore 4.31
Stroke 4.0
Cyl head vol 118cc
Piston vol -2 (using standard pistons)
Deck .018 (std deck .018 to .020)
Gasket .039


https://cimg8.ibsrv.net/gimg/www.off...3ebddb4e0c.jpg

This motor does not want to be built

Installed heads and tightened bolts down in 4 passes. FelPro said wait 10 minutes and loosen each bolt one at at time and retighten to spec in one pass. Never done this before but ok since FelPro stated.

Well one of the block threads said NO and heard a crack and it wasn't from the torque wrench. Removed the bolt and piece if thread on the bolt. bolt is fine but not the block. So we have a Helicoil ordered and another head gasket.

you can reuse the head gasket,no need to replace it just because it was torqued down.

Yup, should only need to replace if heat cycled.

ok, will advise, but $50
The motor goes in a 37 foot cruiser inboard which has to hire a semi to haul out

What are you torquing them to ?

Canadian Torque.
Tighten it till it breaks, then back off a hair. :)

89 on long and 92 on short

Still not getting notified of postings

Whose bolts ?
I don’t remember torque values this high, but been a few yrs for me on a 454.

ARP and torque is 92 long and 89 short

https://cimg2.ibsrv.net/gimg/www.off...8dd801fdc4.jpg

That looks like Mercruiser Manual, no ?

Torque values and procedures to use are those of the head bolt or stud manufacturer.

Merc yes, APR states torque in passes to 70 then final torque is per OEM

No.
Just the sequence is OEM.
Torque value is from the bolt and lube used.

The statement from ARP is one which puzzles me some. ARP states the bolts are stronger then OEM but they use OEM spec for final torque. Torque should stretch the bolt so it maintains the clamping load. If their stronger then the same torque would not stretch the bolt the same and provide the same clamping load, or at least IMO

Here are the directions for those bolts.
https://tech.arp-bolts.com/instructions/135-3601.pdf

89/92lbs is a lot on a 7/16 bolt/stud.

1/2" are usually 100lbs.

Your right both instructions are the same, we over torqued.
I should have read the paper instead of listening to what my friend said it was saying. So its over torqued.

Will loosen each one at a time and torque to 70

Wonder if it crushes the gasket to much?