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safe · Joined: 18 Mar 2017 Posts: 586 Location: Sweden

I really don't see a need for arp head studs in an NA application.

Juho · Joined: 03 Oct 2018 Posts: 377 Location: Finland

Juho · Joined: 03 Oct 2018 Posts: 377 Location: Finland

MikeJinCO · Posted: Wed Oct 02, 2019 10:34 pm Post subject:

The ARP head studs are for a Ford Sierra Cosworth #251-4701 and are $135 from Summit racing or maybe 110E. The crankscraper guy is an absolute ripoff, I ordered and paid for two, got one. When I last checked he was not very healthy. Maybe a change by now.

When porting manifolds make your own gasket patterns, the gaskets are too big. enlarging to the gasket will make the air slow down then re accelerate. If using the stock CI exhaust manifold, grind it out to smooth it and match the head and header. It is a very poor and rough casting and very hard cast iron. Between 77 and 78 they added another cooling fin to the casting as my '77 did crack.

My 10+ CR race motor with mild cam, MSDS header and webers is at an entire different performance level, even with just guessing the proper carb jetting and timing.
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Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

Juho · Joined: 03 Oct 2018 Posts: 377 Location: Finland

MikeJinCO · Posted: Thu Oct 03, 2019 3:03 am Post subject:

I have no idea as to power, the car is probably 150-200kg lighter also. It is so different it is unbelievable, when accelerating in 3rd you get shoved back in the seat a bit,not the sedate acceleration as in a stock one. Since I think my street car has a blown head gasket it will get a Cometic head gasket and ARP studs when it goes back together, it is just better made parts. The old bolts are 40 years old and the new ones may be Chinese junk, having worked in the piston ring industry, aftermarket even brand name parts(particularly obsolete ones) basically have no quality control. It may cost more, but you only have to do it once. Also getting a thinner Cometic head gasket(.040 vs .065) increases the CR. I think it will be necessary to pull the hood using the ARP studs.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

daniel · Joined: 18 Jun 2009 Posts: 670 Location: Sydney, Australia

My motor has 125rwhp (probably 150-160 at flywheel) with the following mods:
- Mild Cam (30/70 from paeco)
- Standard turbo head, valves and springs
- Cometic head gasket to give 11:1 compression
- custom forged flat top pistons
- polished rods (to remove weight)
- lightened flywheel
- bottom end balanced and blue printed
- basic port and polish job of head and inlet
- home made mandrel bend exhaust (not equal length due to RHD car and steering column interference)

10 years racing with only oil changes.
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Over the top of skyline, total brake failure.... hit the wall at over 200 kp/h at the dipper, so anyone who has to brake for the esses is a pussy.
1977.5 Race Car, CAMS Group S Spec
1989 944 Cabriolet