What Head Gasket
 

Hey Guys

Geoff in Sydney here, our SB Chev Dragster has lifted a head gasket twice now in about 50 passes and it's become a pain in the arse.

400 + 030, flat tops, small roller, 23 Deg Iron Darts, 850 DP runs on EX02 Sunoco, 36 deg total timing, sees 7600 in the lights, weighs 1505 with driver, runs 8.11 @ 159 mph.

We got it hot (runs coolant) about 50 runs ago and it pushed up the head gasket where the steam holes are allowing cylinder pressure into the water passages and spewed all the water out, now we have had it happen again.

We run Felpro #1004 gaskets and because I haven't played with a SB since the 90's I can't remember if we can put a set of #1003's on it which DO NOT have the holes for the 400 steam holes, the reasoning is the Heads don't have any holes so why should I run #1004's?

If anyone has any helpful info that would be great, as always this place and the people on it ROCK.

Thanks again guys.

Geoff in Sydney Australia

Re: What Head Gasket
 

The 1003's are to small on the bores for a 400. The 1004's should work for you. You can step up to a Cometic or FP MLS with a bore size to fit your engine.

Re: What Head Gasket
 

be aware the surface finish (RA) for a MLS gasket is much finer than for the composition type gasket...

Re: What Head Gasket
 

With iron heads and block we always ran steel shim head gaskets with close to 14:1 comp. at 9,000 rpm

Re: What Head Gasket
 

Use a 1010 it pulls the fire ring back from the edge of the cylinder more and heat doesn't get to them as quick. Make sure that the chamfer on top of the cylinder is not too wide and getting into the edge of the fire ring. Lay the gasket on the head and check fit of the chamber. Extra porting might have chamber overhanging the fire ring. It can't seal when it is out in the combustion chamber heat.
Re torqur after the first days usage. I mean Torque it properly, don't just set the clicker and drop it on and pull till it clicks. Back each bolt up 1/4 to 1/2 a turn and in one pulling motion keep the bolt moving until it clicks. Torque should be reached while the bolt is moving. You are reading torque that way and not static friction loads of under the bolt head and the threads. Last...back the timing up from the 36 or 38 you probably have it at and keep it around 32-34 max.
Good luck

Re: What Head Gasket
 

As always thanks heaps for the info, particularly Adger cause when I pulled it apart the energy needed to loosen the bolts was all over the place...in other words some bolts were tight and others, well you get my drift.

We also put new ARP Head and intake bolts into it, for the $120 it was cheap insurance, will report the results.

And to those following (laughing lol) our exploits the BB car with the throttle stop has yet to work properly since the last exploit, we figure it's fixed now and just gotta wait till we can do a lap or two.

Again thanks heaps for ALL your help.

Geoff in Sydney AUSTRALIA

Re: What Head Gasket
 

Geoff…I've drilled and tapped the steam holes to 5/16 NF and Locktite Gr-8 studs (plugs) into the block and deck it flat. If the heads don't have the holes you don't need them in the block. Use a Cometic gasket with the iron head you should never have the problem again. MB.