Guest Fast Four Special Posted July 5, 2012 Posted July 5, 2012 Can anyone tell me the cylinder head torque specs for a 1928 DB Fast Four?Thanks in advance!
Pete K. Posted July 6, 2012 Posted July 6, 2012 I've noticed your question has gone un-answered for a time. I hope it's not holding up your work on the engine. I do not own a "Fast Four", but if you torque the head nuts in the proper sequence to 55-60 ft. lbs, I would think you'd be right in the proper torque. I get this information from the Ford Model A spec's which uses a very similar, cast iron four cylinder engine, using a standard copper head gasket.
MikeC5 Posted July 7, 2012 Posted July 7, 2012 I'm not sure about '28 but for the earlier fours there were no torque specs. I guess it was assumed any good mechanic had the 'feel'...
Guest Fast Four Special Posted July 7, 2012 Posted July 7, 2012 I've noticed your question has gone un-answered for a time. I hope it's not holding up your work on the engine. I do not own a "Fast Four", but if you torque the head nuts in the proper sequence to 55-60 ft. lbs, I would think you'd be right in the proper torque. I get this information from the Ford Model A spec's which uses a very similar, cast iron four cylinder engine, using a standard copper head gasket.As you may have seen from my other post, I use a Fast Four in a vintage race application. We have twice had block failure in the same location (adjacent to the end corner studs), and I'm trying to analyze the reason before the head goes on for Bonneville this season to hopefully avoid another failure.I was curious if the original torque specs were abnormally low, and that the 65 ft/lbs we use for our aluminum head were potentially too high for the architecture of the block and contributing to the problem, but it sounds as if we are close to stock specs.Thanks for the response!
R.White Posted July 7, 2012 Posted July 7, 2012 Intrigued by this question, I have contacted a 'special' racing guru freind of mine who wanted to know how much boost you have from the blower; what is the compression ratio? - it should usually be lower than the normally aspirated engine, so torque would not need to be too high. There is apparently a lot of information on the net if you know where to look. There are formulas for calculating the optimum torque; it is to do with the size of the studs and their tensile strength and the grade of head/ block material. It all sounds pretty complicated to me but one suggestion is that Ford v8 guys would also be able to help. I guess that would depend on what they felt about you winning with a Dodge...... Ray
Guest Fast Four Special Posted July 7, 2012 Posted July 7, 2012 Naturally aspirated we ran 11.2:1 compression and had no issues. Supercharged we ran 9:1 staic compression with 4# of boost which equates to a static boost compression of 10.6:1. There has been no indication of detonation. We are running less static compression with more boost this year.We are hoping to have the problem licked this year with additional studs that run all the way from the head through the block to the 3" billet bedplate that incorporates the main bearings. We will no longer be depending solely on the strength of the deck to retain the head.Considering they made MILLIONS of Ford blocks and 50,000 Fast Fours (from what I calculate from cars and Graham trucks), we are working with a very limited resource.We are a bit paranoid about Ford conspiracy theories
R.White Posted July 7, 2012 Posted July 7, 2012 I like the proposed solution. You should have a much stronger set up and I hope it works for you. It reminds me of a single cylinder motorcycle (BMW) engine I had problems with. In that, the barrel fastening studs would work loose in the aluminum crankcase. The least of my problems was a bad oil leak and the worst case scenario was the barrel fracturing. By replacing the four studs with bolts passing right through the crankcase, the barrel could be tightened down securely to the crankcase with no chance of working loose. As to the limited supply of old blocks. Here, we have an enthusiastic Austin 7 racing fraternity. Unlike the Dodge Brothers, Herbert Austin went racing - so there is historical precedent. When the supply dried up, one of our more enterprising club members had some more iron blocks cast. He machined them to suit the formula rules and so far has sold about 80 of them. Other castings have been equally successful - in fact I have just purchased 4 new cast iron brake drums for my Austin Swallow road car and (although I had to finish them off on my lathe) they are a big improvement on the original pressed steel ones which had seen better days.If the Ford guys realise (what we could have told them all along) that Dodge Brothers iron is better, they will all be wanting some!Good luck,Ray.
Guest Fast Four Special Posted July 8, 2012 Posted July 8, 2012 Ray,I'll make you a deal. You find me 80 buyers for NEW Fast Four blocks and I'll pay to have them cast! Pete
R.White Posted July 8, 2012 Posted July 8, 2012 Ray,I'll make you a deal. You find me 80 buyers for NEW Fast Four blocks and I'll pay to have them cast! PeteThe impossible I can handle - miracles may take a while!Ray.
Guest Tony Montana Posted July 8, 2012 Posted July 8, 2012 The Dodge Brothers Mechanics' Instruction Manual says: "Repeat this procedure (tightening the head nuts from the center outward) until the nuts are very tight". Sounds like 50-60 foot pounds to me!As an aside, no torque specs are mentioned anywhere in that book, not even for the much more critical rod and main fasteners.
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