MG Sports Cars

Just been reading about K Line Bronze valve guide liners and wonder if anyone has experience with this product.

I have a pair of alloy Buick 300 heads in very good condition, the existing valve guides are obviously a little worn on 43 year old heads and was intending to have them replaced with bulleted bronze guides but having seen this product thought they might be a better solution and involve less stress on the heads.

Link.

.[guideliner.net]

Kevin.

Kevin,

One of our V8 brothers does. He did a nice write up about it a few years ago:

[www.britishv8.org]

Dale Spooner is the guy who is doing the work on the engine for the Roadmaster. I sent him my 300 heads to freshen up and trust him to do just what is needed. As he mentioned, the 300 may have concentric guides and probably do. If so a guide replacement properly done shouldn't stress the head unduly. The thing I would be most concerned with on the liners is the chance of them moving in the guide.

Jim

Thanks again Carl, I read and saved Dale Spooners article on the K-Liners.

Jim, I'd be interested to hear what Dale recommends on your 300 Heads. Are you changing the exhaust valve seats to unleaded hardened spec?

I bought a 77mm crank just before Chrismas and then got a 3.9 bottom end/half engine off e-bay for £56.00/$115.00 so have got the basis for my 4.35 engine, just need to get the Chevy 305 flat top pistons and the heavy duty 5.85" rods to get to make all fit together dimensionally.

Do you think a 4,35 engine is going to be big enough for the Buick 300 heads, it's going to be mainly a road engine and I have a slight concern about low RPM behavior, although it will have a fairly mild cam, I was thinking it might produce 260+ BHP with a stage one job on the heads and an increase in exhaust valve size to 1.4" I intend to use a Hot wire injection system with the manifold matched to the 300 inlet ports.

Kevin,

Kevin, I think as long as you pay attention to the piston height and chamber volume so that you have enough compression that you'll be just fine. There could be some shrouding of the valves due to the smaller bore but I haven't looked to see how much smaller it is. Are you aware of any complaints of valve recession? I've not heard that replacement of exhaust valve seats is necessary.

Dale won't be looking at my heads for maybe as much as a month since he has to pick them up from Carl's place but after talking to him I think I'll probably stick with the stock valve sizes because seat and valve replacement is pretty expensive and good port velocity should contribute to economy which is an important part of this build. The motor you are building isn't much smaller than a 300 so you should be able to reach your performance goals easily enough without resorting to expensive measures, but by all means build the engine that you want. In my case I'm adding cubic inches and rigidity to the block and packing the air in rather than modifying the ports, so that I can build the engine for economy and long life. If I succeed at that it may well be the last SBB that I build.

Jim

Jim,

The valve seats look to be in pretty good condition but I have no history, so do not know whether they have ever been run with unleaded petrol. All the books i've read state that the early Buick 215 and Rover P5/6 heads should have the ex.seats replaced for use with unleaded so I'd assume the same would apply to the 300's, I'll talk to the guys who are going to do the heads and see what they recommend, although I'd like to avoid the expence of doing it if I can.

I am informed that the standard seats can be re-cut to take larger valves, I will definitely up the exhaust valve to 1.4" which if yours is going to be a blower motor would be a very worthwhile improvement as the existing small Ex. valve is the biggest restriction in these otherwise free flowing heads.

The following link provides some usefull flow comparisons by Dan Jones.

[www.leylandp76.com]

Regards and Happy New Year,

Kevin

You are probably right Kevin. I don't have specs for the years '64 to '68 and it would help if I did, especially for the '64 300, but I can expect my torque output to be very close to that of the 10.25:1 350 which was 375 ft/lbs if not more due to the blower. I don't expect max HP to ever be that much of a factor. The 350 was rated at 280 hp, chances are the 340 was a bit less, maybe 270 or so and since the 215 was at 200 I'd guess the 300 would be around 230-250hp. So purely by guesswork and extrapolation that might put me around 250 or so normally aspirated. If I was stopping there, a decent cam and some valve and port work would sure be a nice combination, but it should be a really good motor for a daily driver without it.

But considering that I am now boosting an Olds 215 to about 300 hp, will probably run the same blower drive ratio and go from a M90 to an M112 0n the 340 with better flowing heads and I would expect to go over 300 without too much trouble, how much more than that is anybody's guess. But what I do know from experience is that 300 is enough. It may not feel as impressive when a 265lb Dan Jones takes the co-pilot's seat, but that's a once in a blue moon occurrence and after all I would like to drive it on a regular basis. The new blower ought to cram about 24% more air in at the same drive ratio if all else were equal but of course it isn't. I don't think the 300 heads flow 24% better than the turbo Olds 215 heads, but with a 58% increase in displacement they just might.

So it's pretty clear that my whole approach goes back to the idea that displacement is king. In fact I'm doing something very similar to what you are, I'm building a stroker motor. Only I'm doing it with an iron block (heavier but stronger and more stable) and using stock parts.

I'd like to hear what your machinist has to say though about the valves and seats. I probably won't make any changes there unless I have to replace parts, but for a N/A stroker like yours it makes a lot of sense.

Jim



Edited 1 time(s). Last edit at 12/31/2007 04:22PM by BlownMGB-V8.

Jim,

I'll be making a decision shortly about who I am going to entrust the heads to, and will let you know what they recommend re the seats.

I'm sure your right that 300BHP is enough and 260+ BHP in my car is probably going to bring about the early demise of the SD1 axle, so a Jag rear end is probably on the cards and it will be helpful to me to get some of the critical dimensions regarding the location fore and aft, and the installed height of the diff in the car, the rest I can work out.


Kevin.

So far I've only trashed one axle (stock MGB, wore the ring and pinion out soon after installing the blower motor) so your SD1 my live longer than you expect, but I will be posting the critical dimensions on the Roadmaster thread. I slow down a lot in the winter, but I'm going to do my best to keep plugging away at it. For my roadster though I'm still watching for choices in differentials. I may not get that sorted out for a good while but I don't think it will be Jag based.

265 hp in a N/A engine will certainly make for an exciting car, especially if you can use strong enough parts to raise the rpm limit to around 6500 or 7K. That extra 1000rpm adds a lot more than most people realize.

Jim