After gathering EVERYTHING, and then some, to swap a Rover 3.9 into my MGB I had a completely rebuilt '64 4 bbl 300 (with low compression pistons) fall into my lap. I completely changed horses and, in the last few weeks, now have most of what I need for this engine and have a few questions. I ordered a set of 10:1 pistons from Mark at D&D along with a Crower 50232 cam and a set of appropriate valve springs. I have the original 4bbl manifold and a new in the box Edelbrock 500 carb. The block has not been decked from what I can tell and the heads have been very lightly surfaced with no port work done. I have an original '64 bell housing and my car has 3.73 R&P along with an F-body T5 with a .63 5th gear. Curb weight will be about 2200-2300 lbs. My questions are these. Will this combination be tractable or peaky? Have I made the right choice in CR or would have 11:1 been better? With what I have, should I use composite or shim head gaskets? Can I make a Buick HEI distributor work or should I stick with a converted point type? My water pump pulley is much bigger than my crank pulley. Wll my pump turn too slowly? Should I spin my pump with a drill to pre-lube before starting for the first time or will that wash the cam lube away (I know about vaseline in the pump)? And finally, and I know there are a LOT of variables, what kind of power should I expect from this engine? I've been hanging out here a lot trying to learn all that I can and I appreciate the knowledge you share. David
everything you need to know about that is here the 10:1 are fine u need a bigger cam an aluminum intake headers a upgradeded oil pump... etc etc... now you need to tell me specific questions from now on...
10:1 will be fine with that combo, 11:1 gets a little tricky with pump gas. Probably go with the steel shim head gaskets as you want to keep at least 10:1 (assuming high grade pump fuel is ok). Don't bother with an HEI, they don't fit well and are out dated. Best route is a new distributor such as a Mallory Comp S/S. All electronic, uses HEI wires, fully tunable, etc. Power should be nice and linear. Should pull nice and strong to 5300 ish. You should investigate the pulleys, the crank pulley is normally a little larger in diameter. On my `64 300, the crank pulley is 6-1/2" dia and the w/pump pulley is 5-1/2". You definately want to prime the oil pump, by running it before hand with a drill and primer tool. You will not wash the lube off of the lobes as the cam lobes do not see pressurized oil, just splash oiling when the engine is running. This is why you have to break in a cam at elevated RPM to flood the cam with oil to keep it cool during break-in. Guessing you will be between 250 & 275 hp TA Performance has an extensive catalog available for download from our website at www.taperformance.com also available in hardcopy if you call to request one.
Well, as a lot of things go my completely and professionally rebuilt 300 has to be, you guessed it, completely rebuilt. I just delivered the block, heads, pistons/rods and crank to the machine shop. After going into it to change out the pistons and cam/valve springs, I discovered a very, very low time engine but with dirt in the timing cover from the fuel pump opening, dirt in the heads, old, trashed cam bearings but the cam journals looked good, a rock hard front rope seal that obviously had not been changed, pitiful looking oil pump gears and a standard crank that had some very fine marks on the journals that the machinist said would require a polish only. I also found some rusty crud in one of the main block water passages and a pencil in the oil pan. It had been stuck in the dipsick tube hole to keep dirt out. The whole time I was taking it apart I was still hearing the seller say "just change the oil and fire it up! It'll be fine." My $600 "deal" is has cost me another $1200 in parts and machine work to get it right. In the end, I guess that $1800 for a fresh '64 300 built the way I want it is still not too bad.
I'd say it isn't bad. I paid $400 for a reman short block (340) and figured I got a good deal. Rod bolts are mismatched and it'll have to come apart for cleaning, reassembly, and maybe different pistons, but still not bad. Add the cost of a decent set of heads and some better pistons and I'm right up there with you. Jim
A few years ago I built a crossflow MGB engine with twin DCOE's and all the bells and whistles. It puts out about 140 HP. I just went through my mental files and I spent over $2000 just on the head, carbs and cam. I guess this 300 is probably the power deal of the year compared to that.
I'm making progress. I got my block back from the machine shop with new cam bearings, freeze plugs and a fresh hone along with my polished (standard) crank and my heads with D&D's valve springs and machined valve guides and spring seats to suit the 50232 cam. I found a set of Clevite main and rod bearings for ~$80 shipped, a set of Hastings Moly rings for my Zolner +.030 pistons and all the other bits needed to go back fresh. I'm going to use a modern front seal but I'm still on the fence about the rear. Reading the archives just makes things worse. Now I need some free time to put it all together.
Well, all I can say is, rope seals leak and as they age they leak more. If you can do some porting work on the heads before they go back in that should wake it up pretty well, and both Nick and Dan Jones have put oversize valves in those heads. Dan's flow numbers looked mighty good afterwards. I'm building a similar engine, but using a 340 short block. It's a slower project and I'm sort of scouting about for a better set of heads than the ones I have on hand. We've also got a 455 MGB project coming along. That'll be pretty insane. Jim
I've been following your progress on the BBB car. It's going to be a real beast. Thanks for the tip on the rope seal. David
