SB to BB Conversion

Tony Radford · #1 (**permalink**) 06-03-2003, 03:59 AM

I have to ask, has anyone undertaken the task of converting a small block Unique to a big block? When I asked Alan Weaver about it, he suggested that it would be difficult at best. Relocation of the motor mounts, replacement of the headers, possible need to remove the body, suspension changes and probably a host of hassles I haven't considered. The car is currently perfect as far as engine performance and handling is concerned and I'm probably an idiot for even considering an upgrade. I spend enough time at car shows and cruise ins that the additional mass under the hood would increase the thrill. Seeing a pair of quads sitting on a big block is awesome to me. Does it make a lot more sense for me to sell my car and start over with a new build? I love my car (color, set up, finish, etc.
What do ya'll think?

Clois Harlan · #2 (**permalink**) 06-03-2003, 06:26 AM

Like you I just had to have a big block although my small block was just perfect. My motor mounts stayed in the same location only not as tall (about 1 1/2") shorter. Had to replace my headers, transmission, starter, remote oil filter and routing of required lines, and the thing you will really love is the need for a hydraulic throw-out bearing.

Now I have this big a$$ engine that will absolutely climb trees but I can't hardly work on (especially on the drivers side when you need to change spark plugs you will find the steering column is in the way as will be your brake lines, and reservior for your throw-out bearing. Also, many times the FE engine runs a lot warmer than a small block. If you live in a city with long stop lights (eg: Dallas) you may find yourself getting nervous on thos 100 degree days.

Now the good news is you will have unbelievable torque but unless you go with a TKO II or some other trans w/ overdrive your top end will be considerably less because w/ a toploader and 3.50 or 3.73 gears you will be turning about 4000 rpm at 70 mph. Highway cruising at 4000 or 5000 rpm's make me nervous over long periods of time. But if you intend to drive your car at road races or drags you will love it. Coming out of a turn you will be able to launch down a straight away extremely fast.

Everything is a tradeoff and it all depends on what you want your car to do or look like. If I had overs I would go with a 408 stroker and a TKO II. Parts are a lot cheaper and easier to get. Just my opinion.

Just be happy with what you have.

Clois

Tony Radford · #3 (**permalink**) 06-03-2003, 06:49 AM

Clois, thanks for the insight. Serviceability does look like a serious compromise between the BB and SB. I'm less interested in the torque increase than I am the aesthetic appeal. Probably not a good reason for going through the grief. I'm currently running a toploader with a 3.31 rear end. Maybe the answer is to get a bit fancier with the Windsor and leave it at that. I don't want to create a maintenance monster.

Cracker · #4 (**permalink**) 06-03-2003, 06:58 AM

Tony, it was nice meeting you on Sunday at Dreamland! If you seriously consider the swap I would recomend Robinson Racing in Cumming to handle chasis modifications. They have done quite a bit of work on my car and Barry Trivette is a suspension expert. You will not be dissapointed - the only problem is getting quick service because they build SCCA custom race chasis for racers around the country. Best of luck!

Tony Hull
Cracker

Tony Radford · #5 (**permalink**) 06-03-2003, 08:24 AM

Tony, likewise. Our little brotherhood is growing. Great bunch of guys. I appreciate the info. I'm still weighing the data (nothing's easy,eh?). I will certainly log Robinson as a potential co-conspirator!

T

BigEasy · #6 (**permalink**) 06-03-2003, 03:53 PM

Tony;

Tough question, I can see why you are struggling with the decision.

A couple of things to consider:

--as Clois mentioned, a BB is tight to do work on. I replaced my valve covers this winter, and had to literally "fabricate" a tool to reach the back/bottom hold-down bolts.

--BUT, I do like the sound/torque/2x4's, etc---I do agree with you on that one.

--Might not want to take the chance to "compromise" your already pristine car by ripping it to pieces and making it swallow a BB, only to be not completely satisfied with the end result? Maybe tear up more in the process? Paint, etc.

--I think if you REALLY, REALLY want to go this route, I would sell your very nice SB, and start from scratch---this way you control the process, and it's all designed for the BB to start.

--Order a Kirkham like TC, get the BB and aluminum shell

It's a tough decision. You have the beautiful redhead today, but you may never really be satisfied until you get that Big Blonde (BB).

Best of Luck in your decision.

BigEasy
Charlie

Tony Radford · #7 (**permalink**) 06-04-2003, 03:55 AM

Thanks Charlie. That's the biggest issue (besides the cash required), the thought of trashing a nice car. I have a pretty severe rear main seal leak in the Windsor that I've got to do something about (I'm on my third seal in six months). It's manifesting intself as a motive for upgrading or replacing the engine. It probably makes more sense to do a stroker and leave the car profile alone.