Thinking about taking my 400 I rebuilt about 10 or so years ago and boosting some hp out of it. When I rebuilt it last time around, I never bored it out, just put new rings and a new crank in with no extras in terms of internal components. Didn't have much money back then. Now, even though I don't have a mile on this motor due to my father not rebuilding the body as planned and him passing on, I'm rethinking if I should, while it's out of the bay and all, take it down and upgrade components. It is a B block and A heads from '65. I figure with new rings and honed out it probably runs about 350 hp with the Weiand intake on it and 650 holley. However, I would like to achieve close to 400 if I can out of this hog. I don't want to get away from the stock look on the outside too much, so no aggressive two carb setups, blowers, or ultra high rise intakes. Simple on the outside, but enough horses to really move and run a decent 1/4 on the inside. My recommendations are as follows, but by no means specific since I'm not sure what to go with exactly and I certainly welcome any specs associated with items below or some I may have missed:

1. Bore it out to .040 or more? thoughts?
2. New flat top aluminum pistons
3. More aggressive cam than stock
4. I would like to keep the heads, so maybe port and polish them I don't know?
5. Roller rocker hydro everything (rods, tappets, lifters, arms)
6. maybe a 850 carb to keep up, with edelbrock alum intake?
7. Put some headers on it with x-pipe system. (heard this doesnt really fit well in a '64 cutlass)

Everyone's thoughts on what they would do to increase to around 400 hp would be great. Even if you've went through the same type of ordeal and boosted performance I would be happy to listen to things others have done with their early 400 motors. I havn't got money to burn exactly, but I'm comfortable putting a good deal into it if I need to. I would be doing most of the work myself, but with guidance, since I've never interchanged more than stock components in the past and have only done one complete tear down motor, this one, ever. But, I'm a mechanical engineer by trade and have turned wrenches growing up, so I grasp concepts well and understand most of the jargon, but not all I suppose.

 

C'mon. Nobody has any experience or thoughts on what they have or would do to this type of motor. I'm sure all those '65 guys with a 400 have cranked out 50 extra horses in one way, shape, or form and can offer tips on best bang for your buck. I'd really appreciate any input.

Dom

 

Since you have an older engine, and I'd personally want to keep something like that for as long as I could, I'd just go w/ the .40 over and flat tops, an intake and carb, a mild cam, clean up the heads, and some headers, and an ignition. Just the few mild up-grades will make a big difference. Don't go up too high w/ the compression, as you want to run on pump gas. Seems like you want a sleeper and I think you're thinking right. This is only my opinion, but having built engines for about 35 years, started in high school when everyone was driving something hot, just the bolt-ons and minimum machine work really wakes up an engine that was mfged. before the emissions days. Go mild and inexpensive, and keep the engine going f/ years to come. A '65 is something you need to keep around f/ as long as you can. No many around anymore. The 223ci 6 cyl. from my '62 Ford p/u is something I'll never get rid of. It still has the standard bore, original cam and lifters and standard bearings. From back when they built them hard and to last. Things like that need to be preserved. Things have changed greatly from those days, and IMO it's part of automotive history.

 

Thanks for the feedback. Just a couple questions. When you say clean up the heads, what does that entail exactly? Just clean them up or actually port, polish, and machine them? Thanks. Also, with a mild cam that means something other than what is currently in it right? Like a slightly longer duration and lift than stock. If I'm reading you right, then you are saying not to upgrade the lifters, rods, or valve components? I really appreciate all the input as I would like to take the sleeper approach you are correct. What would constitute going to high with compression? Would adding some of the components I originally listed do this? Good thoughts, I will take this to heart.

 

First off i would only bore it as much as you need.

1- Buy some nice light pistons shoot for around 10 to 1 compression
2- run a modern grind cam
3- get the heads ported
4- good balance
5- Good 750 carb
6- Headers

Just that should be good for 400hp Im sure there are some members here that have built up a 400 that will chime in. Good luck with the build.

 

Recommendations on brands, specs, places of purchase for items 1-6 you discussed?

 

Since you are starting over anyway build a 455 and be done with it.

 

 

Well ive never built a 400. So im not the best person to give you advice on what exactly to use. But i can tell you the specs on my motor and what it does.

455 .060 over
N crank
Silvolite cast pistons (my combo 9.7 to 1)
Stock rods
ARP hardware
Main cap straps
good balance
6 qt pan
Melling H/V pump
JM 22-2510 cam (230/236 @.050 .512/.523 lift 110)
crane high rev lifters
Ga home ported heads (by SteveO) 2.07/1.71 stainless valves xovers filled comp roller tip rockers
performer intake
holley 3310-2 750 vac secondary
stock fuel pump
hooker 1-3/4 headers
stockish GM HEI



This motor has had alot of miles and abuse. Spin it up to 6k. best pass at the track 12.54 at 107. Thats in my 64 F85 4dr 3590 lbs with me in it. 3.08 gears and 255/60-15 street tires and B&M 2800 converter. never got it to hook, and the trans kinda sucks. I hope this helps.

 

Sell the 400 to someone with a 442 wanting a stock motor for a restoration. You said you are going to bore anyway you you have to buy pistons. You won't find any 400 pistons unless you have custom made or find NOS$$$$$. 455 pistons are still made and can also be found laying around everywhere. Hell I have a new set of L2323F30 on Ebay right now The bigger cubes are free horsepower and most importantly free torque.

 

I found pistons (not custom or NOS) well prior to this email. NOt an issue. Besides I don't want a 455. Not my cup of tea and I don't believe it to be a superior motor. But, that's just my opinion.

 

Well I don't know of any inexpensive ones that will make any kind of compression. Supercars sells a them but they are almost $500.00 for a set. The difference will buy a good bit of macine work. I have been down the road looking to build a 400. Its a great motor but will costs a good bit more to build and will make less power. More power to you to build what you want. Just trying to give you some freindy advice and save you money at the same time.

 

 

Try not to laugh, but the reason I believe this is that the early 400 engines rev higher than any other big block. They will rev higher than a 425 or a 455, stock of course. Got a little less piston mass too if I recall right and correct me if I'm wrong of course. These things will turn almost 7000 RPM, comfortably. I don't recall many other big blocks that can claim that potential. Besides, I already have a big block and do not want to go through locating, haggling, purchasing, and picking up a 455 when I know I have a good motor right now. You never know when your going to get screwed and end up with a stress cracked block and you take a chance everytime you go out there and get one. I'd rather focus my efforts on building the block I have, which is a pretty damn good starting point I think. Sure, it would be nice to give it to a guy that needs it for his '65, but I plan on getting one of those some day too if my wife will let me!!! I like the big blocks and don't get me wrong bigger is always better, but weight comes into play as well. The car is dang heavy enough as it is compared to others "muscle" machines of the era.

Anyway, back on topic, any specs would be beneficial to those gearheads out there that would optimize this motor. Thanks.

 

Another Olds myth. Just because its on the Olds FAQs doesnt mean its the truth.

 

I don't know, I didn't even see this in the olds FAQ you speak of. In any case, I read this in an article back in '92 or '93 from Rod and Custom magazine. I'm not saying everything printed in magazines is true, but most do their research before making such claims. Anyway, I'm not saying I know this for a fact, but I doubt they would put something like this to print without having some of their experts who build motors everyday for Rod and Custom testify to the fact. In any case, this is off the topic and I would like to discuss what can be done to this motor as stated in the stipulations outlined in the original post. Back to the basics here.

 

So, what are those recommendations if one was building a 400 big block to be a formiddable street machine. I have to have some specs before taking on a job of this magnitude. My expectations were made clear in the first post of this thread. What would you do if you had this motor? I would like to hear from some master builders, so I can run with specs and start the process if I have the deniros.