BIG BLOCK IN A C4

johnny86convert · April 05, 2003, 06:59:57 AM

HELP.HELP.HELP.Mate wants to put a bog block in a C4 he has, saw an article in VETTE magazine, red 87 convertable on front cover maybe 5/6 years ago, any help in finding the article will mean the birth of one truly, mean gutter slapper YEEEE HAAAA please email pete at aviators@optusnet.com.au ;);););0

Brutus · April 05, 2003, 03:47:20 PM

He might want to check the relevent RTA rules regarding that first. Wouldn't want to get knocked back on such a project after all his work only to find he's unable to get it registered.
There hasn't been a BB in a Vette since 1974 tho you can't tell that to some people.:b2

Vette Obsessed · April 08, 2003, 01:42:01 PM

I would agree with Brutus and strongly recommend checking with the RTA and an automotive engineer before starting anything.

I have an article from Vette magazine from a few years back about a C4 big block conversion (454 into an 87) and can get a photcopy to you if it helps - scanning isn't really possible for me right now though.

rebel · April 08, 2003, 03:30:11 PM

JH, agree with both Brutus and VO re engineering check.

Also, try doing a search across Vette Mag's site and see if it brings up any articles of relevance ...

http://www.vetteweb.com

johnny86convert · April 08, 2003, 04:10:53 PM

VO.........my mate would be very appreciative, thats the article he was talking about, my fax at work is 0244643291 if that will help......moochas gracias.....by the way if my black beauty isn't ready for the convention,looks like where bringing the 86 left hook convertable, my mate steve wants to get a broom handle and another steering wheel and put it on the rightside of the car so he isn;nt left out LOLOLOLOLOLOLOLOL should be a hoot. went to fletchers 60th on sat what a hoot, seeya in canberra....wanta drag??????

johnny86convert · April 14, 2003, 08:29:03 PM

big thanks to VO for faxing the article today, would love to photo copy the article in canberra at ridges, seems like where on the right track with a very reputable engineer saying he can go up to 492 according to the weight of the 87 convertable its being dropped into..........four sleeps to go....also mine won;t be ready so where bringing the 86 convertible left hook, should be fun, seeya there guys.....sorry to hear about geoff ashton

johnny86convert · April 14, 2003, 08:30:27 PM

big apologies its ross ashton,sorry guys

Brutus · July 20, 2003, 07:43:18 PM

Here's a bit more info I found on the BB - C4 swap that I thought might be of help.

"if you put a bbc with aluminum heads, intake and water pump in , in place of the standard iron small block you only gain about 50-70 lbs, not enough differance to cause any problems at all, , I have worked on several of these swaps now and Im in the process of getting ready to do another one,heres whats needed
steering rack mounts cut and rewelded 3/4"-1" farther forward (that of course means the power steering pump lines/steering shaft, need to be extended 3/4" also)
small notch (starting at rear and going 3" forward from rear edge X 3/4"deep X 5" wide works well in rear top surface of (K) frame cross member to clear damper and pulley)(if you use an internally ballanced big block with the 6.75" dia. damper you can most likely skip the notch but with the 8" dia damper its necessary, and some oil pans will also require the back 1 1/2 of the (K) frame to be notched at an angle slopeing to the rear to clear them so youll probablly need the notch of some kind anyway)(and yes before you ask you could shim/modify the motor mounts up to get the clearance, but that would slightly raise the weight center and slightly effect the handleing, and that also makes the windshield motor and distributor clearance a bigger problem, a 1985 blazer wiper motor can be modified for greater clearance on the valve cover and swapped in to gain valve cover clearance)

air conditioner shrouding fiber glass on pass side foot well around the air conditioning on the firewall needs to be modifyed for clearance, (the fiber glass cover from a LT5 makes this easy)(evaporator houseing cover)

1971 bbc vette exhaust manifolds (or custom headers) and all brakets/pulleys (mods needed here)
(see the post on building your own headers)
oil pan needs to be only 7.5" deep max

3" hood scoop unless you run a low rise intake and carb or a low height efi system

for a step by step instructions with pictures get a copy of the august 1998 vette magizine article( starts on page 34)it helped quite a bit the first time

otherwise its almost a drop in deal, but keep in mind that youll need a bigger radiator, the trans will not last to long with that amount of torque and it may not pass emission testing and a small size starter is needed, and your windshield wiper motor needs to be replaced with a much smaller one,(I don,t remember where we got them but alittle measureing and a trip to the salvage yard took care of that problem, and no tall valve covers don,t work well!

btw install the short block then add the heads with it in the car its FAR EASIER THAT WAY than trying to install the long block

BTW the earlier cars like the 1984-86 (Im not sure what years exactly)dont have the heavier forward frame braceing above the stearing rack that makes this swap more difficult to do! I have worked on this swap on the 84, 85, and 86 cars so I know they work fine, the later cars like the 1992 with the heivier forward frame braces above the stearing rack look like they will be more dificult but still do-able with some extra work, btw theres a guy at ARIZONA SPEED AND MARINE that has one you might want to talk to .just a few points
an all aluminum bbc WEIGHS LESS THAN AN IRON SMALL BLOCK so the HANDLING IMPROVES
an aluminum head, intake and water pump bring a bbc engines weight to within 70 lbs of the stock iron small block, so handling is almost unchanged

any un-supercharged small block not useing nitrous or some other power adder that makes over 550 hp is highly likely to be at least somewhat unstreetable as a daily driver and your not likely to build a small block that makes "764 HP & 695 lb/ft at the flywheel" likely costs as much or more than a big block makeing similar power, look, good engine choice"
_______

Brutus · July 20, 2003, 07:45:21 PM

johnny86convert · July 20, 2003, 10:21:21 PM

Big thanks bob,my mate has moved on quite a bit since our first discussions and is assembling a nice bunch of ZR1 callipers and rims,block,heads car ETC and he's thinking of putting a small turbo on as well YEEEEE HAAAAA, hopes its ready for the big banks at lang lang next easter ;););););)

Brutus · July 22, 2003, 07:42:54 PM

I can only begin to imagine what I could get up to if the the front end of my C3 was accessible as a C4's.:b2

johnny86convert · July 22, 2003, 07:47:42 PM

Bob if you had that much power then you'd have to have that famous sticker my mum has on her rear window"GET OUTTA MY WAY i'M ON MY WAY TO BINGO" LOLOLOLOLOLOLO '););););)

Brutus · July 22, 2003, 08:11:18 PM

QuoteOriginally posted by johnnyholmes.86 convert
Bob if you had that much power then you'd have to have that famous sticker my mum has on her rear window"GET OUTTA MY WAY i'M ON MY WAY TO BINGO" LOLOLOLOLOLOLO '););););)

Yeah that's right....pick on the old guy.;39

rebel · July 22, 2003, 11:21:03 PM

I prefer this; in response to the sticker that reads "No Fear" .....

... "Some Fear! If there's no fear, you're not going fast enough!"

;laugh

Also, nice rocker covers.

77CVT · July 23, 2003, 09:03:36 AM

Bob, I thought by now you'd have copied the tilt front of your mate's C3 in the States by now.

Brutus · July 23, 2003, 09:38:36 AM

QuoteOriginally posted by 77CVT
Bob, I thought by now you'd have copied the tilt front of your mate's C3 in the States by now.

Don't think for one minute I haven't considered it Chris, but having seen his up close, I'd need a year just to detail the underside of the flip front. It wasn't pretty and detailing certainly wasn't one of his strong points.:b2