Carb first or Right to EFI after install ? - Lateral-g Forums

**waynieZ** · #1 09-22-2009, 06:46 PM

Hi Guy I am looking for a couple of opinions here . When I get my car back and install the engine should I run it with the carb that came with the engine , or put the XFI on right away? The only fuel system I have will be set up for EFI, but I guess the dirrerence is only a fuel regulator. I have both setups carb and EFI. Just wondering if the EFI will make it harder to get running for the first time?
Second is the engine has been sitting for 2-1/2 years waiting to go in . I've turned it over a few time and put oil pressure in more than a few time . Do you think my valve springs will be ok or do you think they may have taken a set for lack of use? Its a solid flat tapped no big spring pressures. Thanks

69MyWay · #2 09-23-2009, 08:29 AM

If you are running a 60 psi electric pump...that will be one heck of a regulator to cut it down to 4 or 5 for the carb...so I would suggest changing the pump if you run the carb.

Has the engine ever been started with the new cam? If not, you will be going through the break in process.

Unless your EFI is dialed in, or you have a reliable proven program, I would suggest starting and breaking in the cam on the carb.

Last year we did a EFI start from scratch and "break in" - we were having some programming issues, so we were not able to start and go to 2,000 RPM right away ....and as a result we may have compromised the break in process.

If the engine/cam has already been broken in - I'd go straight to the EFI.

As far as the springs???? I'm not an expert there, and would have to defer - but I would think it would be okay unless you are running something super extreme.

**GregWeld** · #3 09-23-2009, 09:00 AM

Wayne

You didn't mention what EFI you plan to use... Many of the companies have programs preloaded that are "close" to your use. I'm just guessing here - but you may look through some of the preloaded versions to see what you can find for start up purposes. Jody may chime in here with a bit more detailed info on this - or someone else perhaps.

Are you going to run break in springs for the solid flat tappet cam? Most guys I talk to or know recommend that - over running the springs you plan to use. Flat tappet cams - and solid cams even more so - really need the break in procedure to be right on. Also don't skip on the oil additive and cam break in additives! You've got to have the zinc.... Comp Cams now sells an additive for this.

http://www.compperformancegroupstore...Category_Code=

I agree that if you're going to run a carb - you're going to have to change fuel pumps for the break in.

Vegas69 · #4 09-23-2009, 09:09 AM

I'd go right to the intended fuel system. Bill Mitchell breaks in his engines doesn't he? I bet it has a roller cam in it. If it doesn't you can run Valvoline VR1 racing oil or an additive like mentioned for a flat tappet camshaft.

**waynieZ** · #5 09-23-2009, 02:24 PM

The engine is already broken in from Bill Mitchell. I was concerned if the spring could go bad from sitting so long in one position ? Its a solid flat tappet cam that came in the engine.
As far as a tune another member on here 67ragtp has a 427 version of this engine with the same XFI I'm going to use . He said he will give me a copy of his tune to get me started . I called Fast they said it should be a good start.
I was just worried about extra problems on a new setup. Wayne

67ragtp · #6 09-23-2009, 06:45 PM

Wayne,

When your ready for the tune file just hollar. As far as the springs go turn the engine over 1 or 2 revolutions every couple weeks that will put the compressed valve springs in a different location. If its gonna be a while you could pop the covers off it and back the lash off completely, re-adjust when ready IC/EO pretty simple.

Also aeromotive makes a nice carb regulator for the a-1000 which is an efi pump. I ran it both ways worked like a champ, If I had the regulator Id send it over but I sold it.

Rich

jski67 · #7 09-24-2009, 06:47 AM

Since the cam is already broken in, I'd go for the efi.

I just started mine for the first time this past weekend on a test stand. I'm running a Holley Commander. I loaded a base map close to my big block (489) and it fired right up, no issues. If you had to break in the cam I'd think about the carb, but since you don't, just go for it.

This was first first complete engine assembly ever and it worked great...if I can do it, anybody can!

Good luck,
Jason