I just got my 91 integra, I was planning on putting a vtec head on it. I heard that it can cause problems in the bottom end, how likely is it? How much would it cost? How long would it take if I had an experienced mechanic do it for me? Thank you

B Eazy

 

the most common problem is over reving the block.
if you're not planning to upgrade the block, then keep the revs safe (at the sacrifice of performance).

I personally wouldn't go more than 7800rpm on a good condition LS block.

 

This is why LS-Vtec motors get a bad rep.

Do it the right way & build the shit out of your block. Then you won't ahve to worry bout anything breaking.

Bore it / Sleeve it / Forged Internals = no breakage! & High reving power house!

If you leave the block stock.. you have a ticking time bomb in your engine bay.. it's just a matter of time b4 it blows witht that vtec head on there

just my .02

 

Can any of you give an estimate to how much it would cost to build up the block with the cost of a ls/vtec conversion?

 

i have a 91 ls and i am gonna have a guy rebuild the motor over the summer then sell the rebuild head to pay for a vtec head. i am gonna put in rods, probly eagle pistons,rings opins.. anyways what vtec head should i get pice and performance wise, i was thinkin of a si head but if i can a gsr or and r which ever is better, is a ls/vtec good to boost b/c i was plannin on turo chargin it and suggestions

 

I would think that your best bet is to find a used vtec engine and replace the whole thing.

Here is the problem with just replacing the head. First, you will need to find the head. You might be able to find a decent used one for 2-400 bucks. But even then, you're still going to have to have the head worked. It will need to be milled (resurfaced), and pressure checked to make sure there are no cracks. In addition, if it has alot of miles, it will be recommended to have a valve job as well. All in all, you're looking at over 600 bucks, which is what it might cost you to buy a re-furbished one. If you have the head all ready, an experienced mechanic can probably replace it in 5-10 hours if they don't run into any problems. Plus, you will need an upper gasket set. My guess is over $1000 easy to have it done. Here is where it gets complicated. The bottom half of your engine is old and worn, and the top half is good. When this happens, the added pressure, (from the new head not being worn anymore), will cause more pressure on your rings. If you're rings are old and worn, (which on a 91 integra they probably are), then the increase in pressure will cause them to leak more and you will probably burn alot more oil. I've heard as much as half a quart every 400 miles. What you COULD do, is while the head is off, drop the oilpan, and remove the rod caps. Take the pistons out, rehone the cylinder, and replace the rings and rod bearings. Now your looking at more money, and you've practically rebuilt the entire engine, and spent probably well over $1500 bucks and you still have a problem with over-reving the block.

The alternative I mentioned earlier - find a decent used vtec engine with low miles. Might be able to for around $1000, then pay to have it swapped. It might cost just as much, or even cheaper, but now you have a good engine all around with low miles. Do you see the benefit?

 

Yeah I do, but if I'm going to do all that, I'll wait till my next car. I get 8000 to put towards a car when I get out of school. I'm thinking about buying a 96 cobra.

 

I would get a Type R before I go with a Cobra.Nothing against Mustangs because I like them also. If you plan on getting a Cobra why would you waste your money on the LS/Vtec.Just keep the Teg like it is ...IMO

 

Yeah... get a type-r... i'm personally not a mustang person and i think you will find that a japanese car is much more solid and well built.

 

What kind of companies sell good internals for a 91 integra?